ST72561
8-bit MCU with Flash or ROM, 10-bit ADC, 5 timers, SPI, LINSCITM, active CAN
Features
Memories 16K to 60K High Density Flash (HDFlash) or ROM with read-out protection capability. InApplication Programming and In-Circuit Programming for HDFlash devices 1 to 2K RAM HDFlash endurance: 100 cycles, data retention 40 years at 85C Clock, Reset and Supply Management Low power crystal/ceramic resonator oscillators and bypass for external clock PLL for 2x frequency multiplication 5 power saving modes: Halt, Auto Wake Up From Halt, Active Halt, Wait and Slow Interrupt Management Nested interrupt controller 14 interrupt vectors plus TRAP and RESET TLI top level interrupt (on 64-pin devices) Up to 21 external interrupt lines (on 4 vectors) Up to 48 I/O Ports Up to 48 multifunctional bidirectional I/O lines Up to 36 alternate function lines Up to 6 high sink outputs 5 Timers 16-bit timer with 2 input captures, 2 output compares, external clock input, PWM and pulse generator modes 8-bit timer with 1 or 2 input captures, 1 or 2 output compares, PWM and pulse generator modes 8-bit PWM auto-reload timer with 1 or 2 input captures, 2 or 4 independent PWM output channels, output compare and time base interrupt, external clock with event detector
LQFP32 7x7mm
LQFP64 14x14mm
LQFP44 10x10mm
LQ FP64 10x10mm
Main clock controller with real-time base and clock output Window watchdog timer Up to 4 Communications Interfaces SPI synchronous serial interface Master/slave LINSCITM asynchronous serial interface Master-only LINSCITM asynchronous serial interface CAN 2.0B active Analog Peripheral (Low Current Coupling) 10-bit A/D converter with up to 16 inputs Up to 9 robust ports (low current coupling) Instruction Set 8-bit data manipulation 63 basic instructions 17 main addressing modes 8 x 8 unsigned multiply instruction Development Tools Full hardware/software development package
Table 1. Device Summary
Features Program memory - bytes RAM (stack) - bytes Operating Supply CPU Frequency Max. Temp. Range Packages ST72561AR9/ST72561R9/ ST72561J9/ST72561K9 60K 2K (256) ST72561AR7 48K 2K (256) ST72561AR6/ST72561R6/ ST72561AR4/ST72561J4/ ST72561J6/ST72561K6 ST72561K4 32K 1.5K (256) 16K 1K (256)
4.5V to 5.5 V External Resonator Osc. w/ PLLx2/8 MHz -40C to +125C LQFP64 10x10mm (AR), LQFP64 14x14mm (R) LQFP44 10x10mm (J), LQFP32 7x7mm (K)
Rev. 7
October 2008 1/265
1
Table of Contents
1 DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 PIN DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3 REGISTER AND MEMORY MAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4 FLASH PROGRAM MEMORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.2 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.3 STRUCTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.4 ICC INTERFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 4.5 ICP (IN-CIRCUIT PROGRAMMING) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4.6 IAP (IN-APPLICATION PROGRAMMING) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4.7 RELATED DOCUMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4.8 REGISTER DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5 CENTRAL PROCESSING UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 5.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 5.2 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 5.3 CPU REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 6 SUPPLY, RESET AND CLOCK MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 6.1 PHASE LOCKED LOOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 6.2 MULTI-OSCILLATOR (MO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 6.3 RESET SEQUENCE MANAGER (RSM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 6.4 SYSTEM INTEGRITY MANAGEMENT (SI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 7 INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 7.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 7.2 MASKING AND PROCESSING FLOW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 7.3 INTERRUPTS AND LOW POWER MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 7.4 CONCURRENT & NESTED MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 7.5 INTERRUPT REGISTER DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 7.6 EXTERNAL INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 8 POWER SAVING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 8.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 8.2 SLOW MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 8.3 WAIT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 8.4 HALT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 8.5 ACTIVE HALT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 8.6 AUTO WAKE-UP FROM HALT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 9 I/O PORTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 9.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 9.2 FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 9.3 I/O PORT IMPLEMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 9.4 LOW POWER MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 265 9.5 INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 9.6 I/O PORT REGISTER CONFIGURATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
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10 ON-CHIP PERIPHERALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 10.1 WINDOW WATCHDOG (WWDG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 10.2 MAIN CLOCK CONTROLLER WITH REAL TIME CLOCK MCC/RTC . . . . . . . . . . . . . . . 59 10.3 PWM AUTO-RELOAD TIMER (ART) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 10.4 16-BIT TIMER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 10.5 8-BIT TIMER (TIM8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 10.6 SERIAL PERIPHERAL INTERFACE (SPI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 10.7 LINSCI SERIAL COMMUNICATION INTERFACE (LIN MASTER/SLAVE) . . . . . . . . . . . 121 10.8 LINSCI SERIAL COMMUNICATION INTERFACE (LIN MASTER ONLY) . . . . . . . . . . . . 152 10.9 BECAN CONTROLLER (BECAN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 10.1010-BIT A/D CONVERTER (ADC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 11 INSTRUCTION SET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 11.1 CPU ADDRESSING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 11.2 INSTRUCTION GROUPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 12 ELECTRICAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218 12.1 PARAMETER CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218 12.2 ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 12.3 OPERATING CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 12.4 SUPPLY CURRENT CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 12.5 CLOCK AND TIMING CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 12.6 AUTO WAKEUP FROM HALT OSCILLATOR (AWU) . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 12.7 MEMORY CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 12.8 EMC CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230 12.9 I/O PORT PIN CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 12.10CONTROL PIN CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 12.11TIMER PERIPHERAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 12.12COMMUNICATION INTERFACE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . 242 12.1310-BIT ADC CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 13 PACKAGE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 13.1 PACKAGE MECHANICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 13.2 THERMAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 13.3 SOLDERING AND GLUEABILITY INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 14 DEVICE CONFIGURATION AND ORDERING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . 251 14.1 FLASH OPTION BYTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 14.2 TRANSFER OF CUSTOMER CODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 15 DEVELOPMENT TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 16 IMPORTANT NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 16.1 ALL DEVICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 16.2 FLASH/FASTROM DEVICES ONLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 16.3 ROM DEVICES ONLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 17 REVISION HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
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ST72561
1 DESCRIPTION
The ST72561 devices are members of the ST7 microcontroller family designed for mid-range applications with CAN (Controller Area Network) and LIN (Local Interconnect Network) interface. All devices are based on a common industrystandard 8-bit core, featuring an enhanced instruction set and are available with Flash or ROM program memory. The ST7 family architecture offers both power and flexibility to software developers, enabling the design of highly efficient and compact application code. Figure 1. Device Block Diagram
option
The on-chip peripherals include an A/D converter, a PWM Autoreload timer, 2 general purpose timers, 2 asynchronous serial interfaces, and an SPI interface. For power economy, microcontroller can switch dynamically into WAIT, SLOW, Active-Halt, Auto Wake-up from HALT (AWU) or HALT mode when the application is in idle or stand-by state. Typical applications are consumer, home, office and industrial products.
OSC1 OSC2
PLL x 2
OSC
PWM ART 8-Bit TIMER 16-Bit TIMER
/2
VDD VSS
POWER SUPPLY
PORT A PORT B PORT C PORT D PORT E PORT F SPI LINSCI2 (LIN master) LINSCI1 (LIN master/slave) WINDOW
ADDRESS AND DATA BUS
RESET TLI1
CONTROL 8-BIT CORE ALU
PA7:0 (8 bits)1 PB7:0 (8 bits)1 PC7:0 (8 bits)1 PD7:0 (8 bits)1 PE7:0 (8 bits)1 PF7:0 (8 bits)1
PROGRAM MEMORY (16 - 60 Kbytes)
RAM (1 - 2 Kbytes)
MCC (Clock Control)
WATCHDOG CAN (2.0B ACTIVE)
1On
some devices only (see Device Summary on page 1)
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3
ST72561
2 PIN DESCRIPTION
Figure 2. LQFP 64-Pin Package Pinout
OSC1 OSC2 ARTIC1 / PA0 PWM0 / PA1 PWM1 / (HS) PA2 PWM2 / PA3 PWM3 / PA4 VSS_3 VDD_3 ARTCLK / (HS) PA5 ARTIC2 / (HS) PA6 T8_OCMP2 / PA7 T8_ICAP2 / PB0 T8_OCMP1 / PB1 T8_ICAP1 / PB2 MCO / PB3
64 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
PF7 PF6 PD7 / AIN11 PD6 / AIN10 RESET PD5 / LINSCI2_TDO VDD_0 VDDA VSS_0 VSSA PD4 / LINSCI2_RDI PD3 (HS)/ LINSCI2_SCK PF5 TLI PF4 PF3 / AIN9 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 ei3 ei3 ei3 47 46 45 44 ei0 43 ei3 42 41 40 39 ei0 38 37 36 35 ei1 34 ei1 ei2 ei1 33 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
PD2 / LINSCI1_TDO PD1 / LINSCI1_RDI PF2 / AIN8 PF1 / AIN7 PF0 PE7 PD0 / SPI_SS / AIN6 VDD_1 VSS_1 PC7 / SPI_SCK PC6 / SPI_MOSI PC5 / SPI_MISO PE6 / AIN5 PE5 PC4 / CAN_TX PC3 / CAN_RX
AIN12 / PE0 AIN13 / PE1 ICCCLK / AIN0 / PB4 AIN14 / PE2 AIN15 / PE3 ICCDATA / AIN1 / PB5 (*)T16_OCMP1 / AIN2 / PB6 VSS_2 VDD_2 (*)T16_OCMP2 / AIN3 / PB7 (*)T16_ICAP1 / AIN4 / PC0 (*)T16_ICAP2 / (HS) PC1 T16_EXTCLK / (HS) PC2 PE4 NC ICCSEL/VPP
(HS) 20mA high sink capability eix associated external interrupt vector
(*) : by option bit: T16_ICAP1 can be moved to PD4 T16_ICAP2 can be moved to PD1 T16_OCMP1 can be moved to PD3 T16_OCMP2 can be moved to PD5
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ST72561
PIN DESCRIPTION (Cont'd) Figure 3. LQFP 44-Pin Package Pinout
OSC1 OSC2 PWM0 / PA1 PWM1 / (HS) PA2 PWM2 / PA3 PWM3 / PA4 ARTCLK / (HS) PA5 ARTIC2 / (HS) PA6 T8_OCMP1 / PB1 T8_ICAP1 / PB2 MCO / PB3
44 43 42 41 40 39 38 37 36 35 34 1 33 ei3 ei3 2 32 ei3 3 31 4 30 5 ei3 29 ei0 6 28 7 27 8 26 9 25 10 ei1 24 ei2 ei1 11 23 12 13 14 15 16 17 18 19 20 21 22 ICCCLK / AIN0 / PB4 ICCDATA / AIN1 / PB5 (*)T16_OCMP1 / AIN2 / PB6 VSS_2 VDD_2 (*)T16_OCMP2 / AIN3 / PB7 (*)T16_ICAP1 / AIN4 / PC0 (*)T16_ICAP2 / (HS) PC1 T16_EXTCLK / (HS) PC2 PE4 ICCSEL/VPP
PD7 / AIN11 PD6 / AIN10 RESET PD5 / LINSCI2_TDO 1 VDD_0 VDDA VSS_0 VSSA PD4 / LINSCI2_RDI PD3 (HS) / LINSCI2_SCK PF5
PD2 / LINSCI1_TDO PD1 / LINSCI1_RDI PF2 / AIN8 PF1 / AIN7 PD0 / SPI_SS / AIN6 PC7 / SPI_SCK PC6 / SPI_MOSI PC5 / SPI_MISO PE6 / AIN5 PC4 / CAN_TX PC3 / CAN_RX
(HS) 20mA high sink capability eix associated external interrupt vector
(*) : by option bit: T16_ICAP1 can be moved to PD4 T16_ICAP2 can be moved to PD1 T16_OCMP1 can be moved to PD3 T16_OCMP2 can be moved to PD5
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ST72561
PIN DESCRIPTION (Cont'd) Figure 4. LQFP 32-Pin Package Pinout
OSC1 OSC2 PWM0 / PA1 PWM1 / (HS) PA2 ARTCLK / (HS) PA5 T8_OCMP1 / PB1 T8_ICAP1 / PB2 MCO / PB3
1 2 3 4 5 6 7 8
32 31 30 29 28 27 26 25 24 ei3 23 ei3 22 21 ei0 20 19 18 ei1 ei2 ei1 17 9 10 11 12 13 14 15 16 ICCCLK / AIN0 / PB4 ICCDATA / AIN1 / PB5 T16_OCMP1 / AIN2 / PB6 T16_OCMP2 / AIN3 / PB7 T16_ICAP1 / AIN4 / PC0 T16_ICAP2 / (HS) PC1 T16_EXTCLK / (HS) PC2 ICCSEL/VPP
RESET PD5 / LINSCI2_TDO VDD_0 VDDA VSS_0 VSSA PD4 / LINSCI2_RDI PD3 (HS) / LINSCI2_SCK1
PD2 / LINSCI1_TDO PD1 / LINSCI1_RDI PD0 / SPI_SS / AIN6 PC7 / SPI_SCK PC6 / SPI_MOSI PC5 / SPI_MISO PC4 / CAN_TX PC3 / CAN_RX
(HS) 20mA high sink capability eix associated external interrupt vector
(*) : by option bit: T16_ICAP1 can be moved to PD4 T16_ICAP2 can be moved to PD1 T16_OCMP1 can be moved to PD3 T16_OCMP2 can be moved to PD5
For external pin connection guidelines, refer to "ELECTRICAL CHARACTERISTICS" on page 219.
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ST72561
PIN DESCRIPTION (Cont'd) For external pin connection guidelines, refer to "ELECTRICAL CHARACTERISTICS" on page 219. Legend / Abbreviations for Table 2: Type: I = input, O = output, S = supply In/Output level: CT= CMOS 0.3VDD/0.7VDD with Schmitt trigger TT= TTL 0.8V / 2V with Schmitt trigger Output level: HS = 20mA high sink (on N-buffer only) Port and control configuration: Input: float = floating, wpu = weak pull-up, int = interrupt1), ana = analog, RB = robust Output: OD = open drain, PP = push-pull Refer to "I/O PORTS" on page 46 for more details on the software configuration of the I/O ports. The RESET configuration of each pin is shown in bold which is valid as long as the device is in reset state. Table 2. Device Pin Description
Pin n LQFP64 LQFP44 LQFP32 Type Pin Name Level O u tput Input Port Input float wpu ana int Main function Output (after reset) OD PP
Alternate function
1 2 3 4 5 6 7 8 9 10 11 12 13 14
1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8 9 -
O SC1 3 ) O SC2 3 ) PA0 / ARTIC1 PA1 / PWM0 PA2 (HS) / PWM1 PA3 / PWM2 PA4 / PWM3 VSS_3 VDD_3 PA5 (HS) / ARTCLK PA6 (HS) / ARTIC2 PA7 / T8_OCMP2 PB0 /T8_ICAP2 PB1 /T8_OCMP1 PB2 / T8_ICAP1 PB3 / MCO PE0 / AIN12 PE1 / AIN13 PB4 / AIN0 / ICCCLK PE2 / AIN14 PE3 / AIN15
I I/O I/O CT I/O CT I/O CT HS I/O CT I/O CT S S I/O CT HS I/O CT HS I/O CT I/O CT I/O CT I/O CT I/O CT I/O TT I/O TT I/O CT I/O TT I/O TT X X X X X X X X X X X X X X X ei1 X X ei 0 ei0 ei 0 ei1 ei1 ei1 ei1 X X X X X X X RB X RB X RB X RB X RB X e i 1 RB X X X X X X X X X X X X X X X X X X X ei0 ei 0 ei0 ei 0 ei0 X X X X X X X X X X
External clock input or Resonator oscillator inverter input Resonator oscillator inverter output Port A0 Port A1 Port A2 Port A3 Port A4 ART Input Capture 1 ART PWM Output 0 ART PWM Output 1 ART PWM Output 2 ART PWM Output 3
Digital Ground Voltage Digital Main Supply Voltage Port A5 Port A6 Port A7 Port B0 Port B1 Port B2 Port B3 Port E0 Port E1 Port B4 Port E2 Port E3 Port B5 ART External Clock ART Input Capture 2 TIM8 Output Compare 2 TIM8 Input Capture 2 TIM8 Output Compare 1 TIM8 Input Capture 1 Main clock out (fOSC2) ADC Analog Input 12 ADC Analog Input 13 ICC Clock input ADC Analog Input 0
15 10 16 11 17 18 -
19 12 20 21 -
ADC Analog Input 14 ADC Analog Input 15 ICC Data in- ADC Analog put Input 1
22 13 10 PB5 / AIN1 / ICCDATA I/O CT
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Pin n LQFP64 LQFP44 LQFP32 Type Pin Name
Level Output Input
Port Input fl oat wpu ana int
OD
PP
Main function Output (after reset)
Alternate function
23 14 11 24 15 25 16 -
PB6 / AIN2 / T16_OCMP1 VSS_2 VDD_2 PB7 /AIN3 / T16_OCMP2 PC0 / AIN4 / T16_ICAP1
I/O CT S S I/O CT I/O CT
X
X
RB X
X
Port B6
TIM16 Output Compare 1
ADC Analog Input 2
Digital Ground Voltage Digital Main Supply Voltage X X X X X X X X ei2 ei2 RB X RB X X X X X X X X X Port B7 Port C0 Port C1 Port C2 Port E4 Flash programming voltage. Must be tied low in user mode. X X X X X X X X X X X X X X X X X X X X X X2 ) X X X X X Port C3 Port C4 Port E5 Port E6 Port C5 Port C6 Port C7 ADC Analog Input 5 SPI Master In/Slave Out SPI Master Out/Slave In SPI Serial Clock CAN Receive Data Input CAN Transmit Data Output TIM16 Output Compare 2 TIM16 Input Capture 1 ADC Analog Input 3 ADC Analog Input 4
26 17 12 27 18 13
28 19 14 PC1 (HS) / T16_ICAP2 I/O CT HS PC2 (HS) / 29 20 15 T16_EXTCLK 30 21 31 P E4 NC I I/O CT I/O CT I/O TT I/O TT I/O CT I/O CT I/O CT S S I/O CT I/O TT I/O TT I/O TT I/O TT I/O CT I/O CT I/O TT I/O TT I CT I/O TT I/O CT HS I/O CT HS I/O TT
TIM16 Input Capture 2 TIM16 External Clock input
Not Connected
32 22 16 VPP 33 23 17 PC3 / CANRX 34 24 18 PC4 / CANTX 35 P E5 PE6 / AIN5 36 25
37 26 19 PC5 /MISO 38 27 20 PC6 / MOSI 39 28 21 PC7 /SCK 40 41 VSS_1 VDD_1
Digital Ground Voltage Digital Main Supply Voltage X X X X X X X X X X X X X X X X X X X X X X X ei3 X X X X ei3 X X X X X X X X X X X X X X X X X X X X X Port D0 Port E7 Port F0 Port F1 Port F2 Port D1 Port D2 Port F3 Port F4 Top level interrupt input pin Port F5 Port D3 LINSCI2 Serial Clock Output ADC Analog Input 7 ADC Analog Input 8 LINSCI1 Receive Data input LINSCI1 Transmit Data output ADC Analog Input 9 SPI Slave Select ADC Analog Input 6
42 29 22 PD0 / SS/ AIN6 43 44 P E7 P F0 PF1 / AIN7 PF2 / AIN8
45 30 46 31
47 32 23 PD1 / SCI1_RDI 48 33 24 PD2 / SCI1_TDO 49 50 51 PF3 / AIN9 P F4 TLI P F5
52 34
53 35 25 PD3 (HS) / SCI2_SCK
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Pin n LQFP64 LQFP44 LQFP32 Type Pin Name
Level Output Input
Port Input fl oat wpu ana int
OD
PP
Main function Output (after reset) X X Port D4
Alternate function
54 36 26 PD4 / SCI2_RDI 55 37 27 VSSA 56 38 28 VSS_0 5 7 3 9 2 9 VDDA 58 40 30 VDD_0 59 41 31 PD5 / SCI2_TDO 60 42 32 R ESET 61 43 62 44 63 64 PD6 / AIN10 PD7 / AIN11 P F6 P F7
I/O CT S S I S I/O CT I/O CT I/O CT I/O CT I/O TT I/O TT
X
ei3
LINSCI2 Receive Data input
Analog Ground Voltage Digital Ground Voltage Analog Reference Voltage for ADC Digital Main Supply Voltage X X X X Port D5 LINSCI2 Transmit Data output ADC Analog Input 10 ADC Analog Input 11
Top priority non maskable interrupt. X X X X X X ei3 X X X X X X X X X Port D6 Port D7 Port F6 Port F7 ei3 X
Notes: 1. In the interrupt input column, "eiX" defines the associated external interrupt vector. If the weak pull-up column (wpu) is merged with the interrupt column (int), then the I/O configuration is pull-up interrupt input, else the configuration is floating interrupt input. 2. Input mode can be used for general purpose I/O, output mode only for CANTX. 3. OSC1 and OSC2 pins connect a crystal/ceramic resonator, or an external source to the on-chip oscillator; see Section 6 and Section 12.5 "CLOCK AND TIMING CHARACTERISTICS" for more details. 4. On the chip, each I/O port has eight pads. Pads that are not bonded to external pins are in input pull-up configuration after reset. The configuration of these pads must be kept at reset state to avoid added current consumption.
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3 REGISTER AND MEMORY MAP
As shown in Figure 5, the MCU is capable of addressing 64 Kbytes of memories and I/O registers. The available memory locations consist of 128 bytes of register locations, up to 2 Kbytes of RAM and up to 60 Kbytes of user program memory. The RAM space includes up to 256 bytes for the stack from 0100h to 01FFh.The highest address bytes contain the user reset and interrupt vectors. IMPORTANT: Memory locations marked as "Reserved" must never be accessed. Accessing a reseved area can have unpredictable effects on the device.
Figure 5. Memory Map
0000h 007Fh 0080h
HW Registers (see Table 3)
0080h
Short Addressing RAM (zero page)
00FFh 0100h
RAM (2048/1024 bytes)
087Fh 0880h 01FFh 0200h
2 5 6 b y t e s St a c k 16-bit Addressing RAM
047Fh or 087Fh
1000h
60 Kbytes
4000h 8000h
Reserved
0FFFh 1000h
48 Kbytes 32 Kbytes
Program Memory (60K, 48K, 32K, 16K)
FFDFh FFE0h FFFFh
C000h
Interrupt & Reset Vectors (see Table 9)
16 Kbytes
FFDFh
Table 3. Hardware Register Map
Address 0000h 0001h 0002h 0003h 0004h 0005h 0006h 0007h 0008h 0009h 000Ah 000Bh 000Ch 000Dh 000Eh Block Register Label PADR PADDR PAOR PBDR PBDDR PBOR PCDR PCDDR PCOR PDDR PDDDR PDOR PEDR PEDDR PEOR Register Name Port A Data Register Port A Data Direction Register Port A Option Register Port B Data Register Port B Data Direction Register Port B Option Register Port C Data Register Port C Data Direction Register Port C Option Register Port D Data Register Port D Data Direction Register Port D Option Register Port E Data Register Port E Data Direction Register Port E Option Register Reset Status 00h1 ) 00h 00h 00h1 ) 00h 00h 00h1 ) 00h 00h 00h1 ) 00h 00h 00h1 ) 00h 00h Remarks R/W 2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2) R/W2)
Port A
Port B
Port C
Port D
Port E
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Address 000Fh 0010h 0011h 0012h to 0020h 0021h 0022h 0023h 0024h 0025h 0026h 0027h 0028h 0029h 002Ah 002Bh 002Ch 002Dh 002Eh 002Fh 0030h 0031h 0032h 0033h 0034h 0035h 0036h 0037h 0038h 0039h 003Ah 003Bh 003Ch 003Dh 003Eh 003Fh 0040h 0041h 0042h 0043h 0044h 0045h 0046h 0047h
Block
Register Label PFDR PFDDR PFOR
Register Name Port F Data Register Port F Data Direction Register Port F Option Register Reserved Area (15 bytes)
Reset Status 00h1 ) 00h 00h
Remarks R/W2) R/W2) R/W2)
Port F
SPI FLASH
SPID R SPICR SPICSR FCSR ISPR0 ISPR1 ISPR2 ISPR3 EICR0 EICR1 AWUC SR AWUPR SICS R MCCSR WDG C R WDGWR PWM DCR3 PWMDCR2 PWMDCR1 PWMDCR0 PWMCR ARTCSR ARTCAR ARTARR ARTICCSR ARTICR1 ARTICR2 T8CR2 T8CR1 T8CSR T8IC1R T8OC1R T8CTR T8ACTR T8IC2R T8OC2R ADCCSR ADCDRH ADCDRL
SPI Data I/O Register SPI Control Register SPI Control/Status Register Flash Control/Status Register Interrupt Software Priority Register 0 Interrupt Software Priority Register 1 Interrupt Software Priority Register 2 Interrupt Software Priority Register 3 External Interrupt Control Register 0 External Interrupt Control Register 1 Auto Wake up f. Halt Control/Status Register Auto Wake Up From Halt Prescaler System Integrity Control / Status Register Main Clock Control / Status Register Watchdog Control Register Watchdog Window Register Pulse Width Modulator Duty Cycle Register 3 PWM Duty Cycle Register 2 PWM Duty Cycle Register 1 PWM Duty Cycle Register 0 PWM Control register Auto-Reload Timer Control/Status Register Auto-Reload Timer Counter Access Register Auto-Reload Timer Auto-Reload Register ART Input Capture Control/Status Register ART Input Capture Register 1 ART Input Capture register 2 Timer Control Register 2 Timer Control Register 1 Timer Control/Status Register Timer Input Capture 1 Register Timer Output Compare 1 Register Timer Counter Register Timer Alternate Counter Register Timer Input Capture 2 Register Timer Output Compare 2 Register Control/Status Register Data High Register Data Low Register
xxh 0xh 00h 00h FFh FFh FFh FFh 00h 00h 00h FFh 0xh 00h 7Fh 7Fh 00h 00h 00h 00h 00h 00h 00h 00h 00h 00h 00h 00h 00h 00h xxh 00h FCh FCh xxh 00h 00h 00h 00h
R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W Read Only Read Only R/W R/W Read Only Read Only R/W Read Only Read Only Read Only R/W R/W Read Only Read Only
ITC
AW U CKCTRL W WD G
PW M AR T
8-BIT TIMER
ADC
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Address 0048h 0049h 004Ah 004Bh 004Ch 004Dh 004Eh 004Fh 0050h 0051h 0052h 0053h 0054h 0055h 0056h 0057h 0058h 0059h 005Ah 005Bh 005Ch 005Dh 005Eh 005Fh 0060h 0061h 0062h 0063h 0064h 0065h 0066h 0067h
Block
Register Label SCI1ISR SCI1DR SCI1BRR SCI1CR1 SCI1CR2 SCI1CR3 SCI1ERPR SCI1ETPR
Register Name SCI1 Status Register SCI1 Data Register SCI1 Baud Rate Register SCI1 Control Register 1 SCI1 Control Register 2 SCI1Control Register 3 SCI1 Extended Receive Prescaler Register SCI1 Extended Transmit Prescaler Register Reserved Area (1 byte)
Reset Status C0h xxh 00h xxh 00h 00h 00h 00h
Remarks Read Only R/W R/W R/W R/W R/W R/W R/W
LINSCI1 (LIN Master/ Slave)
16-BIT TIMER
T16CR2 T16CR1 T16CSR T16IC1HR T16IC1LR T16OC1HR T16OC1LR T16CHR T16CLR T16ACHR T16ACLR T16IC2HR T16IC2LR T16OC2HR T16OC2LR SCI2SR SCI2DR SCI2BRR SCI2CR1 SCI2CR2 SCI2CR3 SCI2ERPR SCI2ETPR
Timer Control Register 2 Timer Control Register 1 Timer Control/Status Register Timer Input Capture 1 High Register Timer Input Capture 1 Low Register Timer Output Compare 1 High Register Timer Output Compare 1 Low Register Timer Counter High Register Timer Counter Low Register Timer Alternate Counter High Register Timer Alternate Counter Low Register Timer Input Capture 2 High Register Timer Input Capture 2 Low Register Timer Output Compare 2 High Register Timer Output Compare 2 Low Register SCI2 Status Register SCI2 Data Register SCI2 Baud Rate Register SCI2 Control Register 1 SCI2 Control Register 2 SCI2 Control Register 3 SCI2 Extended Receive Prescaler Register SCI2 Extended Transmit Prescaler Register
00h 00h 00h xxh xxh 80h 00h FFh FCh FFh FCh xxh xxh 80h 00h C0h xxh 00h xxh 00h 00h 00h 00h
R/W R/W R/W Read Only Read Only R/W R/W Read Only Read Only Read Only Read Only Read Only Read Only R/W R/W Read Only R/W R/W R/W R/W R/W R/W R/W
LINSCI2 (LIN Master)
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Address 0068h 0069h 006Ah 006Bh 006Ch 006Dh 006Eh 006Fh 0070h 0071h 0072h 0073h 0074h 0075h 0076h 0077h 0078h 0079h 007Ah 007Bh 007Ch 007Dh 007Eh 007Fh
Block
Register Label CMCR CMSR CTSR CTPR CRFR CIER CDGR CPSR
Register Name CAN Master Control Register CAN Master Status Register CAN Transmit Status Register CAN Transmit Priority Register CAN Receive FIFO Register CAN Interrupt Enable Register CAN Diagnosis Register CAN Page Selection Register PAGE REGISTER 0 PAGE REGISTER 1 PAGE REGISTER 2 PAGE REGISTER 3 PAGE REGISTER 4 PAGE REGISTER 5 PAGE REGISTER 6 PAGE REGISTER 7 PAGE REGISTER 8 PAGE REGISTER 9 PAGE REGISTER 10 PAGE REGISTER 11 PAGE REGISTER 12 PAGE REGISTER 13 PAGE REGISTER 14 PAGE REGISTER 15
Reset Status
Remarks R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W
Active CAN
PAGES
Legend: x = undefined, R/W = read/write
Notes: 1. The contents of the I/O port DR registers are readable only in output configuration. In input configuration, the values of the I/O pins are returned instead of the DR register contents. 2. The bits associated with unavailable pins must always keep their reset value.
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4 FLASH PROGRAM MEMORY
4.1 INTRODUCTION The ST7 dual voltage High Density Flash (HDFlash) is a non-volatile memory that can be electrically erased as a single block or by individual sectors and programmed on a Byte-by-Byte basis using an external VPP supply. The HDFlash devices can be programmed and erased off-board (plugged in a programming tool) or on-board using ICP (In-Circuit Programming) or IAP (In-Application Programming). The array matrix organisation allows each sector to be erased and reprogrammed without affecting other sectors. 4.2 MAIN FEATURES
Depending on the overall Flash memory size in the microcontroller device, there are up to three user sectors (see Table 3). Each of these sectors can be erased independently to avoid unnecessary erasing of the whole Flash memory when only a partial erasing is required. The first two sectors have a fixed size of 4 Kbytes (see Figure 6). They are mapped in the upper part of the ST7 addressing space so the reset and interrupt vectors are located in Sector 0 (F000hFFFFh). Table 4. Sectors available in Flash devices
Flash Size (bytes) 4K 8K > 8K Available Sectors Sector 0 Sectors 0,1 Sectors 0,1, 2
3 Flash programming modes: Insertion in a programming tool. In this mode, all sectors including option bytes can be programmed or erased. ICP (In-Circuit Programming). In this mode, all sectors including option bytes can be programmed or erased without removing the device from the application board. IAP (In-Application Programming) In this mode, all sectors except Sector 0, can be programmed or erased without removing the device from the application board and while the application is running. ICT (In-Circuit Testing) for downloading and executing user application test patterns in RAM Read-out protection Register Access Security System (RASS) to prevent accidental programming or erasing
4.3 STRUCTURE The Flash memory is organised in sectors and can be used for both code and data storage. Figure 6. Memory Map and Sector Address
4K
1000h 3FFFh 7FFFh 9FFFh BFFFh D7FFh DFFFh EFFFh FFFFh
4.3.1 Read-out Protection Read-out protection, when selected, provides a protection against Program Memory content extraction and against write access to Flash memory. Even if no protection can be considered as totally unbreakable, the feature provides a very high level of protection for a general purpose microcontroller. In Flash devices, this protection is removed by reprogramming the option. In this case, the entire program memory is first automatically erased and the device can be reprogrammed. Read-out protection selection depends on the device type: In Flash devices it is enabled and removed through the FMP_R bit in the option byte. In ROM devices it is enabled by mask option specified in the Option List.
8K
10K
16K
24K
32K
48K
60K
FLASH MEMORY SIZE
SECTOR 2 2 Kbytes 8 Kbytes 16 Kbytes 24 Kbytes 40 Kbytes 52 Kbytes 4 Kbytes 4 Kbytes SECTOR 1 SECTOR 0
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FLASH PROGRAM MEMORY (Cont'd) 4.4 ICC INTERFACE ICC (In-Circuit Communication) needs a minimum of four and up to six pins to be connected to the programming tool (see Figure 7). These pins are: RESET: device reset VSS: device power supply ground Figure 7. Typical ICC Interface
PROGRAMMING TOOL ICC CONNECTOR ICC Cable APPLICATION BOARD (See Note 3) OPTIONAL (See Note 4) ICC CONNECTOR HE10 CONNECTOR TYPE 9 10 7 8 5 6 3 4 1 2 APPLICATION RESET SOURCE See Note 2 10k APPLICATION POWER SUPPLY CL2 CL1 See Note 1 APPLICATION I/O
ICCCLK: ICC output serial clock pin ICCDATA: ICC input/output serial data pin ICCSEL/VPP: programming voltage OSC1(or OSCIN): main clock input for external source (optional) VDD: application board power supply (see Figure 7, Note 3)
ST7
Notes: 1. If the ICCCLK or ICCDATA pins are only used as outputs in the application, no signal isolation is necessary. As soon as the Programming Tool is plugged to the board, even if an ICC session is not in progress, the ICCCLK and ICCDATA pins are not available for the application. If they are used as inputs by the application, isolation such as a serial resistor has to implemented in case another device forces the signal. Refer to the Programming Tool documentation for recommended resistor values. 2. During the ICC session, the programming tool must control the RESET pin. This can lead to conflicts between the programming tool and the application reset circuit if it drives more than 5mA at high level (push pull output or pull-up resistor<1K). A schottky diode can be used to isolate the application RESET circuit in this case. When using a classical RC network with R > 1K or a reset man-
agement IC with open drain output and pull-up resistor > 1K, no additional components are needed. In all cases the user must ensure that no external reset is generated by the application during the ICC session. 3. The use of Pin 7 of the ICC connector depends on the Programming Tool architecture. This pin must be connected when using most ST Programming Tools (it is used to monitor the application power supply). Please refer to the Programming Tool manual. 4. Pin 9 has to be connected to the OSC1 or OSCIN pin of the ST7 when the clock is not available in the application or if the selected clock option is not programmed in the option byte. ST7 devices with multi-oscillator capability need to have OSC2 grounded in this case.
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ICCSEL/VPP
ICCDATA
RESET
ICCCLK
OSC2
OSC1
VDD
VSS
ST72561
FLASH PROGRAM MEMORY (Cont'd) 4.5 ICP (IN-CIRCUIT PROGRAMMING) To perform ICP the microcontroller must be switched to ICC (In-Circuit Communication) mode by an external controller or programming tool. Depending on the ICP code downloaded in RAM, Flash memory programming can be fully customized (number of bytes to program, program locations, or selection serial communication interface for downloading). When using an STMicroelectronics or third-party programming tool that supports ICP and the specific microcontroller device, the user needs only to implement the ICP hardware interface on the application board (see Figure 7). For more details on the pin locations, refer to the device pinout description. 4.6 IAP (IN-APPLICATION PROGRAMMING) This mode uses a BootLoader program previously stored in Sector 0 by the user (in ICP mode or by plugging the device in a programming tool). This mode is fully controlled by user software. This allows it to be adapted to the user application, (user-defined strategy for entering programming mode, choice of communications protocol used to fetch the data to be stored, etc.). For example, it is possible to download code from the SPI, SCI or other type of serial interface and program it in the Flash. IAP mode can be used to program any of the Flash sectors except Sector 0, which is write/ erase protected to allow recovery in case errors occur during the programming operation. 4.7 RELATED DOCUMENTATION For details on Flash programming and ICC protocol, refer to the ST7 Flash Programming Reference Manual and to the ST7 ICC Protocol Reference Manual. 4.8 REGISTER DESCRIPTION FLASH CONTROL/STATUS REGISTER (FCSR) Read / Write Reset Value: 0000 0000 (00h)
7 0 0 0 0 0 0 0 0 0
This register is reserved for use by Programming Tool software. It controls the Flash programming and erasing operations.
Table 5. Flash Control/Status Register Address and Reset Value
Address (Hex.) 0024h Register Label FC SR Reset Value 7 6 5 4 3 2 1 0
0
0
0
0
0
0
0
0
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5 CENTRAL PROCESSING UNIT
5.1 INTRODUCTION This CPU has a full 8-bit architecture and contains six internal registers allowing efficient 8-bit data manipulation. 5.2 MAIN FEATURES
5.3 CPU REGISTERS The six CPU registers shown in Figure 8 are not present in the memory mapping and are accessed by specific instructions. Accumulator (A) The Accumulator is an 8-bit general purpose register used to hold operands and the results of the arithmetic and logic calculations and to manipulate data. Index Registers (X and Y) These 8-bit registers are used to create effective addresses or as temporary storage areas for data manipulation. (The Cross-Assembler generates a precede instruction (PRE) to indicate that the following instruction refers to the Y register.) The Y register is not affected by the interrupt automatic procedures. Program Counter (PC) The program counter is a 16-bit register containing the address of the next instruction to be executed by the CPU. It is made of two 8-bit registers PCL (Program Counter Low which is the LSB) and PCH (Program Counter High which is the MSB).
Enable executing 63 basic instructions Fast 8-bit by 8-bit multiply 17 main addressing modes (with indirect addressing mode) Two 8-bit index registers 16-bit stack pointer Low power HALT and WAIT modes Priority maskable hardware interrupts Non-maskable software/hardware interrupts
Figure 8. CPU Registers
7 RESET VALUE = XXh 7 RESET VALUE = XXh 7 RESET VALUE = XXh 15 PCH 87 PCL 0 PROGRAM COUNTER RESET VALUE = RESET VECTOR @ FFFEh-FFFFh 7 0 CONDITION CODE REGISTER 1 1 I1 H I0 N Z C RESET VALUE = 1 1 1 X 1 X X X 15 87 0 STACK POINTER RESET VALUE = STACK HIGHER ADDRESS X = Undefined Value 0 Y INDEX REGISTER 0 X INDEX REGISTER 0 ACCUMULATOR
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CENTRAL PROCESSING UNIT (Cont'd) Condition Code Register (CC) Read/Write Reset Value: 111x1xxx
7
1 1 I1 H I0 N Z
Bit 1 = Z Zero. This bit is set and cleared by hardware. This bit indicates that the result of the last arithmetic, logical or data manipulation is zero. 0: The result of the last operation is different from zero. 1: The result of the last operation is zero. This bit is accessed by the JREQ and JRNE test instructions. Bit 0 = C Carry/borrow. This bit is set and cleared by hardware and software. It indicates an overflow or an underflow has occurred during the last arithmetic operation. 0: No overflow or underflow has occurred. 1: An overflow or underflow has occurred. This bit is driven by the SCF and RCF instructions and tested by the JRC and JRNC instructions. It is also affected by the "bit test and branch", shift and rotate instructions. Interrupt Management Bits Bit 5,3 = I1, I0 Interrupt The combination of the I1 and I0 bits gives the current interrupt software priority.
Interrupt Software Priority Level 0 (main) Level 1 Level 2 Level 3 (= interrupt disable) I1 1 0 0 1 I0 0 1 0 1
0 C
The 8-bit Condition Code register contains the interrupt masks and four flags representative of the result of the instruction just executed. This register can also be handled by the PUSH and POP instructions. These bits can be individually tested and/or controlled by specific instructions. Arithmetic Management Bits Bit 4 = H Half carry. This bit is set by hardware when a carry occurs between bits 3 and 4 of the ALU during an ADD or ADC instructions. It is reset by hardware during the same instructions. 0: No half carry has occurred. 1: A half carry has occurred. This bit is tested using the JRH or JRNH instruction. The H bit is useful in BCD arithmetic subroutines. Bit 2 = N Negative. This bit is set and cleared by hardware. It is representative of the result sign of the last arithmetic, logical or data manipulation. It's a copy of the result 7th bit. 0: The result of the last operation is positive or null. 1: The result of the last operation is negative (that is, the most significant bit is a logic 1). This bit is accessed by the JRMI and JRPL instructions.
These two bits are set/cleared by hardware when entering in interrupt. The loaded value is given by the corresponding bits in the interrupt software priority registers (IxSPR). They can be also set/ cleared by software with the RIM, SIM, IRET, HALT, WFI and PUSH/POP instructions. See the interrupt management chapter for more details.
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CENTRAL PROCESSING UNIT (Cont'd) Stack Pointer (SP) Read/Write Reset Value: 01 FFh
15 0 7
SP7 SP6 SP5 SP4 SP3 SP2 SP1
8 0 0 0 0 0 0 1 0 SP0
The Stack Pointer is a 16-bit register which is always pointing to the next free location in the stack. It is then decremented after data has been pushed onto the stack and incremented before data is popped from the stack (see Figure 9). Since the stack is 256 bytes deep, the 8 most significant bits are forced by hardware. Following an MCU Reset, or after a Reset Stack Pointer instruction (RSP), the Stack Pointer contains its reset value (the SP7 to SP0 bits are set) which is the stack higher address. Figure 9. Stack Manipulation Example
CALL Subroutine @ 0100h Interrupt Event P USH Y
The least significant byte of the Stack Pointer (called S) can be directly accessed by a LD instruction. Note: When the lower limit is exceeded, the Stack Pointer wraps around to the stack upper limit, without indicating the stack overflow. The previously stored information is then overwritten and therefore lost. The stack also wraps in case of an underflow. The stack is used to save the return address during a subroutine call and the CPU context during an interrupt. The user may also directly manipulate the stack by means of the PUSH and POP instructions. In the case of an interrupt, the PCL is stored at the first location pointed to by the SP. Then the other registers are stored in the next locations as shown in Figure 9. When an interrupt is received, the SP is decremented and the context is pushed on the stack. On return from interrupt, the SP is incremented and the context is popped from the stack. A subroutine call occupies two locations and an interrupt five locations in the stack area.
PO P Y
IRET
RET or RSP
SP SP CC A X PC H SP PCH @ 01FFh PCL P CL PCH PCL Y CC A X PCH PCL PCH PC L SP CC A X PCH PCL PCH PCL SP PCH PCL SP
Stack Higher Address = 01FFh Stack Lower Address = 0100h
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6 SUPPLY, RESET AND CLOCK MANAGEMENT
The device includes a range of utility features for securing the application in critical situations (for example, in case of a power brown-out), and reducing the number of external components. An overview is shown in Figure 11. For more details, refer to dedicated parametric section. Main features Optional PLL for multiplying the frequency by 2 Reset Sequence Manager (RSM) Multi-Oscillator Clock Management (MO) 4 Crystal/Ceramic resonator oscillators System Integrity Management (SI) Main supply Low voltage detection (LVD) Auxiliary Voltage detector (AVD) with interrupt capability for monitoring the main supply Figure 11. Clock, Reset and Supply Block Diagram
/ 8000 8-BIT TIMER
6.1 PHASE LOCKED LOOP If the clock frequency input to the PLL is in the range 2 to 4 MHz, the PLL can be used to multiply the frequency by two to obtain an fOSC2 of 4 to 8 MHz. The PLL is enabled by option byte. If the PLL is disabled, then fOSC2 = fOSC/2. Caution: The PLL is not recommended for applications where timing accuracy is required. See "PLL Characteristics" on page 228. Figure 10. PLL Block Diagram
PLL x 2
fOSC 0 fOSC2 1
/2
PLL OPTION BIT
OSC2 OSC1
MULTIOSCILLATOR (MO)
fOSC PLL (option)
fOSC2
MAIN CLOCK CONTROLLER WITH REALTIME CLOCK (MCC/RTC) SYSTEM INTEGRITY MANAGEMENT
fCPU
RESET SEQUENCE RESET MANAGER (RSM)
AVD Interrupt Request SICSR AVD AVD LVD 0 F RF IE WDG RF
WATCHDOG TIMER (WDG)
0
0
0
LOW VOLTAGE VSS VDD DETECTOR (LVD)
AUXILIARY VOLTAGE DETECTOR (AVD)
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6.2 MULTI-OSCILLATOR (MO) The main clock of the ST7 can be generated by two different source types coming from the multioscillator block: an external source a crystal or ceramic resonator oscillator Each oscillator is optimized for a given frequency range in terms of consumption and is selectable through the option byte. The associated hardware configuration are shown in Table 6. Refer to the electrical characteristics section for more details. Caution: The OSC1 and/or OSC2 pins must not be left unconnected. For the purposes of Failure Mode and Effect Analysis, it should be noted that if the OSC1 and/or OSC2 pins are left unconnected, the ST7 main oscillator may start and, in this configuration, could generate an fOSC clock frequency in excess of the allowed maximum (> 16 MHz), putting the ST7 in an unsafe/undefined state. The product behavior must therefore be considered undefined when the OSC pins are left unconnected. External Clock Source In external clock mode, a clock signal (square, sinus or triangle) with ~50% duty cycle has to drive the OSC1 pin while the OSC2 pin is tied to ground. Crystal/Ceramic Oscillators This family of oscillators has the advantage of producing a very accurate rate on the main clock of the ST7. The selection within a list of five oscillators with different frequency ranges must be done by option byte in order to reduce consumption (refer to Section 14.1 on page 252 for more details on the frequency ranges). The resonator and the load capacitors must be placed as close as possible to the oscillator pins in order to minimize output distortion and start-up stabilization time. The loading capacitance values must be adjusted according to the selected oscillator. These oscillators are not stopped during the RESET phase to avoid losing time in the oscillator start-up phase. Table 6. ST7 Clock Sources
Hardware Configuration
External Clock
ST7 OS C1 OSC 2
EX TERNAL SO URCE
Crystal/Ceramic Resonators
ST7 OSC 1 OSC2
CL1
LOA D CAPA CITO RS
CL 2
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6.3 RESET SEQUENCE MANAGER (RSM) 6.3.1 Introduction The reset sequence manager includes three RESET sources as shown in Figure 2: External RESET source pulse Internal LVD RESET (Low Voltage Detection) Internal WATCHDOG RESET These sources act on the RESET pin and it is always kept low during the delay phase. The RESET service routine vector is fixed at addresses FFFEh-FFFFh in the ST7 memory map. The basic RESET sequence consists of three phases as shown in Figure 1: Active Phase depending on the RESET source 256 or 4096 CPU clock cycle delay (selected by option byte) RESET vector fetch The 256 or 4096 CPU clock cycle delay allows the oscillator to stabilize and ensures that recovery has taken place from the Reset state. The shorter or longer clock cycle delay should be selected by option byte to correspond to the stabilization time of the external oscillator used in the application. The RESET vector fetch phase duration is two clock cycles. Figure 13. Reset Block Diagram Figure 12. RESET Sequence Phases
RESET
Active Phase INTERNAL RESET 256 or 4096 CLOCK CYCLES FETCH VECTOR
Caution: When the ST7 is unprogrammed or fully erased, the Flash is blank and the RESET vector is not programmed. For this reason, it is recommended to keep the RESET pin in low state until programming mode is entered, in order to avoid unwanted behavior. 6.3.2 Asynchronous External RESET pin The RESET pin is both an input and an open-drain output with integrated RON weak pull-up resistor. This pull-up has no fixed value but varies in accordance with the input voltage. It can be pulled low by external circuitry to reset the device. See Electrical Characteristic section for more details. A RESET signal originating from an external source must have a duration of at least th(RSTL)in in order to be recognized (see Figure 3). This detection is asynchronous and therefore the MCU can enter reset state even in HALT mode.
VDD
RO N
RESET
Filter INTERNAL RESET
PULSE GENERATOR
WATCHDOG RESET LVD RESET
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RESET SEQUENCE MANAGER (Cont'd) The RESET pin is an asynchronous signal which plays a major role in EMS performance. In a noisy environment, it is recommended to follow the guidelines mentioned in the electrical characteristics section. 6.3.3 External Power-On RESET If the LVD is disabled by option byte, to start up the microcontroller correctly, the user must ensure by means of an external reset circuit that the reset signal is held low until VDD is over the minimum level specified for the selected fOSC frequency. A proper reset signal for a slow rising VDD supply can generally be provided by an external RC network connected to the RESET pin. 6.3.4 Internal Low Voltage Detector (LVD) RESET Two different RESET sequences caused by the internal LVD circuitry can be distinguished: Power-On RESET Voltage Drop RESET The device RESET pin acts as an output that is pulled low when VDD < VIT+ (rising edge) or VDD < VIT- (falling edge) as shown in Figure 3. The LVD filters spikes on VDD larger than tg(VDD) to avoid parasitic resets. 6.3.5 Internal Watchdog RESET The RESET sequence generated by a internal Watchdog counter overflow is shown in Figure 3. Starting from the Watchdog counter underflow, the device RESET pin acts as an output that is pulled low during at least tw(RSTL)out.
Figure 14. RESET Sequences VDD
VIT+(LVD) VIT-(LVD)
LVD RESET
EXTERNAL RESET
WATCHDOG RESET
RUN
ACTIVE PHASE
RUN
ACTIVE PHASE
RUN
ACTIVE PHASE
RUN
th(RSTL)in
EXTERNAL RESET SOURCE
tw(RSTL)out
RESET PIN
WATCHDOG RESET WATCHDOG UNDERFLOW INTERNAL RESET (256 or 4096 TCPU) VECTOR FETCH
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6.4 SYSTEM INTEGRITY MANAGEMENT (SI) The System Integrity Management block contains the Low Voltage Detector (LVD) and Auxiliary Voltage Detector (AVD) functions. It is managed by the SICSR register. 6.4.1 Low Voltage Detector (LVD) The Low Voltage Detector function (LVD) generates a static reset when the VDD supply voltage is below a VIT-(LVD) reference value. This means that it secures the power-up as well as the power-down keeping the ST7 in reset. The VIT-(LVD) reference value for a voltage drop is lower than the VIT+(LVD) reference value for poweron in order to avoid a parasitic reset when the MCU starts running and sinks current on the supply (hysteresis). The LVD Reset circuitry generates a reset when VDD is below: VIT+(LVD) when VDD is rising VIT-(LVD) when VDD is falling The LVD function is illustrated in Figure 15. Provided the minimum VDD value (guaranteed for the oscillator frequency) is above VIT-(LVD), the MCU can only be in two modes: under full software control in static safe reset In these conditions, secure operation is always ensured for the application without the need for external reset hardware. During a Low Voltage Detector Reset, the RESET pin is held low, thus permitting the MCU to reset other devices. Notes: The LVD allows the device to be used without any external RESET circuitry. The LVD is an optional function which can be selected by option byte. It is recommended to make sure that the VDD supply voltage rises monotonously when the device is exiting from Reset, to ensure the application functions properly.
Figure 15. Low Voltage Detector vs Reset
VDD
Vhys VIT+(LVD) VIT-(LVD)
RESET
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SYSTEM INTEGRITY MANAGEMENT (Cont'd) 6.4.2 Auxiliary Voltage Detector (AVD) The Voltage Detector function (AVD) is based on an analog comparison between a VIT-(AVD) and VIT+(AVD) reference value and the VDD main supply. The VIT-(AVD) reference value for falling voltage is lower than the VIT+(AVD) reference value for rising voltage in order to avoid parasitic detection (hysteresis). The output of the AVD comparator is directly readable by the application software through a real time status bit (AVDF) in the SICSR register. This bit is read only. Caution: The AVD function is active only if the LVD is enabled through the option byte. 6.4.2.1 Monitoring the VDD Main Supply If the AVD interrupt is enabled, an interrupt is generated when the voltage crosses the VIT+(AVD) or VIT-(AVD) threshold (AVDF bit toggles). In the case of a drop in voltage, the AVD interrupt acts as an early warning, allowing software to shut Figure 16. Using the AVD to Monitor VDD VDD Early Warning Interrupt (Power has dropped, MCU not not yet in reset)
Vh y s t
down safely before the LVD resets the microcontroller. See Figure 16. The interrupt on the rising edge is used to inform the application that the VDD warning state is over. If the voltage rise time trv is less than 256 or 4096 CPU cycles (depending on the reset delay selected by option byte), no AVD interrupt will be generated when VIT+(AVD) is reached. If trv is greater than 256 or 4096 cycles then: If the AVD interrupt is enabled before the VIT+(AVD) threshold is reached, then two AVD interrupts will be received: The first when the AVDIE bit is set and the second when the threshold is reached. If the AVD interrupt is enabled after the VIT+(AVD) threshold is reached, then only one AVD interrupt occurs.
VIT+(AVD) VIT-(AVD) VIT+(LVD) VIT-(LVD)
trv VOLTAGE RISE TIME
AVDF bit AVD INTERRUPT REQUES T IF AVDIE bit = 1
0
1
RESET VALUE
1
0
INTERRUPT PROCESS
INTERRUPT PROCESS
LVD RESET
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SYSTEM INTEGRITY MANAGEMENT (Cont'd) 6.4.3 Low Power Modes
Mode WAIT H ALT Description No effect on SI. AVD interrupts cause the device to exit from Wait mode. The SICSR register is frozen.
6.4.3.1 Interrupts The AVD interrupt event generates an interrupt if the AVDIE bit is set and the interrupt mask in the CC register is reset (RIM instruction).
Interrupt Event AVD event Enable Event Control Flag Bit AVDF AV DIE Exit from Wait Yes Exit from Halt No
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SYSTEM INTEGRITY MANAGEMENT (Cont'd) 6.4.4 Register Description SYSTEM INTEGRITY (SI) CONTROL/STATUS REGISTER (SICSR) Read / Write Reset Value: 000x 000x (00h) Bits 3:1 = Reserved, must be kept cleared.
7 0 AVD IE A VD F LVD RF 0 0 0 0 WDG RF
Bit 7 = Reserved, must be kept cleared. Bit 6 = AVDIE Voltage Detector interrupt enable This bit is set and cleared by software. It enables an interrupt to be generated when the AVDF flag changes (toggles). The pending interrupt information is automatically cleared when software enters the AVD interrupt routine. 0: AVD interrupt disabled 1: AVD interrupt enabled Bit 5 = AVDF Voltage Detector flag This read-only bit is set and cleared by hardware. If the AVDIE bit is set, an interrupt request is generated when the AVDF bit changes value. Refer to Figure 16 and to Section 6.4.2.1 for additional details . 0: VDD over VIT+(AVD) threshold 1: VDD under VIT-(AVD) threshold Bit 4 = LVDRF LVD reset flag This bit indicates that the last Reset was generated by the LVD block. It is set by hardware (LVD reset) and cleared by software (writing zero). See WDGRF flag description for more details. When the LVD is disabled by OPTION BYTE, the LVDRF bit value is undefined.
Bit 0 = WDGRF Watchdog reset flag This bit indicates that the last Reset was generated by the Watchdog peripheral. It is set by hardware (watchdog reset) and cleared by software (writing zero) or an LVD Reset (to ensure a stable cleared state of the WDGRF flag when CPU starts). Combined with the LVDRF flag information, the flag description is given by the following table.
RESET Sources External RESET pin Watchdog LVD LV DRF 0 0 1 WDG R F 0 1 X
Application notes The LVDRF flag is not cleared when another RESET type occurs (external or watchdog), the LVDRF flag remains set to keep trace of the original failure. In this case, a watchdog reset can be detected by software while an external reset can not. CAUTION: When the LVD is not activated with the associated option byte, the WDGRF flag can not be used in the application.
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7 INTERRUPTS
7.1 INTRODUCTION The ST7 enhanced interrupt management provides the following features: Hardware interrupts Software interrupt (TRAP) Nested or concurrent interrupt management with flexible interrupt priority and level management: Up to 4 software programmable nesting levels Up to 16 interrupt vectors fixed by hardware 2 non maskable events: RESET, TRAP 1 maskable Top Level Event: TLI This interrupt management is based on: Bit 5 and bit 3 of the CPU CC register (I1:0), Interrupt software priority registers (ISPRx), Fixed interrupt vector addresses located at the high addresses of the memory map (FFE0h to FFFFh) sorted by hardware priority order. This enhanced interrupt controller guarantees full upward compatibility with the standard (not nested) ST7 interrupt controller. 7.2 MASKING AND PROCESSING FLOW The interrupt masking is managed by the I1 and I0 bits of the CC register and the ISPRx registers which give the interrupt software priority level of Figure 17. Interrupt Processing Flowchart
RESET PENDING INTERRUPT N Y TLI Interrupt has the same or a lower software priority than current one N I1:0 Interrupt has a higher software priority than current one Y
each interrupt vector (see Table 6). The processing flow is shown in Figure 17. When an interrupt request has to be serviced: Normal processing is suspended at the end of the current instruction execution. The PC, X, A and CC registers are saved onto the stack. I1 and I0 bits of CC register are set according to the corresponding values in the ISPRx registers of the serviced interrupt vector. The PC is then loaded with the interrupt vector of the interrupt to service and the first instruction of the interrupt service routine is fetched (refer to "Interrupt Mapping" table for vector addresses). The interrupt service routine should end with the IRET instruction which causes the contents of the saved registers to be recovered from the stack. Note: As a consequence of the IRET instruction, the I1 and I0 bits will be restored from the stack and the program in the previous level will resume. Table 7. Interrupt Software Priority Levels
Interrupt software priority Level 0 (main) Level 1 Level 2 Level 3 (= interrupt disable) Level Low I1 1 0 High 1 I0 0 1 0 1
FETCH NEXT INSTRUCTION
THE INTERRUPT STAYS PENDING
Y
"IRET" N
RESTORE PC, X, A, CC FROM STACK
EXECUTE INSTRUCTION
STACK PC, X, A, CC LOAD I1:0 FROM INTERRUPT SW REG. LOAD PC FROM INTERRUPT VECTOR
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INTERRUPTS (Cont'd) Servicing Pending Interrupts As several interrupts can be pending at the same time, the interrupt to be taken into account is determined by the following two-step process: the highest software priority interrupt is serviced, if several interrupts have the same software priority then the interrupt with the highest hardware priority is serviced first. Figure 18 describes this decision process. Figure 18. Priority Decision Process
PENDING INTERRUPTS
TRAP (Non Maskable Software Interrupt) This software interrupt is serviced when the TRAP instruction is executed. It will be serviced according to the flowchart in Figure 17 as a TLI. Caution: TRAP can be interrupted by a TLI. RESET The RESET source has the highest priority in the ST7. This means that the first current routine has the highest software priority (level 3) and the highest hardware priority. See the RESET chapter for more details.
Same
SOFTWARE PRIORITY
Different
HIGHEST SOFTWARE PRIORITY SERVICED HIGHEST HARDWARE PRIORITY SERVICED
When an interrupt request is not serviced immediately, it is latched and then processed when its software priority combined with the hardware priority becomes the highest one. Note 1: The hardware priority is exclusive while the software one is not. This allows the previous process to succeed with only one interrupt. Note 2: RESET, TRAP and TLI can be considered as having the highest software priority in the decision process. Different Interrupt Vector Sources Two interrupt source types are managed by the ST7 interrupt controller: the non-maskable type (RESET, TRAP) and the maskable type (external or from internal peripherals). Non-Maskable Sources These sources are processed regardless of the state of the I1 and I0 bits of the CC register (see Figure 17). After stacking the PC, X, A and CC registers (except for RESET), the corresponding vector is loaded in the PC register and the I1 and I0 bits of the CC are set to disable interrupts (level 3). These sources allow the processor to exit HALT mode.
Maskable Sources Maskable interrupt vector sources can be serviced if the corresponding interrupt is enabled and if its own interrupt software priority (in ISPRx registers) is higher than the one currently being serviced (I1 and I0 in CC register). If any of these two conditions is false, the interrupt is latched and thus remains pending. TLI (Top Level Hardware Interrupt) This hardware interrupt occurs when a specific edge is detected on the dedicated TLI pin. Caution: A TRAP instruction must not be used in a TLI service routine. External Interrupts External interrupts allow the processor to exit from HALT low power mode. External interrupt sensitivity is software selectable through the External Interrupt Control register (EICR). External interrupt triggered on edge will be latched and the interrupt request automatically cleared upon entering the interrupt service routine. If several input pins of a group connected to the same interrupt line are selected simultaneously, these will be logically ORed. Peripheral Interrupts Usually the peripheral interrupts cause the MCU to exit from HALT mode except those mentioned in the "Interrupt Mapping" table. A peripheral interrupt occurs when a specific flag is set in the peripheral status registers and if the corresponding enable bit is set in the peripheral control register. The general sequence for clearing an interrupt is based on an access to the status register followed by a read or write to an associated register. Note: The clearing sequence resets the internal latch. A pending interrupt (that is, waiting for being serviced) will therefore be lost if the clear sequence is executed.
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INTERRUPTS (Cont'd) 7.3 INTERRUPTS AND LOW POWER MODES All interrupts allow the processor to exit the WAIT low power mode. On the contrary, only external and other specified interrupts allow the processor to exit from the HALT modes (see column "Exit from HALT" in "Interrupt Mapping" table). When several pending interrupts are present while exiting HALT mode, the first one serviced can only be an interrupt with exit from HALT mode capability and it is selected through the same decision process shown in Figure 18. Note: If an interrupt, that is not able to Exit from HALT mode, is pending with the highest priority when exiting HALT mode, this interrupt is serviced after the first one serviced. Figure 19. Concurrent Interrupt Management
SOFTW ARE PRIORITY LEVEL IT2 IT1 IT4 IT3 TLI IT0 I1 I0
7.4 CONCURRENT & NESTED MANAGEMENT The following Figure 19 and Figure 20 show two different interrupt management modes. The first is called concurrent mode and does not allow an interrupt to be interrupted, unlike the nested mode in Figure 20. The interrupt hardware priority is given in this order from the lowest to the highest: MAIN, IT4, IT3, IT2, IT1, IT0, TLI. The software priority is given for each interrupt. Warning: A stack overflow may occur without notifying the software of the failure.
HARDWARE PRIORITY
TLI IT0 IT1 IT2 IT3 RIM IT4 MAIN MAIN IT1
3 3 3 3 3 3 3/0 10
11 11 11 11 11 11
11 / 10 Figure 20. Nested Interrupt Management
SOFTW ARE PRIORITY LEVEL
TLI
IT0
IT2
IT1
IT4
IT3
I1
I0
HARDWARE PRIORITY
TLI IT0 IT1 IT2 IT3 RIM IT4 MAIN IT4 MAIN IT1 IT2
3 3 2 1 3 3 3/0 10
11 11 00 01 11 11
11 / 10
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USED STACK = 20 BY TES
USED STACK = 10 BYTES
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INTERRUPTS (Cont'd) 7.5 INTERRUPT REGISTER DESCRIPTION CPU CC REGISTER INTERRUPT BITS Read / Write Reset Value: 111x 1010 (xAh)
7 1 1 I1 H I0 N Z 0 C ISPR1 I1_7 I0_7 I1_6 I0_6 I1_5 I0_5 I0_9 I1_4 I1_8 I0_4 I0_8
INTERRUPT SOFTWARE PRIORITY REGISTERS (ISPRX) Read/Write (bit 7:4 of ISPR3 are read only) Reset Value: 1111 1111 (FFh)
7 ISPR0 I1_3 I0_3 I1_2 I0_2 I1_1 I0_1 I1_0 0 I0_0
Bit 5, 3 = I1, I0 Software Interrupt Priority These two bits indicate the current interrupt software priority.
Interrupt Software Priority Level 0 (main) Level 1 Level 2 Level 3 (= interrupt disable*) Level Low I1 1 0 High 1 I0 0 1 0 1
ISPR2 ISPR3
I1_11 I0_11 I1_10 I0_10 I1_9 1 1 1 1
I1_13 I0_13 I1_12 I0_12
These two bits are set/cleared by hardware when entering in interrupt. The loaded value is given by the corresponding bits in the interrupt software priority registers (ISPRx). They can be also set/cleared by software with the RIM, SIM, HALT, WFI, IRET and PUSH/POP instructions (see "Interrupt Dedicated Instruction Set" table). *Note: TLI, TRAP and RESET events can interrupt a level 3 program.
These four registers contain the interrupt software priority of each interrupt vector. Each interrupt vector (except RESET and TRAP) has corresponding bits in these registers where its own software priority is stored. This correspondence is shown in the following table.
Vector address FFFBh-FFFAh FFF9h-FFF8h ... FFE1h-FFE0h ISPRx bits I1_0 and I0_0 bits* I1_1 and I0_1 bits ... I1_13 and I0_13 bits
Each I1_x and I0_x bit value in the ISPRx registers has the same meaning as the I1 and I0 bits in the CC register. Level 0 cannot be written (I1_x = 1, I0_x = 0). In this case, the previously stored value is kept (Example: previous = CFh, write = 64h, result = 44h) The RESET, TRAP and TLI vectors have no software priorities. When one is serviced, the I1 and I0 bits of the CC register are both set. *Note: Bits in the ISPRx registers which correspond to the TLI can be read and written but they are not significant in the interrupt process management. Caution: If the I1_x and I0_x bits are modified while the interrupt x is executed the following behavior has to be considered: If the interrupt x is still pending (new interrupt or flag not cleared) and the new software priority is higher than the previous one, the interrupt x is re-entered. Otherwise, the software priority stays unchanged up to the next interrupt request (after the IRET of the interrupt x).
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INTERRUPTS (Cont'd)
Table 8. Dedicated Interrupt Instruction Set
Instruction HALT IRET JRM JRNM POP CC RIM SIM TRAP WFI New Description Entering Halt mode Interrupt routine return Jump if I1:0 = 11 (level 3) Jump if I1:0 <> 11 Pop CC from the Stack Enable interrupt (level 0 set) Disable interrupt (level 3 set) Software trap Wait for interrupt Pop CC, A, X, PC I1:0 = 11 ? I1:0 <> 11 ? Mem => CC Load 10 in I1:0 of CC Load 11 in I1:0 of CC Software NMI I1 1 1 1 1 H I0 0 1 1 0 N Z C Function/Example I1 1 I1 H H I0 0 I0 N Z C N Z C
Note: During the execution of an interrupt routine, the HALT, POPCC, RIM, SIM and WFI instructions change the current software priority up to the next IRET instruction or one of the previously mentioned instructions.
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INTERRUPTS (Cont'd) Table 9. Interrupt Mapping
N Source Block RESE T TRAP 0 1 2 3 4 5 6 7 8 9 10 11 12 13 TLI MC C/RTC ei0/AW UFH ei1/A V D ei2 ei3 CAN CAN S PI TIM E R8 TIMER16 LINSCI2 LINSCI1 PWM ART Reset Software interrupt External top level interrupt Main clock controller time base interrupt External interrupt ei0/ Auto wake-up from Halt External interrupt ei1/Auxiliary Voltage Detector External interrupt ei2 External interrupt ei3 CAN peripheral interrupt - RX CAN peripheral interrupt - TX / ER / SC SPI peripheral interrupts 8-bit TIMER peripheral interrupts 16-bit TIMER peripheral interrupts LINSCI2 Peripheral interrupts LINSCI1 Peripheral interrupts (LIN Master/ Slave) 8-bit PWM ART interrupts Description Register Label N/A EICR M CCSR EICR/ AWU CSR EICR/ SICSR EICR EICR CIER CIER SP ICSR T8_TCR1 TCR 1 SCI2CR1 SCI1CR1 PW MCR Lowest Priority no yes3) yes no no no no4) yes yes2) Highest Priority Priority Order Exit from HALT1 ) yes no yes yes Address Vector FFFEh-FFFFh FFFC h-FFFDh FFFA h-FFFBh FFF8h-FFF9h FFF6h-FFF7h FFF4h-FFF5h FFF2h-FFF3h FFF0h-FFF1h FFEE h-FFEFh FFEC h -FFEDh FFEA h -FFEBh FFE 8h-FFE9h FFE 6h-FFE7h FFE 4h-FFE5h FFE 2h-FFE3h FFE 0h-FFE1h
Notes: 1. Valid for HALT and ACTIVE HALT modes except for the MCC/RTC interrupt source which exits from ACTIVE HALT mode only. 2. Except AVD interrupt 3. Exit from Halt only when a wake-up condition is detected, generating a Status Change interrupt. See Section 10.8.6 on page 160. 4. It is possible to exit from Halt using the external interrupt which is mapped on the RDI pin.
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INTERRUPTS (Cont'd) 7.6 EXTERNAL INTERRUPTS 7.6.1 I/O Port Interrupt Sensitivity The external interrupt sensitivity is controlled by the ISxx bits in the EICR register (Figure 21). This control allows up to four fully independent external interrupt source sensitivities. Each external interrupt source can be generated on four (or five) different events on the pin: Falling edge Rising edge Figure 21. External Interrupt Control Bits
PORT A [7:0] INTERRUPTS PAOR.0 PADDR.0 PA0 EICR IS00 IS01 PA0 PA1 PA2 PA3 PA4 PA5 PA6 PA7
Falling and rising edge Falling edge and low level To guarantee correct functionality, the sensitivity bits in the EICR register can be modified only when the I1 and I0 bits of the CC register are both set to 1 (level 3). This means that interrupts must be disabled before changing sensitivity. The pending interrupts are cleared by writing a different value in the ISx[1:0] of the EICR.
SENSITIVITY CONTROL
ei0 INTERRUPT SOURCE
PORT B [5:0] INTERRUPTS PBOR.0 PBDDR.0 PB0
EICR IS10 IS11
AWUFH Oscillator
/ AWUPR
To Timer Input Capture 1
PB0 PB1 PB2 PB3 PB4 PB5
SENSITIVITY CONTROL
ei1 INTERRUPT SOURCE
PORT C [2:1] INTERRUPTS PCOR.7 PCDDR.7 PC1
EICR IS20 IS21 PC1 PC2 ei2 INTERRUPT SOURCE
SENSITIVITY CONTROL
PORT D [7:6, 4, 1:0] INTERRUPTS PDOR.0 PDDDR.0 PD0
EICR IS30 IS31 PD0 PD1 PD4 PD6 PD7
SENSITIVITY CONTROL
ei3 INTERRUPT SOURCE
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INTERRUPTS (Cont'd) 7.6.2 Register Description EXTERNAL INTERRUPT CONTROL REGISTER 0 (EICR0) Read / Write Reset Value: 0000 0000 (00h)
7 IS31 IS30 IS21 IS20 IS11 IS10 IS01 0 IS00
These 2 bits can be written only when I1 and I0 of the CC register are both set to 1 (level 3). Bits 1:0 = IS0[1:0] ei0 sensitivity The interrupt sensitivity, defined using the IS0[1:0] bits, is applied to the ei0 external interrupts:
I S 0 1 IS00 0 0 1 1 0 1 0 1 External Interrupt Sensitivity Falling edge & low level Rising edge only Falling edge only Rising and falling edge
Bits 7:6 = IS3[1:0] ei3 sensitivity The interrupt sensitivity, defined using the IS3[1:0] bits, is applied to the ei3 external interrupts:
I S 3 1 IS30 0 0 1 1 0 1 0 1 External Interrupt Sensitivity Falling edge & low level Rising edge only Falling edge only Rising and falling edge
These 2 bits can be written only when I1 and I0 of the CC register are both set to 1 (level 3). EXTERNAL INTERUPT CONTROL REGISTER 1 (EICR1) Read / Write Reset Value: 0000 0000 (00h)
7 0 0 0 0 0 0 TLIS 0 TLIE
These 2 bits can be written only when I1 and I0 of the CC register are both set to 1 (level 3). Bits 5:4 = IS2[1:0] ei2 sensitivity The interrupt sensitivity, defined using the IS2[1:0] bits, is applied to the ei2 external interrupts:
I S 2 1 IS20 0 0 1 1 0 1 0 1 External Interrupt Sensitivity Falling edge & low level Rising edge only Falling edge only Rising and falling edge
BIts 7:2 = Reserved Bit 1 = TLIS Top Level Interrupt sensitivity This bit configures the TLI edge sensitivity. It can be set and cleared by software only when TLIE bit is cleared. 0: Falling edge 1: Rising edge Bit 0 = TLIE Top Level Interrupt enable This bit allows to enable or disable the TLI capability on the dedicated pin. It is set and cleared by software. 0: TLI disabled 1: TLI enabled Notes: A parasitic interrupt can be generated when clearing the TLIE bit. In some packages, the TLI pin is not available. In this case, the TLIE bit must be kept low to avoid parasitic TLI interrupts.
These 2 bits can be written only when I1 and I0 of the CC register are both set to 1 (level 3). Bits 3:2 = IS1[1:0] ei1 sensitivity The interrupt sensitivity, defined using the IS1[1:0] bits, is applied to the ei1 external interrupts:
I S 1 1 IS10 0 0 1 1 0 1 0 1 External Interrupt Sensitivity Falling edge & low level Rising edge only Falling edge only Rising and falling edge
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INTERRUPTS (Cont'd) Table 10. Nested Interrupts Register Map and Reset Values
Address (Hex.) 0025h Register Label ISPR0 Reset Value ISPR1 Reset Value ISPR2 Reset Value ISPR3 Reset Value EICR0 Reset Value EICR1 Reset Value 7 6 5 4 3 CLKM I1_1 1 ei3 I1_5 I0_5 1 1 TIM E R 8 I1_9 I0_9 1 1 ART I1_13 I0_13 1 1 IS11 IS10 0 0 0 0 I1_4 1 I0_1 1 1 ei2 I0_4 1 2 1 TLI 1 0
0026h
0027h
ei1 I1_3 I0_3 1 1 CAN TX/ER/SC I1_7 I0_7 1 1 LINSCI 2 I1_11 I0_11 1 1
ei0 I1_2 I0_2 1 1 CAN RX I1_6 I0_6 1 1 TIMER 16 I1_10 I0_10 1 1
0028h 0029h 002Ah
1 IS31 0 0
1 IS30 0 0
1 IS 21 0 0
1 IS20 0 0
SPI I1_8 I0_8 1 1 LINSCI 1 I1_12 I0_12 1 1 IS01 IS00 0 0 TLIS TLIE 0 0
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8 POWER SAVING MODES
8.1 INTRODUCTION To give a large measure of flexibility to the application in terms of power consumption, five main power saving modes are implemented in the ST7 (see Figure 22): Slow Wait (and Slow-Wait) Active Halt Auto Wake-up From Halt (AWUFH) Halt After a RESET the normal operating mode is selected by default (RUN mode). This mode drives the device (CPU and embedded peripherals) by means of a master clock which is based on the main oscillator frequency divided or multiplied by 2 (fOSC2). From RUN mode, the different power saving modes may be selected by setting the relevant register bits or by calling the specific ST7 software instruction whose action depends on the oscillator status. Figure 22. Power Saving Mode Transitions
MCCSR High RUN SLO W WAIT SLOW WA IT AC TIVE HALT AUTO WAKE-UP FROM HALT HALT Low PO WER CONS UMPTION
NEW SLOW FREQUENCY REQUEST NORMAL RUN MODE REQUEST
8.2 SLOW MODE This mode has two targets: To reduce power consumption by decreasing the internal clock in the device, To adapt the internal clock frequency (fCPU) to the available supply voltage. SLOW mode is controlled by three bits in the MCCSR register: the SMS bit which enables or disables Slow mode and two CPx bits which select the internal slow frequency (fCPU). In this mode, the master clock frequency (fOSC2) can be divided by 2, 4, 8 or 16. The CPU and peripherals are clocked at this lower frequency (fCPU). Note: SLOW-WAIT mode is activated by entering WAIT mode while the device is in SLOW mode. Figure 23. SLOW Mode Clock Transitions
fOSC2/2 fCPU fOSC2/4 fOSC2
f OSC2 CP1:0 SMS 00 01
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POWER SAVING MODES (Cont'd) 8.3 WAIT MODE WAIT mode places the MCU in a low power consumption mode by stopping the CPU. This power saving mode is selected by calling the `WFI' instruction. All peripherals remain active. During WAIT mode, the I[1:0] bits of the CC register are forced to `10', to enable all interrupts. All other registers and memory remain unchanged. The MCU remains in WAIT mode until an interrupt or RESET occurs, whereupon the Program Counter branches to the starting address of the interrupt or Reset service routine. The MCU will remain in WAIT mode until a Reset or an Interrupt occurs, causing it to wake up. Refer to Figure 24 Figure 24. WAIT Mode Flow-chart
OSCILLATOR PERIPHERALS CPU I[1:0] BITS ON ON OFF 10
WFI I N S T R U C T I O N
N RESET N INTE RRUPT Y OSCILLATOR PERIPHERALS CPU I[1:0] BITS ON OFF ON 10 Y
256 OR 4096 CPU CLOCK CYCLE DELAY
OSCILLATOR ON PERIPHERALS ON CPU ON I[1:0] BITS XX 1 )
FETCH RESET VECTO R OR SERVICE INTER RUPT
Note: 1. Before servicing an interrupt, the CC register is pushed on the stack. The I[1:0] bits of the CC register are set to the current software priority level of the interrupt routine and recovered when the CC register is popped.
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POWER SAVING MODES (Cont'd) 8.4 HALT MODE The HALT mode is the lowest power consumption mode of the MCU. It is entered by executing the `HALT' instruction when the OIE bit of the Main Clock Controller Status register (MCCSR) is cleared (see Section 10.2 on page 59 for more details on the MCCSR register) and when the AWUEN bit in the AWUCSR register is cleared. The MCU can exit HALT mode on reception of either a specific interrupt (see Table 9, "Interrupt Mapping," on page 34) or a RESET. When exiting HALT mode by means of a RESET or an interrupt, the oscillator is immediately turned on and the 256 or 4096 CPU cycle delay is used to stabilize the oscillator. After the start up delay, the CPU resumes operation by servicing the interrupt or by fetching the reset vector which woke it up (see Figure 26). When entering HALT mode, the I[1:0] bits in the CC register are forced to `10b' to enable interrupts. Therefore, if an interrupt is pending, the MCU wakes up immediately. In HALT mode, the main oscillator is turned off causing all internal processing to be stopped, including the operation of the on-chip peripherals. All peripherals are not clocked except the ones which get their clock supply from another clock generator (such as an external or auxiliary oscillator). The compatibility of Watchdog operation with HALT mode is configured by the "WDGHALT" option bit of the option byte. The HALT instruction when executed while the Watchdog system is enabled, can generate a Watchdog RESET (see Section 10.1 on page 53 for more details). Figure 25. HALT Timing Overview
RUN HA LT 256 OR 4096 CPU CYCLE DELAY R ESET OR INTERR UPT FETC H VECTOR RUN
Figure 26. HALT Mode Flow-chart
H A L T INS T RUCTIO N (M CCSR.OIE = 0) (AW UCSR.AWUE N=0) ENABLE WDGHALT 1) 1 WATCHD OG R ESET OS CILLATOR OFF PERIPHERALS 2) OFF C PU OFF I[1:0] BITS 10 0 W ATCHDOG DISABLE
N RE SET N Y INTERRUPT 3) Y OS CILLATOR ON PERIPHERALS OFF C PU ON I[1:0] BITS XX 4) 256 OR 4096 CPU CLOCK CYCLE D EL AY OS CILLATOR ON PERIPHERALS ON C PU ON I[1:0] BITS XX 4) FE TCH R E SET VE CTOR O R SERVIC E INTERRUP T
HALT INS T RUCTIO N [MCCSR.OIE=0]
Notes: 1. WDGHALT is an option bit. See option byte section for more details. 2. Peripheral clocked with an external clock source can still be active. 3. Only some specific interrupts can exit the MCU from HALT mode (such as external interrupt). Refer to Table 9, "Interrupt Mapping," on page 34 for more details. 4. Before servicing an interrupt, the CC register is pushed on the stack. The I[1:0] bits of the CC register are set to the current software priority level of the interrupt routine and recovered when the CC register is popped.
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POWER SAVING MODES (Cont'd) Halt Mode Recommendations Make sure that an external event is available to wake up the microcontroller from Halt mode. When using an external interrupt to wake up the microcontroller, reinitialize the corresponding I/O as "Input Pull-up with Interrupt" before executing the HALT instruction. The main reason for this is that the I/O may be wrongly configured due to external interference or by an unforeseen logical condition. For the same reason, reinitialize the level sensitiveness of each external interrupt as a precautionary measure. The opcode for the HALT instruction is 0x8E. To avoid an unexpected HALT instruction due to a program counter failure, it is advised to clear all occurrences of the data value 0x8E from memory. For example, avoid defining a constant in ROM with the value 0x8E. As the HALT instruction clears the interrupt mask in the CC register to allow interrupts, the user may choose to clear all pending interrupt bits before executing the HALT instruction. This avoids entering other peripheral interrupt routines after executing the external interrupt routine corresponding to the wake-up event (reset or external interrupt). 8.5 ACTIVE HALT MODE ACTIVE HALT mode is the lowest power consumption mode of the MCU with a real time clock available. It is entered by executing the `HALT' instruction when MCC/RTC interrupt enable flag (OIE bit in MCCSR register) is set and when the AWUEN bit in the AWUCSR register is cleared (See "Register Description" on page 45.)
MCCSR OIE bit 0 1 Power Saving Mode entered when HALT instruction is executed HALT mode ACTIVE HALT mode
The MCU can exit ACTIVE HALT mode on reception of the RTC interrupt and some specific interrupts (see Table 9, "Interrupt Mapping," on page 34) or a RESET. When exiting ACTIVE HALT mode by means of a RESET a 4096 or 256 CPU cycle delay occurs (depending on the option byte). After the start up delay, the CPU resumes operation by servicing the interrupt or by fetching the reset vector which woke it up (see Figure 28). When entering ACTIVE HALT mode, the I[1:0] bits in the CC register are are forced to `10b' to enable interrupts. Therefore, if an interrupt is pending, the MCU wakes up immediately. In ACTIVE HALT mode, only the main oscillator and its associated counter (MCC/RTC) are running to keep a wake-up time base. All other peripherals are not clocked except those which get their clock supply from another clock generator (such as external or auxiliary oscillator). The safeguard against staying locked in ACTIVE HALT mode is provided by the oscillator interrupt. Note: As soon as active halt is enabled, executing a HALT instruction while the Watchdog is active does not generate a RESET. This means that the device cannot spend more than a defined delay in this power saving mode.
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POWER SAVING MODES (Cont'd) Figure 27. ACTIVE HALT Timing Overview
RUN ACTIVE 256 OR 4096 CYCLE HALT DELAY (AFTER RESET) RUN
R ESET OR HA LT INTERR UPT INS T RUCTIO N (Active Halt enabled)
FETC H VECTOR
Figure 28. ACTIVE HALT Mode Flow-chart
H A L T INSTR UCTIO N (MC C SR. O IE=1) (AW UCSR.AWUEN =0) OSCILLATOR ON PERIPHERALS 2) OFF CPU OFF 10 I[1:0] BITS N RESET N INTERRUPT 3) Y OSCILLATOR PERIPHERALS CPU I[1:0] BITS ON OFF ON XX 4 ) Y
Notes: 1. This delay occurs only if the MCU exits ACTIVE HALT mode by means of a RESET. 2. Peripheral clocked with an external clock source can still be active. 3. Only the RTC interrupt and some specific interrupts can exit the MCU from ACTIVE HALT mode (such as external interrupt). Refer to Table 9, "Interrupt Mapping," on page 34 for more details. 4. Before servicing an interrupt, the CC register is pushed on the stack. The I[1:0] bits in the CC register are set to the current software priority level of the interrupt routine and restored when the CC register is popped.
256 OR 4096 CPU CLOCK CY CLE DE LAY OSCILLATOR PERIPHERALS CPU I[1:0] BITS ON ON ON XX 4 )
FETCH RESET VECTO R OR SERVICE INTERRUPT
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POWER SAVING MODES (Cont'd) 8.6 AUTO WAKE-UP FROM HALT MODE Auto Wake-Up From Halt (AWUFH) mode is similar to Halt mode with the addition of an internal RC oscillator for wake-up. Compared to ACTIVE HALT mode, AWUFH has lower power consumption because the main clock is not kept running, but there is no accurate realtime clock available. It is entered by executing the HALT instruction when the AWUEN bit in the AWUCSR register has been set and the OIE bit in the MCCSR register is cleared (see Section 10.2 on page 59 for more details ). Figure 29. AWUFH Mode Block Diagram AWU RC oscillator fAWU_RC to Timer input capture and a 256 or 4096 cycle delay is used to stabilize it. After this start-up delay, the CPU resumes operation by servicing the AWUFH interrupt. The AWU flag and its associated interrupt are cleared by software reading the AWUCSR register. To compensate for any frequency dispersion of the AWU RC oscillator, it can be calibrated by measuring the clock frequency fAWU_RC and then calculating the right prescaler value. Measurement mode is enabled by setting the AWUM bit in the AWUCSR register in Run mode. This connects fAWU_RC to the ICAP1 input of the 16-bit timer, allowing the fAWU_RC to be measured using the main oscillator clock as a reference timebase. Similarities with Halt mode The following AWUFH mode behavior is the same as normal Halt mode: The MCU can exit AWUFH mode by means of any interrupt with exit from Halt capability or a reset (see Section 8.4 "HALT MODE"). When entering AWUFH mode, the I[1:0] bits in the CC register are forced to 10b to enable interrupts. Therefore, if an interrupt is pending, the MCU wakes up immediately. In AWUFH mode, the main oscillator is turned off causing all internal processing to be stopped, including the operation of the on-chip peripherals. None of the peripherals are clocked except those which get their clock supply from another clock generator (such as an external or auxiliary oscillator like the AWU oscillator). The compatibility of Watchdog operation with AWUFH mode is configured by the WDGHALT option bit in the option byte. Depending on this setting, the HALT instruction when executed while the Watchdog system is enabled, can generate a Watchdog RESET.
/64 divider
AWUFH prescaler /1 .. 255
AWUFH interrupt (ei0 source)
As soon as HALT mode is entered, and if the AWUEN bit has been set in the AWUCSR register, the AWU RC oscillator provides a clock signal (fAWU_RC). Its frequency is divided by a fixed divider and a programmable prescaler controlled by the AWUPR register. The output of this prescaler provides the delay time. When the delay has elapsed the AWUF flag is set by hardware and an interrupt wakes up the MCU from Halt mode. At the same time the main oscillator is immediately turned on Figure 30. AWUF Halt Timing Diagram tAWU RUN MODE
fCPU fAWU_RC
HALT MODE
256 or 4096 tCPU
RUN MODE
Clear by software
AWUFH interrupt
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POWER SAVING MODES (Cont'd) Figure 31. AWUFH Mode Flow-chart
H AL T INSTRUCTION (MCCSR.OIE=0) (AWUCSR.AWUEN=1) ENABLE WDGHALT 1) 1 WATCHD OG R ESET AWU RC OSC ON MAIN OSC OFF PERIPHERALS 2) OFF C PU OFF I[1:0] BITS 10 0 W ATCHDOG DISABLE
Notes: 1. WDGHALT is an option bit. See option byte section for more details. 2. Peripheral clocked with an external clock source can still be active. 3. Only an AWUFH interrupt and some specific interrupts can exit the MCU from HALT mode (such as external interrupt). Refer to Table 9, "Interrupt Mapping," on page 34 for more details. 4. Before servicing an interrupt, the CC register is pushed on the stack. The I[1:0] bits of the CC register are set to the current software priority level of the interrupt routine and recovered when the CC register is popped.
N RE SET N Y INTERRUPT 3) Y AWU RC OSC OFF MAIN OSC ON PERIPHER ALS OFF C PU ON I[1:0] BITS XX 4) 256 OR 4096 CPU CLOCK CYCLE D EL AY AWU RC OSC OFF MAIN OSC ON PERIPHER ALS O N C PU ON I[1:0] BITS XX 4) FE TCH RE SET VE CTOR O R SERVIC E INTERRUP T
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POWER SAVING MODES (Cont'd) 8.6.1 Register Description AWUFH CONTROL/STATUS REGISTER (AWUCSR) Read / Write (except bit 2 read only) Reset Value: 0000 0000 (00h)
7 0 0 0 0 0 0 AWU AWU A W U F M EN
0: AWUFH (Auto Wake-Up From Halt) mode disabled 1: AWUFH (Auto Wake-Up From Halt) mode enabled AWUFH PRESCALER REGISTER (AWUPR) Read / Write Reset Value: 1111 1111 (FFh)
7 0
Bits 7:3 = Reserved. Bit 2 = AWUF Auto Wake-Up Flag This bit is set by hardware when the AWU module generates an interrupt and cleared by software on reading AWUCSR. 0: No AWU interrupt occurred 1: AWU interrupt occurred Bit 1 = AWUM Auto Wake-Up Measurement This bit enables the AWU RC oscillator and connects its output to the ICAP1 input of the 16-bit timer. This allows the timer to be used to measure the AWU RC oscillator dispersion and then compensate this dispersion by providing the right value in the AWUPR register. 0: Measurement disabled 1: Measurement enabled Bit 0 = AWUEN Auto Wake-Up From Halt Enabled This bit enables the Auto Wake-Up From Halt feature: once HALT mode is entered, the AWUFH wakes up the microcontroller after a time delay defined by the AWU prescaler value. It is set and cleared by software. Table 11. AWU Register Map and Reset Values
Address (Hex.) 002Bh 002Ch Register Label 7 6 5
A W U A W U A W U A W U A W U A WU A WU A W U P R7 P R6 P R5 PR4 PR3 PR2 PR1 PR0
Bits 7:0 = AWUPR[7:0] Auto Wake-Up Prescaler These 8 bits define the AWUPR Dividing factor (as explained below:
AW UPR[7:0] 00h 01h ... FEh FFh Dividing factor Forbidden (See note) 1 ... 254 255
In AWU mode, the period that the MCU stays in Halt Mode (tAWU in Figure 30) is defined by
t
AWU
1 = 64 × A W U P R × ------------------------- + t RCSTRT f AWURC
This prescaler register can be programmed to modify the time that the MCU stays in Halt mode before waking up automatically. Note: If 00h is written to AWUPR, depending on the product, an interrupt is generated immediately after a HALT instruction or the AWUPR remains unchanged.
4
3
2
1
0
A WU C S R AWUF AWUM AWUEN 0 0 0 0 0 Reset Value 0 0 0 A WU P R A W U P R 7 A W U P R 6 A W U P R 5 A W U P R 4 A W U P R 3 A WU P R 2 A W U P R 1 A W U P R 0 Reset Value 1 1 1 1 1 1 1 1
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9 I/O PORTS
9.1 INTRODUCTION The I/O ports offer different functional modes: transfer of data through digital inputs and outputs and for specific pins: external interrupt generation alternate signal input/output for the on-chip peripherals. An I/O port contains up to 8 pins. Each pin can be programmed independently as digital input (with or without interrupt generation) or digital output. 9.2 FUNCTIONAL DESCRIPTION Each port has two main registers: Data Register (DR) Data Direction Register (DDR) and one optional register: Option Register (OR) Each I/O pin may be programmed using the corresponding register bits in the DDR and OR registers: Bit X corresponding to pin X of the port. The same correspondence is used for the DR register. The following description takes into account the OR register, (for specific ports which do not provide this register refer to the I/O Port Implementation section). The generic I/O block diagram is shown in Figure 32 9.2.1 Input Modes The input configuration is selected by clearing the corresponding DDR register bit. In this case, reading the DR register returns the digital value applied to the external I/O pin. Different input modes can be selected by software through the OR register. Notes: 1. Writing the DR register modifies the latch value but does not affect the pin status. 2. When switching from input to output mode, the DR register has to be written first to drive the correct level on the pin as soon as the port is configured as an output. 3. Do not use read/modify/write instructions (BSET or BRES) to modify the DR register as this might corrupt the DR content for I/Os configured as input. External interrupt function When an I/O is configured as Input with Interrupt, an event on this I/O can generate an external interrupt request to the CPU. Each pin can independently generate an interrupt request. The interrupt sensitivity is independently programmable using the sensitivity bits in the EICR register. Each external interrupt vector is linked to a dedicated group of I/O port pins (see pinout description and interrupt section). If several input pins are selected simultaneously as interrupt sources, these are first detected according to the sensitivity bits in the EICR register and then logically ORed. The external interrupts are hardware interrupts, which means that the request latch (not accessible directly by the application) is automatically cleared when the corresponding interrupt vector is fetched. To clear an unwanted pending interrupt by software, the sensitivity bits in the EICR register must be modified. 9.2.2 Output Modes The output configuration is selected by setting the corresponding DDR register bit. In this case, writing the DR register applies this digital value to the I/O pin through the latch. Then reading the DR register returns the previously stored value. Two different output modes can be selected by software through the OR register: Output push-pull and open-drain. DR register value and output pin status:
DR 0 1 Push-pull VS S VDD Open-drain Vss Floating
9.2.3 Alternate Functions When an on-chip peripheral is configured to use a pin, the alternate function is automatically selected. This alternate function takes priority over the standard I/O programming. When the signal is coming from an on-chip peripheral, the I/O pin is automatically configured in output mode (push-pull or open drain according to the peripheral). When the signal is going to an on-chip peripheral, the I/O pin must be configured in input mode. In this case, the pin state is also digitally readable by addressing the DR register. Note: Input pull-up configuration can cause unexpected value at the input of the alternate peripheral input. When an on-chip peripheral use a pin as input and output, this pin has to be configured in input floating mode.
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I/O PORTS (Cont'd) Figure 32. I/O Port General Block Diagram
ALTERNATE OU TPUT
REGISTER ACCESS
1 0
VDD
P-BUFFER (see table below) PULL-UP (see table below) VDD
ALTERNATE ENA BLE DR
DDR PULL-UP COND ITION If implemented OR SEL N-BUFFER DDR SEL CMO S SCHMITT TRIG GER ANALOG INPUT DIODES (see table below) PAD
OR
EXTERN AL INTERR UPT SOURCE (eix)
Table 12. I/O Port Mode Options
Configuration Mode Input Floating with/without Interrupt Pull-up with/without Interrupt Push-pull Open Drain (logic level) True Open Drain Pull-Up Off On Off NI P-Buffer Off On Off NI On On Diodes to VDD to VSS
O u tput
Legend: NI - not implemented Off - implemented not activated On - implemented and activated
DATA BUS
DR SEL
1 0
ALTERNATE INPUT
NI (see note)
Note: The diode to VDD is not implemented in the true open drain pads. A local protection between the pad and VSS is implemented to protect the device against positive stress.
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I/O PORTS (Cont'd) Table 13. I/O Port Configurations
Hardware Configuration
NOT IMPLEMENTED IN TRUE OPEN DRAIN I/O PORTS VDD RPU PAD PULL-UP CONDITION DR REGISTER ACCESS
DR REGISTER
W DATA BUS R
INPUT 1)
ALTERNATE INPUT EXTERNAL INTERRUPT SOURCE (eix) INTERRUPT CONDITION ANALOG INPUT NOT IMPLEMENTED IN TRUE OPEN DRAIN I/O PORTS
OPEN-DRAIN OUTPUT 2)
VDD RPU
DR REGISTER ACCESS
PAD
DR REGISTER
R/W
DATA BUS
ALTERNATE ENABLE
ALTERNATE OUTPUT
PUSH-PULL OUTPUT 2)
NOT IMPLEMENTED IN TRUE OPEN DRAIN I/O PORTS
VDD RPU
DR REGISTER ACCESS
PAD
DR REGISTER
R/W
DATA BUS
ALTERNATE ENABLE
ALTERNATE OUTPUT
Notes: 1. When the I/O port is in input configuration and the associated alternate function is enabled as an output, reading the DR register will read the alternate function output status. 2. When the I/O port is in output configuration and the associated alternate function is enabled as an input, the alternate function reads the pin status given by the DR register content.
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I/O PORTS (Cont'd) CAUTION: The alternate function must not be activated as long as the pin is configured as input with interrupt, in order to avoid generating spurious interrupts. Analog alternate function When the pin is used as an ADC input, the I/O must be configured as floating input. The analog multiplexer (controlled by the ADC registers) switches the analog voltage present on the selected pin to the common analog rail which is connected to the ADC input. It is recommended not to change the voltage level or loading on any port pin while conversion is in progress. Furthermore it is recommended not to have clocking pins located close to a selected analog pin. WARNING: The analog input voltage level must be within the limits stated in the absolute maximum ratings. 9.3 I/O PORT IMPLEMENTATION The hardware implementation on each I/O port depends on the settings in the DDR and OR registers and specific feature of the I/O port such as ADC Input or true open drain. Switching these I/O ports from one state to another should be done in a sequence that prevents unwanted side effects. Recommended safe transitions are illustrated in Figure 33 on page 49. Other transitions are potentially risky and should be avoided, since they are likely to present unwanted side-effects such as spurious interrupt generation.
Figure 33. Interrupt I/O Port State Transitions
01
INPUT floating/pull-up interrupt
00
INPUT floating (reset state)
10
OUTPUT open-drain
11
OUTPUT push-pull
XX
= DDR, OR
9.4 LOW POWER MODES
Mode WAIT H AL T Description No effect on I/O ports. External interrupts cause the device to exit from WAIT mode. No effect on I/O ports. External interrupts cause the device to exit from HALT mode.
9.5 INTERRUPTS The external interrupt event generates an interrupt if the corresponding configuration is selected with DDR and OR registers and the interrupt mask in the CC register is not active (RIM instruction).
Interrupt Event External interrupt on selected external event Enable Event Control Flag Bit DDRx OR x Exit from Wait Exit from Halt
Yes
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I/O PORTS (Cont'd) 9.6 I/O PORT REGISTER CONFIGURATIONS The I/O port register configurations are summarized as follows. 9.6.1 Standard Ports PB7:6, PC0, PC3, PC7:5, PD3:2, PD5, PE7:0, PF7:0
MODE floating input pull-up input open drain output push-pull output D DR 0 0 1 1 OR 0 1 0 1
PA1,3,5,7; PB1,3,5; PC2; PD1,4,7 (without pull-up)
MODE floating input floating interrupt input open drain output push-pull output D DR 0 0 1 1 OR 0 1 0 1
9.6.3 Pull-up Input Port (CANTX requirement) P C4
MO DE pull-up input
9.6.2 Interrupt Ports PA0,2,4,6; PB0,2,4; PC1; PD0,6 (with pull-up)
MODE floating input pull-up interrupt input open drain output push-pull output D DR 0 0 1 1 OR 0 1 0 1
The PC4 port cannot operate as a general purpose output. The CAN peripheral controls it directly when enabled. Otherwise, PC4 is a pull-up input. If DDR = 1 it is still possible to read the port through the DR register.
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I/O PORTS (Cont'd) Table 14. Port Configuration
Port Pin name
PA0 PA1 PA2 PA3 PA4 PA5 PA6 PA7 PB0 PB1 PB2 PB3 PB4 PB5 PC0 PC1 PC2 PC3 PC4 PC7:5 PD0 PD1 PD3:2 PD4 PD5 PD6 PD7 PE7:0 PF7:0
Input OR = 0 OR = 1
pull-up interrupt (ei0) floating interrupt (ei0) pull-up interrupt (ei0) floating interrupt (ei0) pull-up interrupt (ei0) floating interrupt (ei0) pull-up interrupt (ei0) floating interrupt (ei0) pull-up interrupt (ei1) floating interrupt (ei1) pull-up interrupt (ei1) floating interrupt (ei1) pull-up interrupt (ei1) floating interrupt (ei1) pull-up pull-up interrupt (ei2) floating interrupt (ei2) pull-up pull-up pull-up pull-up interrupt (ei3) floating interrupt (ei3) pull-up floating interrupt (ei3) pull-up pull-up interrupt (ei3) floating interrupt (ei3) pull-up (TTL) pull-up (TTL)
Output OR = 0 OR = 1
Port A
floating
open drain
push-pull
Port B
floating
open drain
push-pull
floating
open drain
push-pull
Port C
floating
controlled by CANTX * open drain push-pull
Port D
floating
open drain
push-pull
Port E Port F
floating (TTL) floating (TTL)
open drain open drain
push-pull push-pull
* Note: When the CANTX alternate function is selected, the I/O port operates in output push-pull mode.
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I/O PORTS (Cont'd) Table 15. I/O Port Register Map and Reset Values
Address (Hex.) Register Label 7 0 6 0 5 0 4 0 3 0 2 0 1 0 0 0
Reset Value of all IO port registers 0000h P ADR 0001h P ADDR 0002h P A OR 0003h P BDR 0004h P BDDR 0005h P B OR 0006h P CDR 0007h P CDDR 0008h P C OR 0009h P DDR 000Ah P DDDR 000Bh P D OR 000Ch P EDR 000Dh P EDDR 000Eh P E OR 000Fh P F DR 0010h P F DDR 0011h P F OR
MSB
LSB
MSB
LSB
MSB
LSB
MSB
LSB
MSB
LSB
MSB
LSB
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10 ON-CHIP PERIPHERALS
10.1 WINDOW WATCHDOG (WWDG) 10.1.1 Introduction The Window Watchdog is used to detect the occurrence of a software fault, usually generated by external interference or by unforeseen logical conditions, which causes the application program to abandon its normal sequence. The Watchdog circuit generates an MCU reset on expiry of a programmed time period, unless the program refreshes the contents of the downcounter before the T6 bit becomes cleared. An MCU reset is also generated if the 7-bit downcounter value (in the control register) is refreshed before the downcounter has reached the window register value. This implies that the counter must be refreshed in a limited window. 10.1.2 Main Features Programmable free-running downcounter Conditional reset Reset (if watchdog activated) when the downcounter value becomes less than 40h Reset (if watchdog activated) if the downFigure 34. Watchdog Block Diagram
RES ET W6 WATCHDOG WINDOW REGISTER (WDGWR) W5 W4 W3 W2 W1 W0
counter is reloaded outside the window (see Figure 4) Hardware/Software Watchdog activation (selectable by option byte) Optional reset on HALT instruction (configurable by option byte) 10.1.3 Functional Description The counter value stored in the WDGCR register (bits T[6:0]), is decremented every 16384 fOSC2 cycles (approx.), and the length of the timeout period can be programmed by the user in 64 increments. If the watchdog is activated (the WDGA bit is set) and when the 7-bit downcounter (T[6:0] bits) rolls over from 40h to 3Fh (T6 becomes cleared), it initiates a reset cycle pulling low the reset pin for typically 30s. If the software reloads the counter while the counter is greater than the value stored in the window register, then a reset is generated.
comparator = 1 when T6:0 > W6:0 CMP Write WDGCR WATCHDOG CONTROL REGISTER (WDGCR) WDGA T6 T5 T4 T3 T2 T1 T0
MCC/RTC fOSC2
DIV 64
6-BIT DOWNCOUNTER (CNT)
WDG PRESCALER DIV 4 12-BIT MCC RTC COUNTER MS B
11 65
LSB
0
TB[1:0] bits (MC C SR Register)
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WINDOW WATCHDOG (Cont'd) The application program must write in the WDGCR register at regular intervals during normal operation to prevent an MCU reset. This operation must occur only when the counter value is lower than the window register value. The value to be stored in the WDGCR register must be between FFh and C0h (see Figure 2): Enabling the watchdog: When Software Watchdog is selected (by option byte), the watchdog is disabled after a reset. It is enabled by setting the WDGA bit in the WDGCR register, then it cannot be disabled again except by a reset. When Hardware Watchdog is selected (by option byte), the watchdog is always active and the WDGA bit is not used. Controlling the downcounter: This downcounter is free-running: It counts down even if the watchdog is disabled. When the watchdog is enabled, the T6 bit must be set to prevent generating an immediate reset. The T[5:0] bits contain the number of increments which represents the time delay before the watchdog produces a reset (see Figure 2. Approximate Timeout Duration). The timing varies
between a minimum and a maximum value due to the unknown status of the prescaler when writing to the WDGCR register (see Figure 3). The window register (WDGWR) contains the high limit of the window: To prevent a reset, the downcounter must be reloaded when its value is lower than the window register value and greater than 3Fh. Figure 4 describes the window watchdog process. Note: The T6 bit can be used to generate a software reset (the WDGA bit is set and the T6 bit is cleared). Watchdog Reset on Halt option If the watchdog is activated and the watchdog reset on halt option is selected, then the HALT instruction will generate a Reset. 10.1.4 Using Halt Mode with the WDG If Halt mode with Watchdog is enabled by option byte (no watchdog reset on HALT instruction), it is recommended before executing the HALT instruction to refresh the WDG counter, to avoid an unexpected WDG reset immediately after waking up the microcontroller.
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WINDOW WATCHDOG (Cont'd) 10.1.5 How to Program the Watchdog Timeout Figure 2 shows the linear relationship between the 6-bit value to be loaded in the Watchdog Counter (CNT) and the resulting timeout duration in milliseconds. This can be used for a quick calculation without taking the timing variations into account. If Figure 35. Approximate Timeout Duration 3F 38 30
more precision is needed, use the formulae in Figure 3. Caution: When writing to the WDGCR register, always write 1 in the T6 bit to avoid generating an immediate reset.
CNT Value (hex.)
28 20 18
10 08 00 1.5 18 34 50 65 82 98 114 128 Watchdog timeout (ms) @ 8 MHz fOSC2
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WINDOW WATCHDOG (Cont'd) Figure 36. Exact Timeout Duration (tmin and tmax) W HE RE : tmin0 = (LSB + 128) x 64 x tOSC2 tmax0 = 16384 x tOSC2 tOSC2 = 125ns if fOSC2 = 8 MHz CNT = Value of T[5:0] bits in the WDGCR register (6 bits) MSB and LSB are values from the table below depending on the timebase selected by the TB[1:0] bits in the MCCSR register
TB1 Bit TB0 Bit (MCCSR Reg.) (MCCSR Reg.) 0 0 0 1 1 0 1 1 Selected MCCSR Timebase 2ms 4ms 10ms 25ms MSB 4 8 20 49 L SB 59 53 35 54
To calculate the minimum Watchdog Timeout (tmin):
S IF C N T < M------B ---- --4
T H E N t m i n = t m i n 0 + 16384 × C N T × t o s c 2
NT NT ELSE t m i n = t m i n 0 + 16384 × C N T 4--C--------- + ( 192 + L S B ) × 64 × 4--C---------- ---- -- MSB MSB
× to s c 2
To calculate the maximum Watchdog Timeout (tmax):
S IF C N T M------B ---- --4
THEN t m a x = t m a x 0 + 16384 × C N T × t o s c 2
NT NT ELSE t m a x = t m a x 0 + 16384 × C N T 4--C--------- + ( 192 + L S B ) × 64 × 4--C---------- ---- -- MSB MSB
× to s c 2
Note: In the above formulae, division results must be rounded down to the next integer value. Example: With 2ms timeout selected in MCCSR register
Value of T[5:0] Bits in WDGCR Register (Hex.) 00 3F Min. Watchdog Timeout (ms) tmin 1.496 128 Max. Watchdog Timeout (ms) tmax 2.048 128.552
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WINDOW WATCHDOG (Cont'd) Figure 37. Window Watchdog Timing Diagram
T[5:0] CNT downcounter
WDGWR
3Fh
Refresh not allowed Refresh Window
time (step = 16384/fOSC2)
T6 bit Reset
10.1.6 Low Power Modes Mode SLOW WAIT Description No effect on Watchdog: The downcounter continues to decrement at normal speed. No effect on Watchdog: The downcounter continues to decrement.
OIE bit in MCCSR register WDGHALT bit in Option Byte No Watchdog reset is generated. The MCU enters Halt mode. The Watchdog counter is decremented once and then stops counting and is no longer able to generate a watchdog reset until the MCU receives an external interrupt or a reset. 0 0 If an interrupt is received (refer to interrupt table mapping to see interrupts which can occur in halt mode), the Watchdog restarts counting after 256 or 4096 CPU clocks. If a reset is generated, the Watchdog is disabled (reset state) unless Hardware Watchdog is selected by option byte. For application recommendations see Section 0.1.8 below. A reset is generated instead of entering halt mode. No reset is generated. The MCU enters Active Halt mode. The Watchdog counter is not decremented. It stop counting. When the MCU receives an oscillator interrupt or external interrupt, the Watchdog restarts counting immediately. When the MCU receives a reset the Watchdog restarts counting after 256 or 4096 CPU clocks.
HALT
0
1
ACTIVE HALT
1
x
10.1.7 Hardware Watchdog Option If Hardware Watchdog is selected by option byte, the watchdog is always active and the WDGA bit in the WDGCR is not used. Refer to the Option Byte description.
10.1.8 Using Halt Mode with the WDG (WDGHALT option) The following recommendation applies if Halt mode is used when the watchdog is enabled. Before executing the HALT instruction, refresh the WDG counter, to avoid an unexpected WDG reset immediately after waking up the microcontroller.
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WINDOW WATCHDOG (Cont'd) 10.1.9 Interrupts None. 10.1.10 Register Description CONTROL REGISTER (WDGCR) Read / Write Reset Value: 0111 1111 (7F h)
7 WDGA T6 T5 T4 T3 T2 T1 0 T0
WINDOW REGISTER (WDGWR) Read/Write Reset Value: 0111 1111 (7Fh)
7 W6 W5 W4 W3 W2 W1 0 W0
Bit 7 = Reserved Bits 6:0 = W[6:0] 7-bit window value These bits contain the window value to be compared to the downcounter.
Bit 7 = WDGA Activation bit. This bit is set by software and only cleared by hardware after a reset. When WDGA = 1, the watchdog can generate a reset. 0: Watchdog disabled 1: Watchdog enabled Note: This bit is not used if the hardware watchdog option is enabled by option byte. Bits 6:0 = T[6:0] 7-bit counter (MSB to LSB). These bits contain the value of the watchdog counter. It is decremented every 16384 fOSC2 cycles (approx.). A reset is produced when it rolls over from 40h to 3Fh (T6 becomes cleared).
Figure 38. Watchdog Timer Register Map and Reset Values
Address (Hex.) 2F 30 Register Label WDG C R Reset Value W D GW R Reset Value 7 W D GA 0 0 6 T6 1 W6 1 5 T5 1 W5 1 4 T4 1 W4 1 3 T3 1 W3 1 2 T2 1 W2 1 1 T1 1 W1 1 0 T0 1 W0 1
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ON-CHIP PERIPHERALS (Cont'd) 10.2 MAIN CLOCK CONTROLLER WITH REAL TIME CLOCK MCC/RTC The Main Clock Controller consists of three different functions: a programmable CPU clock prescaler a clock-out signal to supply external devices a real time clock timer with interrupt capability Each function can be used independently and simultaneously. 10.2.1 Programmable CPU Clock Prescaler The programmable CPU clock prescaler supplies the clock for the ST7 CPU and its internal peripherals. It manages SLOW power saving mode (See Section 8.2 "SLOW MODE" for more details). The prescaler selects the fCPU main clock frequency and is controlled by three bits in the MCCSR register: CP[1:0] and SMS. 10.2.2 Clock-out Capability The clock-out capability is an alternate function of an I/O port pin that outputs a fOSC2 clock to drive external devices. It is controlled by the MCO bit in the MCCSR register. 10.2.3 Real Time Clock Timer (RTC) The counter of the real time clock timer allows an interrupt to be generated based on an accurate real time clock. Four different time bases depending directly on fOSC2 are available. The whole functionality is controlled by 4 bits of the MCCSR register: TB[1:0], OIE and OIF. When the RTC interrupt is enabled (OIE bit set), the ST7 enters ACTIVE HALT mode when the HALT instruction is executed. See Section 8.5 "ACTIVE HALT MODE" for more details.
Figure 39. Main Clock Controller (MCC/RTC) Block Diagram
fOSC2
MCO
RTC COUNTER
TO WATCHDOG TIMER
MCO CP1 CP0 SMS TB1 TB0 OIE MCCSR
OIF MCC/RTC INTERRUPT
DIV 2, 4, 8, 16
fCPU
CPU CLOCK TO CPU AND PERIPHERALS
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MAIN CLOCK CONTROLLER WITH REAL TIME CLOCK (Cont'd) 10.2.4 Low Power Modes Bits 6:5 = CP[1:0] CPU clock prescaler Mode Description These bits select the CPU clock prescaler which is No effect on MCC/RTC peripheral. applied in the different slow modes. Their action is WAIT MCC/RTC interrupt cause the device to conditioned by the setting of the SMS bit. These exit from WAIT mode. two bits are set and cleared by software
No effect on MCC/RTC counter (OIE bit is set), the registers are frozen. ACTIVE HALT MCC/RTC interrupt cause the device to exit from ACTIVE HALT mode. MCC/RTC counter and registers are froH ALT zen. and MCC/RTC operation resumes when the AWUF HALT MCU is woken up by an interrupt with "exit from HALT" capability. fCPU in SLOW mode fOSC2 / 2 fOSC2 / 4 fOSC2/ 8 fOSC2 / 16 CP1 0 0 1 1 CP0 0 1 0 1
10.2.5 Interrupts The MCC/RTC interrupt event generates an interrupt if the OIE bit of the MCCSR register is set and the interrupt mask in the CC register is not active (RIM instruction).
Interrupt Event Time base overflow event Enable Event Control Flag Bit OIF OIE Exit from Wait Yes Exit from Halt No1 )
Bit 4 = SMS Slow mode select This bit is set and cleared by software. 0: Normal mode. fCPU = fOSC2 1: Slow mode. fCPU is given by CP1, CP0 See Section 8.2 "SLOW MODE" and Section 10.2 "MAIN CLOCK CONTROLLER WITH REAL TIME CLOCK MCC/RTC" for more details. Bits 3:2 = TB[1:0] Time base control These bits select the programmable divider time base. They are set and cleared by software.
Time Base Counter Prescaler f OSC2 =4 MHz fOSC2=8 MHz 16000 32000 80000 20 0 0 4ms 8ms 20ms 50ms 2ms 4ms 10m s 25m s TB1 0 0 1 1 TB0 0 1 0 1
Note: The MCC/RTC interrupt wakes up the MCU from ACTIVE HALT mode, not from HALT or AWUF HALT mode. 10.2.6 Register Description MCC CONTROL/STATUS REGISTER (MCCSR) Read / Write Reset Value: 0000 0000 (00h)
7 MCO CP1 CP0 SM S TB1 TB0 OIE 0 OIF
A modification of the time base is taken into account at the end of the current period (previously set) to avoid an unwanted time shift. This allows to use this time base as a real time clock. Bit 1 = OIE Oscillator interrupt enable This bit set and cleared by software. 0: Oscillator interrupt disabled 1: Oscillator interrupt enabled This interrupt can be used to exit from ACTIVE HALT mode. When this bit is set, calling the ST7 software HALT instruction enters the ACTIVE HALT power saving mode.
Bit 7 = MCO Main clock out selection This bit enables the MCO alternate function on the corresponding I/O port. It is set and cleared by software. 0: MCO alternate function disabled (I/O pin free for general-purpose I/O) 1: MCO alternate function enabled (fOSC2 on I/O port)
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MAIN CLOCK CONTROLLER WITH REAL TIME CLOCK (Cont'd) Bit 0 = OIF Oscillator interrupt flag This bit is set by hardware and cleared by software reading the CSR register. It indicates when set that the main oscillator has reached the selected elapsed time (TB1:0). 0: Timeout not reached 1: Timeout reached CAUTION: The BRES and BSET instructions must not be used on the MCCSR register to avoid unintentionally clearing the OIF bit.
Table 16. Main Clock Controller Register Map and Reset Values
Address (Hex.) 002Dh 002Eh Register Label SICSR Reset Value M CCSR Reset Value 7 0 MC O 0 6 AVDIE CP1 0 5 AVDF CP0 0 4 LV DRF SM S 0 3 0 TB1 0 2 1 0 WDG R F x OIF 0
0 TB0 0
0 OIE 0
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ON-CHIP PERIPHERALS (Cont'd) 10.3 PWM AUTO-RELOAD TIMER (ART) 10.3.1 Introduction The Pulse Width Modulated Auto-Reload Timer on-chip peripheral consists of an 8-bit auto reload counter with compare/capture capabilities and of a 7-bit prescaler clock source. These resources allow five possible operating modes: Generation of up to four independent PWM signals Figure 40. PWM Auto-Reload Timer Block Diagram
PWMCR OEx OPx OCRx REGISTER LOAD PWMx PORT ALTERNATE FUNCTION POLARITY CONTROL COMPARE DCRx REGISTER
Output compare and Time base interrupt Up to two input capture functions External event detector Up to two external interrupt sources The three first modes can be used together with a single counter frequency. The timer can be used to wake up the MCU from WAIT and HALT modes.
ARR REGISTER
8-BIT COUNTER (CAR REGISTER)
LOAD
ARTICx
INPUT CAPTURE CONTROL
LOAD
ICRx REGISTER
ICSx
ICIEx
ICFx
ICCSR
ARTCLK
fEXT fCPU fCOUNTER
ICx INTERRUPT
MUX f INPUT
PROGRAMMABLE PRESCALER
EXCL
CC2
CC1
CC0
TCE
FCRL
OIE
OVF
ARTCSR
OVF INTERRUPT
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PWM AUTO-RELOAD TIMER (Cont'd) 10.3.2 Functional Description Counter The free running 8-bit counter is fed by the output of the prescaler, and is incremented on every rising edge of the clock signal. It is possible to read or write the contents of the counter on the fly by reading or writing the Counter Access register (ARTCAR). When a counter overflow occurs, the counter is automatically reloaded with the contents of the ARTARR register (the prescaler is not affected). Counter clock and prescaler The counter clock frequency is given by: fCOUNTER = fINPUT / 2CC[2:0] The timer counter's input clock (fINPUT) feeds the 7-bit programmable prescaler, which selects one of the eight available taps of the prescaler, as defined by CC[2:0] bits in the Control/Status Register (ARTCSR). Thus the division factor of the prescaler can be set to 2n (where n = 0, 1,..7). This fINPUT frequency source is selected through the EXCL bit of the ARTCSR register and can be either the fCPU or an external input frequency fEXT. The clock input to the counter is enabled by the TCE (Timer Counter Enable) bit in the ARTCSR register. When TCE is reset, the counter is stopped and the prescaler and counter contents are frozen. When TCE is set, the counter runs at the rate of the selected clock source. Figure 41. Output Compare Control
fCOUNTER ARTARR=FDh COUNTER FDh F Eh FFh FDh FEh FFh FDh F Eh FFh
Counter and Prescaler Initialization After RESET, the counter and the prescaler are cleared and fINPUT = fCPU. The counter can be initialized by: Writing to the ARTARR register and then setting the FCRL (Force Counter Re-Load) and the TCE (Timer Counter Enable) bits in the ARTCSR register. Writing to the ARTCAR counter access register, In both cases the 7-bit prescaler is also cleared, whereupon counting will start from a known value. Direct access to the prescaler is not possible. Output compare control The timer compare function is based on four different comparisons with the counter (one for each PWMx output). Each comparison is made between the counter value and an output compare register (OCRx) value. This OCRx register can not be accessed directly, it is loaded from the duty cycle register (PWMDCRx) at each overflow of the counter. This double buffering method avoids glitch generation when changing the duty cycle on the fly.
OCRx
FDh
F Eh
PWMDCRx
FDh
F Eh
PWMx
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PWM AUTO-RELOAD TIMER (Cont'd) Independent PWM signal generation This mode allows up to four Pulse Width Modulated signals to be generated on the PWMx output pins with minimum core processing overhead. This function is stopped during HALT mode. Each PWMx output signal can be selected independently using the corresponding OEx bit in the PWM Control register (PWMCR). When this bit is set, the corresponding I/O pin is configured as output push-pull alternate function. The PWM signals all have the same frequency which is controlled by the counter period and the ARTARR register value. fPWM = fCOUNTER / (256 - ARTARR) When a counter overflow occurs, the PWMx pin level is changed depending on the corresponding OPx (output polarity) bit in the PWMCR register. Figure 42. PWM Auto-reload Timer Function
255 DUTY CYCLE R EGIST ER (PWMDCRx)
When the counter reaches the value contained in one of the output compare register (OCRx) the corresponding PWMx pin level is restored. It should be noted that the reload values will also affect the value and the resolution of the duty cycle of the PWM output signal. To obtain a signal on a PWMx pin, the contents of the OCRx register must be greater than the contents of the ARTARR regis ter. The maximum available resolution for the PWMx duty cycle is: Resolution = 1 / (256 - ARTARR) Note: To get the maximum resolution (1/256), the ARTARR register must be 0. With this maximum resolution, 0% and 100% can be obtained by changing the polarity.
COUNTER
AUTO-RELOAD R EGIST ER (ARTARR) 000
t
PWMx OUTPUT
WITH OEx=1 AND OPx=0 WITH OEx=1 AND OPx=1
Figure 43. PWM Signal from 0% to 100% Duty Cycle
fCOUNTER ARTARR=FDh COUNTER FDh FEh FFh FDh F Eh FFh FDh FEh
OCRx=FCh PWMx OUTPUT WITH OEx=1 AND OPx=0 OCRx=FDh OCRx=FEh OCRx=FFh
t
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PWM AUTO-RELOAD TIMER (Cont'd) Output compare and Time base interrupt On overflow, the OVF flag of the ARTCSR register is set and an overflow interrupt request is generated if the overflow interrupt enable bit, OIE, in the ARTCSR register, is set. The OVF flag must be reset by the user software. This interrupt can be used as a time base in the application. External clock and event detector mode Using the fEXT external prescaler input clock, the auto-reload timer can be used as an external clock event detector. In this mode, the ARTARR register is used to select the nEVENT number of events to be counted before setting the OVF flag. nEVENT = 256 - ARTARR Caution: The external clock function is not available in HALT mode. If HALT mode is used in the application, prior to executing the HALT instruction, the counter must be disabled by clearing the TCE bit in the ARTCSR register to avoid spurious counter increments.
Figure 44. External Event Detector Example (3 counts)
fEXT=fCOUNTER ARTARR=FDh
COUNTER
FDh
FEh
FFh
FDh
F Eh
FFh
FDh
OVF
ARTCSR READ INTERRUPT IF OIE=1 INTERRUPT IF OIE=1
ARTCSR READ
t
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PWM AUTO-RELOAD TIMER (Cont'd) Input Capture Function Input Capture mode allows the measurement of external signal pulse widths through ARTICRx registers. Each input capture can generate an interrupt independently on a selected input signal transition. This event is flagged by a set of the corresponding CFx bits of the Input Capture Control/Status register (ARTICCSR). These input capture interrupts are enabled through the CIEx bits of the ARTICCSR register. The active transition (falling or rising edge) is software programmable through the CSx bits of the ARTICCSR register. The read only input capture registers (ARTICRx) are used to latch the auto-reload counter value when a transition is detected on the ARTICx pin (CFx bit set in ARTICCSR register). After fetching the interrupt vector, the CFx flags can be read to identify the interrupt source. Note: After a capture detection, data transfer in the ARTICRx register is inhibited until the next read (clearing the CFx bit). The timer interrupt remains pending while the CFx flag is set when the interrupt is enabled (CIEx bit set). This means, the ARTICRx register has to be read at each capture event to clear the CFx flag. The timing resolution is given by auto-reload counter cycle time (1/fCOUNTER). Note: During HALT mode, input capture is inhibited (the ARTICRx is never reloaded) and only the external interrupt capability can be used. Note: The ARTICx signal is synchronized on CPU clock. It takes two rising edges until ARTICRx is latched with the counter value. Depending on the prescaler value and the time when the ICAP event occurs, the value loaded in the ARTICRx register may be different. If the counter is clocked with the CPU clock, the value latched in ARTICRx is always the next counter value after the event on ARTICx occurred (Figure 45). If the counter clock is prescaled, it depends on the position of the ARTICx event within the counter cycle (Figure 46).
Figure 45. Input Capture Timing Diagram, fCOUNTER = fCPU
fCPU
fCOUNTER
COUNTER
01h
02h
03h
04h
05h
06h
07h INTERRUPT
ART I Cx PIN ICAP SAMPLED CFx FLAG xxh ICAP SAMPLED
05h t
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PWM AUTO-RELOAD TIMER (Cont'd) Figure 46. input Capture Timing Diagram, fCOUNTER = fCPU / 4
fCPU
fCOUNTER
COUNTER
03h
04h
05h
A R T IC x P I N ICAP SAMPLED CFx FLAG xxh ICR x R E GIST E R 04h
INTERRUPT
t
fCPU
fCOUNTER
COUNTER
03h
04h
05h
A R T IC x P I N ICAP SAMPLED CFx FLAG xxh ICR x R E GIST E R
INTERRUPT
05h t
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External Interrupt Capability This mode allows the Input capture capabilities to be used as external interrupt sources. The interrupts are generated on the edge of the ARTICx signal. The edge sensitivity of the external interrupts is programmable (CSx bit of ARTICCSR register) and they are independently enabled through CIEx bits of the ARTICCSR register. After fetching the interrupt vector, the CFx flags can be read to identify the interrupt source. During HALT mode, the external interrupts can be used to wake up the micro (if the CIEx bit is set). In
this case, the interrupt synchronization is done directly on the ARTICx pin edge (Figure 47). Figure 47. ART External Interrupt in Halt Mode
ART I Cx PIN CFx FLAG INTERRUPT t
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ON-CHIP PERIPHERALS (Cont'd) 10.3.3 Register Description CONTROL / STATUS REGISTER (ARTCSR) Read / Write Reset Value: 0000 0000 (00h)
7 EXCL CC2 CC1 CC0 TCE FCRL OIE 0 OVF 7 0 CA6 CA5 CA4 CA3 CA2 CA1 CA0
0: New transition not yet reached 1: Transition reached COUNTER ACCESS REGISTER (ARTCAR) Read / Write Reset Value: 0000 0000 (00h)
Bit 7 = EXCL External Clock This bit is set and cleared by software. It selects the input clock for the 7-bit prescaler. 0: CPU clock. 1: External clock. Bit 6:4 = CC[2:0] Counter Clock Control These bits are set and cleared by software. They determine the prescaler division ratio from fINPUT.
fCOUNTER fINPUT fINPUT / 2 fINPUT / 4 fINPUT / 8 fINPUT / 16 fINPUT / 32 fINPUT / 64 fINPUT / 128 With fINPUT=8 MHz CC2 CC1 CC0 8 MHz 4 MHz 2 MHz 1 MHz 500 kHz 250 kHz 125 kHz 62.5 kHz 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1
CA7
Bit 7:0 = CA[7:0] Counter Access Data These bits can be set and cleared either by hardware or by software. The ARTCAR register is used to read or write the auto-reload counter "on the fly" (while it is counting).
AUTO-RELOAD REGISTER (ARTARR) Read / Write Reset Value: 0000 0000 (00h)
7 AR7 AR6 AR5 AR4 AR3 AR2 AR1 0 AR0
Bit 3 = TCE Timer Counter Enable This bit is set and cleared by software. It puts the timer in the lowest power consumption mode. 0: Counter stopped (prescaler and counter frozen). 1: Counter running. Bit 2 = FCRL Force Counter Re-Load This bit is write-only and any attempt to read it will yield a logical zero. When set, it causes the contents of ARTARR register to be loaded into the counter, and the content of the prescaler register to be cleared in order to initialize the timer before starting to count. Bit 1 = OIE Overflow Interrupt Enable This bit is set and cleared by software. It allows to enable/disable the interrupt which is generated when the OVF bit is set. 0: Overflow Interrupt disable. 1: Overflow Interrupt enable. Bit 0 = OVF Overflow Flag This bit is set by hardware and cleared by software reading the ARTCSR register. It indicates the transition of the counter from FFh to the ARTARR value.
Bit 7:0 = AR[7:0] Counter Auto-Reload Data These bits are set and cleared by software. They are used to hold the auto-reload value which is automatically loaded in the counter when an overflow occurs. At the same time, the PWM output levels are changed according to the corresponding OPx bit in the PWMCR register. This register has two PWM management functions: Adjusting the PWM frequency Setting the PWM duty cycle resolution PWM Frequency vs Resolution:
ARTA RR value 0 [ 0..127 ] [ 128..191 ] [ 192..223 ] [ 224..239 ] Resolution Min 8-bit > 7-bit > 6-bit > 5-bit > 4-bit ~0.244 kHz ~0.244 kHz ~0.488 kHz ~0.977 kHz ~1.953 kHz fPWM Max 31.25 kHz 62.5 kHz 125 kHz 250 kHz 500 kHz
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ON-CHIP PERIPHERALS (Cont'd) PWM CONTROL REGISTER (PWMCR) Read / Write Reset Value: 0000 0000 (00h)
7 OE3 OE2 OE1 OE0 OP3 OP2 OP1 0 OP0
DUTY CYCLE REGISTERS (PWMDCRx) Read / Write Reset Value: 0000 0000 (00h)
7 DC7 DC6 DC5 DC4 DC3 DC2 DC1 0 DC0
Bit 7:4 = OE[3:0] PWM Output Enable These bits are set and cleared by software. They enable or disable the PWM output channels independently acting on the corresponding I/O pin. 0: PWM output disabled. 1: PWM output enabled. Bit 3:0 = OP[3:0] PWM Output Polarity These bits are set and cleared by software. They independently select the polarity of the four PWM output signals.
PWMx output level OPx Counter <= OCRx 1 0 Counter > OCRx 0 1 0 1
Bit 7:0 = DC[7:0] Duty Cycle Data These bits are set and cleared by software. A PWMDCRx register is associated with the OCRx register of each PWM channel to determine the second edge location of the PWM signal (the first edge location is common to all channels and given by the ARTARR register). These PWMDCR registers allow the duty cycle to be set independently for each PWM channel.
Note: When an OPx bit is modified, the PWMx output signal polarity is immediately reversed.
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ON-CHIP PERIPHERALS (Cont'd) INPUT CAPTURE CONTROL / STATUS REGISTER (ARTICCSR) Read / Write Reset Value: 0000 0000 (00h)
7 0 0 CS2 CS1 CIE2 CIE1 CF2 0 IC7 CF1 IC6 IC5 IC4 IC3 IC2 IC1 IC0
INPUT CAPTURE REGISTERS (ARTICRx) Read only Reset Value: 0000 0000 (00h)
7 0
Bit 7:6 = Reserved, always read as 0. Bit 5:4 = CS[2:1] Capture Sensitivity These bits are set and cleared by software. They determine the trigger event polarity on the corresponding input capture channel. 0: Falling edge triggers capture on channel x. 1: Rising edge triggers capture on channel x. Bit 3:2 = CIE[2:1] Capture Interrupt Enable These bits are set and cleared by software. They enable or disable the Input capture channel interrupts independently. 0: Input capture channel x interrupt disabled. 1: Input capture channel x interrupt enabled. Bit 1:0 = CF[2:1] Capture Flag These bits are set by hardware and cleared by software reading the corresponding ARTICRx register. Each CFx bit indicates that an input capture x has occurred. 0: No input capture on channel x. 1: An input capture has occurred on channel x.
Bit 7:0 = IC[7:0] Input Capture Data These read only bits are set and cleared by hardware. An ARTICRx register contains the 8-bit auto-reload counter value transferred by the input capture channel x event.
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PWM AUTO-RELOAD TIMER (Cont'd) Table 17. PWM Auto-Reload Timer Register Map and Reset Values
Address (Hex.) 0031h Register Label P WM D C R 3 Reset Value P WM D C R 2 Reset Value P WM D C R 1 Reset Value P WM D C R 0 Reset Value P WM C R Reset Value A RT CSR Reset Value A RTCAR Reset Value A RTARR Reset Value A R TICCS R Reset Value A R TICR1 Reset Value A R TICR2 Reset Value 0 IC7 0 IC7 0 0 IC6 0 IC6 0 7 D C7 0 D C7 0 D C7 0 D C7 0 O E3 0 EXCL 0 C A7 0 A R7 0 6 DC6 0 DC6 0 DC6 0 DC6 0 OE2 0 CC2 0 CA6 0 AR6 0 5 DC5 0 DC5 0 DC5 0 DC5 0 OE1 0 CC1 0 CA5 0 AR5 0 CE2 0 IC5 0 IC5 0 4 DC4 0 DC4 0 DC4 0 DC4 0 O E0 0 CC0 0 CA4 0 AR4 0 CE1 0 IC4 0 IC4 0 3 DC3 0 DC3 0 DC3 0 DC3 0 OP3 0 TCE 0 CA3 0 AR3 0 CS2 0 IC3 0 IC3 0 2 DC 2 0 DC 2 0 DC 2 0 DC 2 0 OP 2 0 FCRL 0 CA 2 0 AR 2 0 CS 1 0 IC2 0 IC2 0 1 DC1 0 DC1 0 DC1 0 DC1 0 OP1 0 RIE 0 CA1 0 AR1 0 CF2 0 IC1 0 IC1 0 0 DC0 0 DC0 0 DC0 0 DC0 0 OP0 0 OVF 0 CA0 0 AR0 0 CF1 0 IC0 0 IC0 0
0032h
0033h
0034h
0035h
0036h
0037h
0038h
0039h
003Ah
003Bh
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10.4 16-BIT TIMER 10.4.1 Introduction The timer consists of a 16-bit free-running counter driven by a programmable prescaler. It may be used for a variety of purposes, including pulse length measurement of up to two input signals (input capture) or generation of up to two output waveforms (output compare and PWM). Pulse lengths and waveform periods can be modulated from a few microseconds to several milliseconds using the timer prescaler and the CPU clock prescaler. Some ST7 devices have two on-chip 16-bit timers. They are completely independent, and do not share any resources. They are synchronized after a MCU reset as long as the timer clock frequencies are not modified. This description covers one or two 16-bit timers. In ST7 devices with two timers, register names are prefixed with TA (Timer A) or TB (Timer B). 10.4.2 Main Features Programmable prescaler: fCPU divided by 2, 4 or 8 Overflow status flag and maskable interrupt External clock input (must be at least four times slower than the CPU clock speed) with the choice of active edge 1 or 2 Output Compare functions each with: 2 dedicated 16-bit registers 2 dedicated programmable signals 2 dedicated status flags 1 dedicated maskable interrupt 1 or 2 Input Capture functions each with: 2 dedicated 16-bit registers 2 dedicated active edge selection signals 2 dedicated status flags 1 dedicated maskable interrupt Pulse width modulation mode (PWM) One Pulse mode Reduced Power Mode 5 alternate functions on I/O ports (ICAP1, ICAP2, OCMP1, OCMP2, EXTCLK)* The Block Diagram is shown in Figure 48. *Note: Some timer pins may not be available (not bonded) in some ST7 devices. Refer to the device pin out description. When reading an input signal on a non-bonded pin, the value will always be `1'. 10.4.3 Functional Description 10.4.3.1 Counter The main block of the Programmable Timer is a 16-bit free running upcounter and its associated 16-bit registers. The 16-bit registers are made up of two 8-bit registers called high and low. Counter Register (CR): Counter High Register (CHR) is the most significant byte (MS Byte). Counter Low Register (CLR) is the least significant byte (LS Byte). Alternate Counter Register (ACR) Alternate Counter High Register (ACHR) is the most significant byte (MS Byte). Alternate Counter Low Register (ACLR) is the least significant byte (LS Byte). These two read-only 16-bit registers contain the same value but with the difference that reading the ACLR register does not clear the TOF bit (Timer overflow flag), located in the Status register, (SR), (see note at the end of paragraph titled 16-bit read sequence). Writing in the CLR register or ACLR register resets the free running counter to the FFFCh value. Both counters have a reset value of FFFCh (this is the only value which is reloaded in the 16-bit timer). The reset value of both counters is also FFFCh in One Pulse mode and PWM mode. The timer clock depends on the clock control bits of the CR2 register, as illustrated in Table 17 Clock Control Bits. The value in the counter register repeats every 131072, 262144 or 524288 CPU clock cycles depending on the CC[1:0] bits. The timer frequency can be fCPU/2, fCPU/4, fCPU/8 or an external frequency.
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16-BIT TIMER (Cont'd) Figure 48. Timer Block Diagram
ST7 INTERNAL BUS f CPU MCU-PERIPHERAL INTERFACE 8 low 8-bit buffer EXEDG 16 1/2 1/4 1/8 EX TCLK pin COUNTER REGISTER ALTERNATE COUNTER REGISTER 16 CC [1:0] TIMER INTERNAL BUS 16 16 OVERFLOW DE TECT CIRCUIT O UT PUT C OM P A R E REGISTER 1 O UT PUT COM PARE REGISTER 2 INPUT CAPTURE REGISTER 1 16 INPUT CAPTURE REGISTER 2 16 8 high low 8 high 8 low 8 high 8 low 8 high 8 low 8
8 high
OUTPUT COMPARE CIRCUIT 6
EDGE DETECT CIRCU IT1
IC AP1 pin
EDGE DETECT CIRCUIT2
IC AP2 pin
LATCH1
ICF1 OCF1 TOF ICF2 OCF2 TIMD
O C MP 1 pin O C MP 2 pin
0
0 LATCH2
(Control/Status Register) CSR
ICIE OCIE TOIE FOLV2 FOLV1 OLVL2 IEDG1 OLVL1
OC1E OC2E OPM PWM
CC1
CC0 IEDG2 EXEDG
(Control Register 1) CR1
(Control Register 2) CR2
(See note) TIMER INTERRUPT
Note: If IC, OC and TO interrupt requests have separate vectors then the last OR is not present (See device Interrupt Vector Table)
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16-BIT TIMER (Cont'd) 16-bit read sequence: (from either the Counter Register or the Alternate Counter Register). Beginning of the sequence At t0 Read MS Byte Other inst ructions Read At t0 +t LS Byte Sequence completed The user must read the MS Byte first, then the LS Byte value is buffered automatically. This buffered value remains unchanged until the 16-bit read sequence is completed, even if the user reads the MS Byte several times. After a complete reading sequence, if only the CLR register or ACLR register are read, they return the LS Byte of the count value at the time of the read. Whatever the timer mode used (input capture, output compare, One Pulse mode or PWM mode) an overflow occurs when the counter rolls over from FFFFh to 0000h then: The TOF bit of the SR register is set. A timer interrupt is generated if: TOIE bit of the CR1 register is set and I bit of the CC register is cleared. If one of these conditions is false, the interrupt remains pending to be issued as soon as they are both true.
Returns the buffered
LS Byte is buffered
LS Byte value at t0
Clearing the overflow interrupt request is done in two steps: 1. Reading the SR register while the TOF bit is set. 2. An access (read or write) to the CLR register. Notes: The TOF bit is not cleared by accesses to ACLR register. The advantage of accessing the ACLR register rather than the CLR register is that it allows simultaneous use of the overflow function and reading the free running counter at random times (for example, to measure elapsed time) without the risk of clearing the TOF bit erroneously. The timer is not affected by WAIT mode. In HALT mode, the counter stops counting until the mode is exited. Counting then resumes from the previous count (MCU awakened by an interrupt) or from the reset count (MCU awakened by a Reset). 10.4.3.2 External Clock The external clock (where available) is selected if CC0 = 1 and CC1 = 1 in the CR2 register. The status of the EXEDG bit in the CR2 register determines the type of level transition on the external clock pin EXTCLK that will trigger the free running counter. The counter is synchronized with the falling edge of the internal CPU clock. A minimum of four falling edges of the CPU clock must occur between two consecutive active edges of the external clock; thus the external clock frequency must be less than a quarter of the CPU clock frequency.
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16-BIT TIMER (Cont'd) Figure 49. Counter Timing Diagram, Internal Clock Divided by 2
CPU CLOCK INTERNAL RESET TIMER CLOCK COUNTER REGISTER TIMER OVERFLOW FLAG (TOF) FFFD FFFE FFFF 0000 0001 0002 0003
Figure 50. Counter Timing Diagram, Internal Clock Divided by 4
CPU CLOCK INTERNAL RESET TIMER CLOCK COUNTER REGISTER TIMER OVERFLOW FLAG (TOF) FFFC FFFD 0000 0001
Figure 51. Counter Timing Diagram, Internal Clock Divided By 8
CPU CLOCK INTERNAL RESET TIMER CLOCK COUNTER REGISTER TIMER OVERFLOW FLAG (TOF) FFFC FFFD 0000
Note: The MCU is in reset state when the internal reset signal is high, when it is low the MCU is running.
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16-BIT TIMER (Cont'd) 10.4.3.3 Input Capture In this section, the index, i, may be 1 or 2 because there are two input capture functions in the 16-bit timer. The two 16-bit input capture registers (IC1R and IC2R) are used to latch the value of the free running counter after a transition is detected on the ICAPi pin (see Figure 52).
ICiR MS Byte ICiHR LS Byte ICiLR
ICiR register is a read-only register. The active transition is software programmable through the IEDGi bit of Control Registers (CRi). Timing resolution is one count of the free running counter: (fCPU/CC[1:0]). Procedure: To use the input capture function select the following in the CR2 register: Select the timer clock (CC[1:0]) (see Table 17 Clock Control Bits). Select the edge of the active transition on the ICAP2 pin with the IEDG2 bit (the ICAP2 pin must be configured as floating input or input with pull-up without interrupt if this configuration is available). And select the following in the CR1 register: Set the ICIE bit to generate an interrupt after an input capture coming from either the ICAP1 pin or the ICAP2 pin Select the edge of the active transition on the ICAP1 pin with the IEDG1 bit (the ICAP1pin must be configured as floating input or input with pullup without interrupt if this configuration is available).
When an input capture occurs: ICFi bit is set. The ICiR register contains the value of the free running counter on the active transition on the ICAPi pin (see Figure 53). A timer interrupt is generated if the ICIE bit is set and the I bit is cleared in the CC register. Otherwise, the interrupt remains pending until both conditions become true. Clearing the Input Capture interrupt request (that is, clearing the ICFi bit) is done in two steps: 1. Reading the SR register while the ICFi bit is set. 2. An access (read or write) to the ICiLR register. Notes: 1. After reading the ICiHR register, transfer of input capture data is inhibited and ICFi will never be set until the ICiLR register is also read. 2. The ICiR register contains the free running counter value which corresponds to the most recent input capture. 3. The two input capture functions can be used together even if the timer also uses the two output compare functions. 4. In One Pulse mode and PWM mode only Input Capture 2 can be used. 5. The alternate inputs (ICAP1 and ICAP2) are always directly connected to the timer. So any transitions on these pins activates the input capture function. Moreover if one of the ICAPi pins is configured as an input and the second one as an output, an interrupt can be generated if the user toggles the output pin and if the ICIE bit is set. This can be avoided if the input capture function i is disabled by reading the ICiHR (see note 1). 6. The TOF bit can be used with interrupt generation in order to measure events that go beyond the timer range (FFFFh).
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16-BIT TIMER (Cont'd) Figure 52. Input Capture Block Diagram
ICAP1 pin ICAP2 pin EDGE DETECT CIRC UIT2 EDGE DETECT CIRC UIT1
ICIE
(Control Register 1) CR1
IEDG1
(Status Register) SR IC2R Register IC1R Register
ICF1 ICF2 0 0 0
16-BIT 16-BIT FREE RUNNING CO UNTER
(Control Register 2) CR2
CC1 CC0 IEDG2
Figure 53. Input Capture Timing Diagram
TIMER CLOCK COUNTER REGISTER ICAPi PIN ICAPi FLAG ICAPi REGISTER Note: The rising edge is the active edge. FF03 FF01 FF02 FF03
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16-BIT TIMER (Cont'd) 10.4.3.4 Output Compare In this section, the index, i, may be 1 or 2 because there are two output compare functions in the 16bit timer. This function can be used to control an output waveform or indicate when a period of time has elapsed. When a match is found between the Output Compare register and the free running counter, the output compare function: Assigns pins with a programmable value if the OCiE bit is set Sets a flag in the status register Generates an interrupt if enabled Two 16-bit registers Output Compare Register 1 (OC1R) and Output Compare Register 2 (OC2R) contain the value to be compared to the counter register each timer clock cycle.
OC i R MS Byte OCiHR LS Byte OCiLR
The OCMPi pin takes OLVLi bit value (OCMPi pin latch is forced low during reset). A timer interrupt is generated if the OCIE bit is set in the CR1 register and the I bit is cleared in the CC register (CC). The OCiR register value required for a specific timing application can be calculated using the following formula:
OCiR =
t * fCPU
PRESC
Where: t = Output compare period (in seconds) fCPU = CPU clock frequency (in hertz) = Timer prescaler factor (2, 4 or 8 dePRESC pending on CC[1:0] bits, see Table 17 Clock Control Bits) If the timer clock is an external clock, the formula is:
These registers are readable and writable and are not affected by the timer hardware. A reset event changes the OCiR value to 8000h. Timing resolution is one count of the free running counter: (fCPU/CC[1:0]). Procedure: To use the output compare function, select the following in the CR2 register: Set the OCiE bit if an output is needed then the OCMPi pin is dedicated to the output compare i signal. Select the timer clock (CC[1:0]) (see Table 17 Clock Control Bits). And select the following in the CR1 register: Select the OLVLi bit to applied to the OCMPi pins after the match occurs. Set the OCIE bit to generate an interrupt if it is needed. When a match is found between OCiR register and CR register: OCFi bit is set.
OCiR = t * fEXT
Where: t = Output compare period (in seconds) fEXT = External timer clock frequency (in hertz) Clearing the output compare interrupt request (that is, clearing the OCFi bit) is done by: 1. Reading the SR register while the OCFi bit is set. 2. An access (read or write) to the OCiLR register. The following procedure is recommended to prevent the OCFi bit from being set between the time it is read and the write to the OCiR register: Write to the OCiHR register (further compares are inhibited). Read the SR register (first step of the clearance of the OCFi bit, which may be already set). Write to the OCiLR register (enables the output compare function and clears the OCFi bit).
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16-BIT TIMER (Cont'd) Notes: 1. After a processor write cycle to the OCiHR register, the output compare function is inhibited until the OCiLR register is also written. 2. If the OCiE bit is not set, the OCMPi pin is a general I/O port and the OLVLi bit will not appear when a match is found but an interrupt could be generated if the OCIE bit is set. 3. In both internal and external clock modes, OCFi and OCMPi are set while the counter value equals the OCiR register value (see Figure 55 on page 80 for an example with fCPU/2 and Figure 56 on page 80 for an example with fCPU/4). This behavior is the same in OPM or PWM mode. 4. The output compare functions can be used both for generating external events on the OCMPi pins even if the input capture mode is also used. 5. The value in the 16-bit OCiR register and the OLVi bit should be changed after each successful comparison in order to control an output waveform or establish a new elapsed timeout. Figure 54. Output Compare Block Diagram
Forced Compare Output capability When the FOLVi bit is set by software, the OLVLi bit is copied to the OCMPi pin. The OLVi bit has to be toggled in order to toggle the OCMPi pin when it is enabled (OCiE bit = 1). The OCFi bit is then not set by hardware, and thus no interrupt request is generated. The FOLVLi bits have no effect in both One Pulse mode and PWM mode.
16 BIT FREE RUNNING COUNTER 16-bit OUTPUT COMPARE CIR CUIT 16-bit 16-bit
OC1E OC2E
CC1
CC0
(Control Register 2) CR2 (Control Register 1) CR1
OCIE FOLV2 FOLV1 OLVL2 OLVL1 Latch 1
OCM P1 Pin OCM P2 Pin
OC1R Register
OCF1 OCF2 0 0 0
Latch 2
OC2R Register (Status Register) SR
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16-BIT TIMER (Cont'd) Figure 55. Output Compare Timing Diagram, fTIMER = fCPU/2
INTERNAL CPU CLOCK TIMER CLOCK COUNTER REGISTER OUTPUT COMPARE REGISTER i (OCRi) OUTPUT COMPARE FLAG i (OCFi) OCMPi PIN (OLVLi = 1) 2ECF 2ED0 2ED1 2ED2 2ED3 2E D4 2ED3
Figure 56. Output Compare Timing Diagram, fTIMER = fCPU/4
INTERNAL CPU CLOCK TIMER CLOCK COUNTER REGISTER OUTPUT COMPARE REGISTER i (OCRi) OUTPUT COMPARE FLAG i (OCFi) OCMPi PIN (OLVLi = 1) 2ECF 2E D0 2ED1 2E D2 2ED3 2ED 4 2E D3
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16-BIT TIMER (Cont'd) 10.4.3.5 One Pulse Mode One Pulse mode enables the generation of a pulse when an external event occurs. This mode is selected via the OPM bit in the CR2 register. The One Pulse mode uses the Input Capture1 function and the Output Compare1 function. Procedure: To use One Pulse mode: 1. Load the OC1R register with the value corresponding to the length of the pulse (see the formula in the opposite column). 2. Select the following in the CR1 register: Using the OLVL1 bit, select the level to be applied to the OCMP1 pin after the pulse. Using the OLVL2 bit, select the level to be applied to the OCMP1 pin during the pulse. Select the edge of the active transition on the ICAP1 pin with the IEDG1 bit (the ICAP1 pin must be configured as floating input). 3. Select the following in the CR2 register: Set the OC1E bit, the OCMP1 pin is then dedicated to the Output Compare 1 function. Set the OPM bit. Select the timer clock CC[1:0] (see Table 17 Clock Control Bits). One Pulse mode cycle When event occurs on ICAP1 ICR1 = Counter OCMP1 = OLVL2 Counter is reset to FFFCh ICF1 bit is set When Counter = OC1R
Clearing the Input Capture interrupt request (that is, clearing the ICFi bit) is done in two steps: 1. Reading the SR register while the ICFi bit is set. 2. An access (read or write) to the ICiLR register. The OC1R register value required for a specific timing application can be calculated using the following formula: OCiR Value =
t * fCPU
PRESC
-5
Where: t = Pulse period (in seconds) fCPU = CPU clock frequency (in hertz) PRESC = Timer prescaler factor (2, 4 or 8 depending on the CC[1:0] bits, see Table 17 Clock Control Bits) If the timer clock is an external clock the formula is: OCiR = t * fEXT -5 Where: t = Pulse period (in seconds) fEXT = External timer clock frequency (in hertz) When the value of the counter is equal to the value of the contents of the OC1R register, the OLVL1 bit is output on the OCMP1 pin, (See Figure 57). Notes: 1. The OCF1 bit cannot be set by hardware in One Pulse mode but the OCF2 bit can generate an Output Compare interrupt. 2. When the Pulse Width Modulation (PWM) and One Pulse mode (OPM) bits are both set, the PWM mode is the only active one. 3. If OLVL1 = OLVL2 a continuous signal will be seen on the OCMP1 pin. 4. The ICAP1 pin can not be used to perform input capture. The ICAP2 pin can be used to perform input capture (ICF2 can be set and IC2R can be loaded) but the user must take care that the counter is reset each time a valid edge occurs on the ICAP1 pin and ICF1 can also generates interrupt if ICIE is set. 5. When One Pulse mode is used OC1R is dedicated to this mode. Nevertheless OC2R and OCF2 can be used to indicate a period of time has been elapsed but cannot generate an output waveform because the level OLVL2 is dedicated to the One Pulse mode.
OCMP1 = OLVL1
Then, on a valid event on the ICAP1 pin, the counter is initialized to FFFCh and OLVL2 bit is loaded on the OCMP1 pin, the ICF1 bit is set and the value FFFDh is loaded in the IC1R register. Because the ICF1 bit is set when an active edge occurs, an interrupt can be generated if the ICIE bit is set.
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16-BIT TIMER (Cont'd) Figure 57. One Pulse Mode Timing Example
IC1R COU NTER ICAP1 OC MP1 OLVL2 01F8 FFFC FFFD FFFE
01F8 2ED0 2ED 1 2ED2 2ED3
2ED3 FFFC FFFD
OLVL1
OLVL2
compare1
Note: IEDG1 = 1, OC1R = 2ED0h, OLVL1 = 0, OLVL2 = 1
Figure 58. Pulse Width Modulation Mode Timing Example with 2 Output Compare Functions
COUN TER 34E2 F F F C F F F D F F F E OCM P1 OLVL2
2ED0 2ED1 2ED2
34E2
FFFC
OLVL1
OLVL2
compare2
compare1
compare2
Note: OC1R = 2ED0h, OC2R = 34E2, OLVL1 = 0, OLVL2 = 1
Note: On timers with only one Output Compare register, a fixed frequency PWM signal can be generated using the output compare and the counter overflow to define the pulse length.
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16-BIT TIMER (Cont'd) 10.4.3.6 Pulse Width Modulation Mode Pulse Width Modulation (PWM) mode enables the generation of a signal with a frequency and pulse length determined by the value of the OC1R and OC2R registers. Pulse Width Modulation mode uses the complete Output Compare 1 function plus the OC2R register, and so this functionality can not be used when PWM mode is activated. In PWM mode, double buffering is implemented on the output compare registers. Any new values written in the OC1R and OC2R registers are taken into account only at the end of the PWM period (OC2) to avoid spikes on the PWM output pin (OCMP1). Procedure To use Pulse Width Modulation mode: 1. Load the OC2R register with the value corresponding to the period of the signal using the formula in the opposite column. 2. Load the OC1R register with the value corresponding to the period of the pulse if (OLVL1 = 0 and OLVL2 = 1) using the formula in the opposite column. 3. Select the following in the CR1 register: Using the OLVL1 bit, select the level to be applied to the OCMP1 pin after a successful comparison with the OC1R register. Using the OLVL2 bit, select the level to be applied to the OCMP1 pin after a successful comparison with the OC2R register. 4. Select the following in the CR2 register: Set OC1E bit: the OCMP1 pin is then dedicated to the output compare 1 function. Set the PWM bit. Select the timer clock (CC[1:0]) (see Table 17 Clock Control Bits). Pulse Width Modulation cycle When Counter = OC1R
If OLVL1 = 1 and OLVL2 = 0 the length of the positive pulse is the difference between the OC2R and OC1R registers. If OLVL1 = OLVL2 a continuous signal will be seen on the OCMP1 pin. The OCiR register value required for a specific timing application can be calculated using the following formula: OCiR Value =
t * fCPU
PRESC
-5
Where: t = Signal or pulse period (in seconds) fCPU = CPU clock frequency (in hertz) PRESC = Timer prescaler factor (2, 4 or 8 depending on CC[1:0] bits, see Table 17 Clock Control Bits) If the timer clock is an external clock the formula is: OCiR = t * fEXT -5 Where: t = Signal or pulse period (in seconds) fEXT = External timer clock frequency (in hertz) The Output Compare 2 event causes the counter to be initialized to FFFCh (See Figure 58) Notes: 1. After a write instruction to the OCiHR register, the output compare function is inhibited until the OCiLR register is also written. 2. The OCF1 and OCF2 bits cannot be set by hardware in PWM mode therefore the Output Compare interrupt is inhibited. 3. The ICF1 bit is set by hardware when the counter reaches the OC2R value and can produce a timer interrupt if the ICIE bit is set and the I bit is cleared. 4. In PWM mode the ICAP1 pin can not be used to perform input capture because it is disconnected to the timer. The ICAP2 pin can be used to perform input capture (ICF2 can be set and IC2R can be loaded) but the user must take care that the counter is reset each period and ICF1 can also generates interrupt if ICIE is set. 5. When the Pulse Width Modulation (PWM) and One Pulse mode (OPM) bits are both set, the PWM mode is the only active one.
OCMP1 = OLVL1
When Counter = OC2R
OCMP1 = OLVL2 Counter is reset to FFFCh ICF1 bit is set
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16-BIT TIMER (Cont'd) 10.4.4 Low Power Modes
Mode WAIT Description No effect on 16-bit Timer. Timer interrupts cause the device to exit from WAIT mode. 16-bit Timer registers are frozen. In HALT mode, the counter stops counting until Halt mode is exited. Counting resumes from the previous count when the MCU is woken up by an interrupt with "exit from HALT mode" capability or from the counter reset value when the MCU is woken up by a RESET. If an input capture event occurs on the ICAPi pin, the input capture detection circuitry is armed. Consequently, when the MCU is woken up by an interrupt with "exit from HALT mode" capability, the ICFi bit is set, and the counter value present when exiting from HALT mode is captured into the ICiR register.
H ALT
10.4.5 Interrupts
Interrupt Event Input Capture 1 event/Counter reset in PWM mode Input Capture 2 event Output Compare 1 event (not available in PWM mode) Output Compare 2 event (not available in PWM mode) Timer Overflow event Event Flag ICF1 ICF2 O CF 1 O CF 2 TOF Enable Control Bit ICIE OCIE TOIE Yes No Exit from Wait Exit from Halt
Note: The 16-bit Timer interrupt events are connected to the same interrupt vector (see Interrupts chapter). These events generate an interrupt if the corresponding Enable Control Bit is set and the interrupt mask in the CC register is reset (RIM instruction). 10.4.6 Summary of Timer Modes
M OD E S Input Capture (1 and/or 2) Output Compare (1 and/or 2) One Pulse Mode PWM Mode Input Capture 1 Yes No TIMER RESOURCES Input Capture 2 Output Compare 1 Output Compare 2 Yes Not Recommended1) Not Recommended3) Yes No Yes Partially 2) No
1) See note 4 in Section 10.4.3.5 "One Pulse Mode" 2) See note 5 in Section 10.4.3.5 "One Pulse Mode" 3) See note 4 in Section 10.4.3.6 "Pulse Width Modulation Mode"
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16-BIT TIMER (Cont'd) 10.4.7 Register Description Each Timer is associated with three control and status registers, and with six pairs of data registers (16-bit values) relating to the two input captures, the two output compares, the counter and the alternate counter. CONTROL REGISTER 1 (CR1) Read/Write Reset Value: 0000 0000 (00h)
7 0
Bit 4 = FOLV2 Forced Output Compare 2. This bit is set and cleared by software. 0: No effect on the OCMP2 pin. 1: Forces the OLVL2 bit to be copied to the OCMP2 pin, if the OC2E bit is set and even if there is no successful comparison. Bit 3 = FOLV1 Forced Output Compare 1. This bit is set and cleared by software. 0: No effect on the OCMP1 pin. 1: Forces OLVL1 to be copied to the OCMP1 pin, if the OC1E bit is set and even if there is no successful comparison. Bit 2 = OLVL2 Output Level 2. This bit is copied to the OCMP2 pin whenever a successful comparison occurs with the OC2R register and OCxE is set in the CR2 register. This value is copied to the OCMP1 pin in One Pulse mode and Pulse Width Modulation mode. Bit 1 = IEDG1 Input Edge 1. This bit determines which type of level transition on the ICAP1 pin will trigger the capture. 0: A falling edge triggers the capture. 1: A rising edge triggers the capture. Bit 0 = OLVL1 Output Level 1. The OLVL1 bit is copied to the OCMP1 pin whenever a successful comparison occurs with the OC1R register and the OC1E bit is set in the CR2 register.
ICIE OCIE TOIE FOLV2 FOLV1 OLVL2 IEDG1 OLVL1
Bit 7 = ICIE Input Capture Interrupt Enable. 0: Interrupt is inhibited. 1: A timer interrupt is generated whenever the ICF1 or ICF2 bit of the SR register is set. Bit 6 = OCIE Output Compare Interrupt Enable. 0: Interrupt is inhibited. 1: A timer interrupt is generated whenever the OCF1 or OCF2 bit of the SR register is set. Bit 5 = TOIE Timer Overflow Interrupt Enable. 0: Interrupt is inhibited. 1: A timer interrupt is enabled whenever the TOF bit of the SR register is set.
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16-BIT TIMER (Cont'd) CONTROL REGISTER 2 (CR2) Read/Write Reset Value: 0000 0000 (00h)
7 0
OC1E O C2 E O PM PW M C C1 CC0 I E D G 2 E XEDG
Bit 4 = PWM Pulse Width Modulation. 0: PWM mode is not active. 1: PWM mode is active, the OCMP1 pin outputs a programmable cyclic signal; the length of the pulse depends on the value of OC1R register; the period depends on the value of OC2R register. Bit 3, 2 = CC[1:0] Clock Control. The timer clock mode depends on these bits: Table 18. Clock Control Bits
Timer Clock fCPU / 4 fCPU / 2 fCPU / 8 External Clock (where available) CC1 0 1 C C0 0 1 0 1
Bit 7 = OC1E Output Compare 1 Pin Enable. This bit is used only to output the signal from the timer on the OCMP1 pin (OLV1 in Output Compare mode, both OLV1 and OLV2 in PWM and one-pulse mode). Whatever the value of the OC1E bit, the Output Compare 1 function of the timer remains active. 0: OCMP1 pin alternate function disabled (I/O pin free for general-purpose I/O). 1: OCMP1 pin alternate function enabled. Bit 6 = OC2E Output Compare 2 Pin Enable. This bit is used only to output the signal from the timer on the OCMP2 pin (OLV2 in Output Compare mode). Whatever the value of the OC2E bit, the Output Compare 2 function of the timer remains active. 0: OCMP2 pin alternate function disabled (I/O pin free for general-purpose I/O). 1: OCMP2 pin alternate function enabled. Bit 5 = OPM One Pulse Mode. 0: One Pulse mode is not active. 1: One Pulse mode is active, the ICAP1 pin can be used to trigger one pulse on the OCMP1 pin; the active transition is given by the IEDG1 bit. The length of the generated pulse depends on the contents of the OC1R register.
Note: If the external clock pin is not available, programming the external clock configuration stops the counter. Bit 1 = IEDG2 Input Edge 2. This bit determines which type of level transition on the ICAP2 pin will trigger the capture. 0: A falling edge triggers the capture. 1: A rising edge triggers the capture. Bit 0 = EXEDG External Clock Edge. This bit determines which type of level transition on the external clock pin EXTCLK will trigger the counter register. 0: A falling edge triggers the counter register. 1: A rising edge triggers the counter register.
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16-BIT TIMER (Cont'd) CONTROL/STATUS REGISTER (CSR) Read/Write (bits 7:3 read only) Reset Value: xxxx x0xx (xxh)
7 ICF1 OC F1 TOF ICF2 O C F 2 TIMD 0 0 0
Note: Reading or writing the ACLR register does not clear TOF. Bit 4 = ICF2 Input Capture Flag 2. 0: No input capture (reset value). 1: An input capture has occurred on the ICAP2 pin. To clear this bit, first read the SR register, then read or write the low byte of the IC2R (IC2LR) register. Bit 3 = OCF2 Output Compare Flag 2. 0: No match (reset value). 1: The content of the free running counter has matched the content of the OC2R register. To clear this bit, first read the SR register, then read or write the low byte of the OC2R (OC2LR) register. Bit 2 = TIMD Timer disable. This bit is set and cleared by software. When set, it freezes the timer prescaler and counter and disabled the output functions (OCMP1 and OCMP2 pins) to reduce power consumption. Access to the timer registers is still available, allowing the timer configuration to be changed, or the counter reset, while it is disabled. 0: Timer enabled 1: Timer prescaler, counter and outputs disabled Bits 1:0 = Reserved, must be kept cleared.
Bit 7 = ICF1 Input Capture Flag 1. 0: No input capture (reset value). 1: An input capture has occurred on the ICAP1 pin or the counter has reached the OC2R value in PWM mode. To clear this bit, first read the SR register, then read or write the low byte of the IC1R (IC1LR) register. Bit 6 = OCF1 Output Compare Flag 1. 0: No match (reset value). 1: The content of the free running counter has matched the content of the OC1R register. To clear this bit, first read the SR register, then read or write the low byte of the OC1R (OC1LR) register. Bit 5 = TOF Timer Overflow Flag. 0: No timer overflow (reset value). 1: The free running counter rolled over from FFFFh to 0000h. To clear this bit, first read the SR register, then read or write the low byte of the CR (CLR) register.
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16-BIT TIMER (Cont'd) INPUT CAPTURE 1 HIGH REGISTER (IC1HR) Read Only Reset Value: Undefined This is an 8-bit read only register that contains the high part of the counter value (transferred by the input capture 1 event).
7 MSB 0 LSB
OUTPUT COMPARE 1 HIGH REGISTER (OC1HR) Read/Write Reset Value: 1000 0000 (80h) This is an 8-bit register that contains the high part of the value to be compared to the CHR register.
7 MSB 0 LSB
INPUT CAPTURE 1 LOW REGISTER (IC1LR) Read Only Reset Value: Undefined This is an 8-bit read only register that contains the low part of the counter value (transferred by the input capture 1 event).
7 MSB 0 LSB
OUTPUT COMPARE 1 LOW REGISTER (OC1LR) Read/Write Reset Value: 0000 0000 (00h) This is an 8-bit register that contains the low part of the value to be compared to the CLR register.
7 MSB 0 LSB
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16-BIT TIMER (Cont'd) OUTPUT COMPARE 2 HIGH REGISTER (OC2HR) Read/Write Reset Value: 1000 0000 (80h) This is an 8-bit register that contains the high part of the value to be compared to the CHR register.
7 MSB 0 LSB
ALTERNATE COUNTER HIGH REGISTER (ACHR) Read Only Reset Value: 1111 1111 (FFh) This is an 8-bit register that contains the high part of the counter value.
7 MSB 0 LSB
OUTPUT COMPARE 2 LOW REGISTER (OC2LR) Read/Write Reset Value: 0000 0000 (00h) This is an 8-bit register that contains the low part of the value to be compared to the CLR register.
7 MSB 0 LSB
ALTERNATE COUNTER LOW REGISTER (ACLR) Read Only Reset Value: 1111 1100 (FCh) This is an 8-bit register that contains the low part of the counter value. A write to this register resets the counter. An access to this register after an access to CSR register does not clear the TOF bit in the CSR register.
7 0 LSB
COUNTER HIGH REGISTER (CHR) Read Only Reset Value: 1111 1111 (FFh) This is an 8-bit register that contains the high part of the counter value.
7 MSB 0 LSB
MSB
INPUT CAPTURE 2 HIGH REGISTER (IC2HR) Read Only Reset Value: Undefined This is an 8-bit read only register that contains the high part of the counter value (transferred by the Input Capture 2 event).
7 0 LSB
COUNTER LOW REGISTER (CLR) Read Only Reset Value: 1111 1100 (FCh) This is an 8-bit register that contains the low part of the counter value. A write to this register resets the counter. An access to this register after accessing the CSR register clears the TOF bit.
7 MSB 0 LSB
MSB
INPUT CAPTURE 2 LOW REGISTER (IC2LR) Read Only Reset Value: Undefined This is an 8-bit read only register that contains the low part of the counter value (transferred by the Input Capture 2 event).
7 MSB 0 LSB
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16-BIT TIMER (Cont'd) Table 19. 16-Bit Timer Register Map
Address (Hex.) 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F Register Name CR2 CR1 CSR IC 1HR IC 1LR OC1H R OC1LR CHR CLR ACHR ACLR IC 2HR IC 2LR OC2H R OC2LR 7 OC 1E ICIE ICF1 MSB MSB MSB MSB MSB MSB MSB MSB MSB MSB MSB MSB 6 O C2E OCIE OCF1 5 O PM TOIE TO F 4 PW M FO LV2 ICF2 3 CC1 FOLV1 OC F2 2 CC0 OLVL2 TIMD LSB LSB LSB LSB LSB LSB LSB LSB LSB LSB LSB LSB 1 IEDG 2 IEDG 1 0 E XEDG OLVL1
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10.5 8-BIT TIMER (TIM8) 10.5.1 Introduction The timer consists of a 8-bit free-running counter driven by a programmable prescaler. It may be used for a variety of purposes, including pulse length measurement of up to two input signals (input capture) or generation of up to two output waveforms (output compare and PWM). Pulse lengths and waveform periods can be modulated from a few microseconds to several milliseconds using the timer prescaler and the clock prescaler. 10.5.2 Main Features Programmable prescaler: fCPU divided by 2, 4 , 8 or fOSC2 divided by 8000. Overflow status flag and maskable interrupt Output compare functions with 2 dedicated 8-bit registers 2 dedicated programmable signals 2 dedicated status flags 1 dedicated maskable interrupt Input capture functions with 2 dedicated 8-bit registers 2 dedicated active edge selection signals 2 dedicated status flags 1 dedicated maskable interrupt Pulse width modulation mode (PWM) One pulse mode Reduced Power Mode 4 alternate functions on I/O ports (ICAP1, ICAP2, OCMP1, OCMP2)* The Block Diagram is shown in Figure 59. *Note: Some timer pins may not be available (not bonded) in some ST7 devices. Refer to the device pin out description. When reading an input signal on a non-bonded pin, the value will always be `1'. 10.5.3 Functional Description 10.5.3.1 Counter The main block of the Programmable Timer is a 8bit free running upcounter and its associated 8-bit registers. These two read-only 8-bit registers contain the same value but with the difference that reading the ACTR register does not clear the TOF bit (Timer overflow flag), located in the Status register, (SR). Writing in the CTR register or ACTR register resets the free running counter to the FCh value. Both counters have a reset value of FCh (this is the only value which is reloaded in the 8-bit timer). The reset value of both counters is also FCh in One Pulse mode and PWM mode. The timer clock depends on the clock control bits of the CR2 register, as shown in Table 19 Clock Control Bits. The value in the counter register repeats every 512, 1024, 2048 or 20480000 fCPU clock cycles depending on the CC[1:0] bits. The timer frequency can be fCPU/2, fCPU/4, fCPU/8 or fOSC2 /8000. For example, if fOSC2/8000 is selected, and fOSC2 = 8 MHz, the timer frequency will be 1 ms. Refer to Table 19 on page 105.
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8-BIT TIMER (Cont'd) Figure 59. Timer Block Diagram
ST7 INTERNAL BUS
fCPU
MCU-PERIPHERAL INTERFACE
8
8
8
8
8
1/2 1/4 1/8
COUNTER REGISTER ALTERNA TE COUN TER REGISTER 8
f OSC2
1/8000
O UT PUT COMP ARE RE GISTE R 1
OUTPUT CO MPARE REGISTER 2
INPUT CAPTURE REGISTER 1 8
INPUT CAPTUR E REGISTER 2 8
CC[1:0] TIMER INTERNAL BUS 8 8 OVERFLOW DETECT CIRCU IT
OUTPUT COMPARE CIRCUIT 6
EDGE DETECT CIR CUIT1
ICAP1 pin
EDGE DETECT CIRC UIT2
ICAP2 pin
LATCH1
ICF1 OCF1 TOF ICF2 OCF2 TIMD
OCMP 1 pin OCMP2 pin
0
0
0 LATCH2
(Control/Status Register) CSR
ICIE OCIE TOIE FOLV2 FOLV1 OLVL2 IEDG1 OLVL1
OC1E OC2E OPM PWM
CC1
CC0 IEDG2
(Control Register 1) CR1
(Control Register 2) CR2
(See note) TIMER INTERRUPT
Note: If IC, OC and TO interrupt requests have separate vectors then the last OR is not present (See device Interrupt Vector Table)
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8-BIT TIMER (Cont'd) Whatever the timer mode used (input capture, output compare, one pulse mode or PWM mode) an overflow occurs when the counter rolls over from FFh to 00h then: The TOF bit of the SR register is set. A timer interrupt is generated if: TOIE bit of the CR1 register is set and I bit of the CC register is cleared. If one of these conditions is false, the interrupt remains pending to be issued as soon as they are both true. Clearing the overflow interrupt request is done in two steps: 1. Reading the SR register while the TOF bit is set. 2. An access (read or write) to the CTR register.
Notes: The TOF bit is not cleared by accesses to ACTR register. The advantage of accessing the ACTR register rather than the CTR register is that it allows simultaneous use of the overflow function and reading the free running counter at random times (for example, to measure elapsed time) without the risk of clearing the TOF bit erroneously. The timer is not affected by WAIT mode. In HALT mode, the counter stops counting until the mode is exited. Counting then resumes from the previous count (MCU awakened by an interrupt) or from the reset count (MCU awakened by a Reset).
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8-BIT TIMER (Cont'd) Figure 60. Counter Timing Diagram, Internal Clock Divided by 2 fCPU CLOCK
INTERNAL RESET TIMER CLOCK COUNTER REGISTER TIMER OVERFLOW FLAG (TOF) FD FE FF 00 01 02 03
Figure 61. Counter Timing Diagram, Internal Clock Divided by 4 fCPU CLOCK
INTERNAL RESET TIMER CLOCK COUNTER REGISTER TIMER OVERFLOW FLAG (TOF) FC FD 00 01
Figure 62. Counter Timing Diagram, Internal Clock Divided by 8 fCPU CLOCK
INTERNAL RESET TIMER CLOCK COUNTER REGISTER TIMER OVERFLOW FLAG (TOF) FC FD 00
Note: The MCU is in reset state when the internal reset signal is high, when it is low the MCU is running.
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8-BIT TIMER (Cont'd) 10.5.3.2 Input Capture In this section, the index, i, may be 1 or 2 because there are two input capture functions in the 8-bit timer. The two 8-bit input capture registers (IC1R and IC2R) are used to latch the value of the free running counter after a transition is detected on the ICAPi pin (see Figure 63). ICiR register is a read-only register. The active transition is software programmable through the IEDGi bit of Control Registers (CRi). Timing resolution is one count of the free running counter (see Table 19 Clock Control Bits). Procedure: To use the input capture function select the following in the CR2 register: Select the timer clock (CC[1:0]) (see Table 19 Clock Control Bits). Select the edge of the active transition on the ICAP2 pin with the IEDG2 bit (the ICAP2 pin must be configured as floating input or input with pull-up without interrupt if this configuration is available). And select the following in the CR1 register: Set the ICIE bit to generate an interrupt after an input capture coming from either the ICAP1 pin or the ICAP2 pin Select the edge of the active transition on the ICAP1 pin with the IEDG1 bit (the ICAP1 pin must be configured as floating input or input with pull-up without interrupt if this configuration is available).
When an input capture occurs: ICFi bit is set. The ICiR register contains the value of the free running counter on the active transition on the ICAPi pin (see Figure 64). A timer interrupt is generated if the ICIE bit is set and the interrrupt mask is cleared in the CC register. Otherwise, the interrupt remains pending until both conditions become true. Clearing the Input Capture interrupt request (that is, clearing the ICFi bit) is done in two steps: 1. Reading the SR register while the ICFi bit is set. 2. An access (read or write) to the ICiR register. Notes: 1. The ICiR register contains the free running counter value which corresponds to the most recent input capture. 2. The two input capture functions can be used together even if the timer also uses the two output compare functions. 3. Once the ICIE bit is set both input capture features may trigger interrupt requests. If only one is needed in the application, the interrupt routine software needs to discard the unwanted capture interrupt. This can be done by checking the ICF1 and ICF2 flags and resetting them both. 4. In One pulse Mode and PWM mode only Input Capture 2 can be used. 5. The alternate inputs (ICAP1 and ICAP2) are always directly connected to the timer. So any transitions on these pins activates the input capture function. Moreover if one of the ICAPi pins is configured as an input and the second one as an output, an interrupt can be generated if the user toggles the output pin and if the ICIE bit is set. 6. The TOF bit can be used with interrupt generation in order to measure events that go beyond the timer range (FFh).
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8-BIT TIMER (Cont'd) Figure 63. Input Capture Block Diagram
ICAP1 pin ICAP2 pin EDGE DETECT CIRC UIT2 EDGE DETECT CIRC UIT1
ICIE
(Control Register 1) CR1
IEDG1
(Status Register) SR IC2R Register IC1R Register
ICF1 ICF2 0 0 0
8-bit 8-bit FREE RUNNING CO UNTER
(Control Register 2) CR2
CC1 CC0 IEDG2
Figure 64. Input Capture Timing Diagram
TIMER CLOCK COUNTER REGISTER ICAPi PIN ICAPi FLAG ICAPi REGISTER Note: The rising edge is the active edge. 03 01 02 03
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8-BIT TIMER (Cont'd) 10.5.3.3 Output Compare In this section, the index, i, may be 1 or 2 because there are two output compare functions in the 8-bit timer. This function can be used to control an output waveform or indicate when a period of time has elapsed. When a match is found between the Output Compare register and the free running counter, the output compare function: Assigns pins with a programmable value if the OCiE bit is set Sets a flag in the status register Generates an interrupt if enabled Two 8-bit registers Output Compare Register 1 (OC1R) and Output Compare Register 2 (OC2R) contain the value to be compared to the counter register each timer clock cycle. These registers are readable and writable and are not affected by the timer hardware. A reset event changes the OCiR value to 00h. Timing resolution is one count of the free running counter: (fCPU/CC[1:0]). Procedure: To use the output compare function, select the following in the CR2 register: Set the OCiE bit if an output is needed then the OCMPi pin is dedicated to the output compare i signal. Select the timer clock (CC[1:0]) (see Table 19 Clock Control Bits). And select the following in the CR1 register:
Select the OLVLi bit to applied to the OCMPi pins after the match occurs. Set the OCIE bit to generate an interrupt if it is needed. When a match is found between OCRi register and CR register: OCFi bit is set. The OCMPi pin takes OLVLi bit value (OCMPi pin latch is forced low during reset). A timer interrupt is generated if the OCIE bit is set in the CR1 register and the I bit is cleared in the CC register (CC). The OCiR register value required for a specific timing application can be calculated using the following formula:
OCiR =
t * fCPU
PRESC
Where: t = Output compare period (in seconds) fCPU = PLL output x2 clock frequency in hertz (or fOSC/2 if PLL is not enabled) = Timer prescaler factor (2, 4, 8 or 8000 PRESC depending on CC[1:0] bits, see Table 19 Clock Control Bits) Clearing the output compare interrupt request (that is, clearing the OCFi bit) is done by: 1. Reading the SR register while the OCFi bit is set. 2. An access (read or write) to the OCiR register.
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8-BIT TIMER (Cont'd) Notes: 1. Once the OCIE bit is set both output compare features may trigger interrupt requests. If only one is needed in the application, the interrupt routine software needs to discard the unwanted compare interrupt. This can be done by checking the OCF1 and OCF2 flags and resetting them both. 2. If the OCiE bit is not set, the OCMPi pin is a general I/O port and the OLVLi bit will not appear when a match is found but an interrupt could be generated if the OCIE bit is set. 3. When the timer clock is fCPU/2, OCFi and OCMPi are set while the counter value equals the OCiR register value (see Figure 66 on page 99). This behaviour is the same in OPM or PWM mode. When the timer clock is fCPU/4, fCPU/8 or fCPU/ 8000, OCFi and OCMPi are set while the counter value equals the OCiR register value plus 1 (see Figure 67 on page 99). 4. The output compare functions can be used both for generating external events on the OCMPi pins even if the input capture mode is also used. 5. The value in the 8-bit OCiR register and the OLVi bit should be changed after each sucFigure 65. Output Compare Block Diagram
cessful comparison in order to control an output waveform or establish a new elapsed timeout. Forced Compare Output capability When the FOLVi bit is set by software, the OLVLi bit is copied to the OCMPi pin. The OLVi bit has to be toggled in order to toggle the OCMPi pin when it is enabled (OCiE bit = 1). The OCFi bit is then not set by hardware, and thus no interrupt request is generated. The FOLVLi bits have no effect in both one pulse mode and PWM mode.
8 BIT 8-bit
FREE RUNNING COUNTER
OC1E OC2E
CC1
CC0
(Control Register 2) CR2 (Control Register 1) CR1
OUTPUT COMPARE CIR CUIT 8-bit 8-bit
OCIE
FOLV2 FOLV1 OLVL2
OLVL1
Latch 1
OCM P1 Pin OCM P2 Pin
OC1R Register
OCF1 OCF2 0 0 0
Latch 2
OC2R Register (Status Register) SR
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8-BIT TIMER (Cont'd) Figure 66. Output Compare Timing Diagram, fTIMER = fCPU/2
fCPU CLOCK
TIMER CLOCK COUNTER REGISTER OUTPUT COMPARE REGISTER i (OCRi) OUTPUT COMPARE FLAG i (OCFi) OCMPi PIN (OLVLi = 1) CF D0 D1 D3 D2 D3 D4
Figure 67. Output Compare Timing Diagram, fTIMER = fCPU/4
fCPU CLOCK
TIMER CLOCK COUNTER REGISTER OUTPUT COMPARE REGISTER i (OCRi) COMPARE REGISTER i LATCH OUTPUT COMPARE FLAG i (OCFi) OCMPi PIN (OLVLi = 1) CF D0 D1 D3 D2 D3 D4
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8-BIT TIMER (Cont'd) 10.5.3.4 One Pulse Mode One Pulse mode enables the generation of a pulse when an external event occurs. This mode is selected via the OPM bit in the CR2 register. The one pulse mode uses the Input Capture1 function and the Output Compare1 function. Procedure: To use one pulse mode: 1. Load the OC1R register with the value corresponding to the length of the pulse (see the formula in the opposite column). 2. Select the following in the CR1 register: Using the OLVL1 bit, select the level to be applied to the OCMP1 pin after the pulse. Using the OLVL2 bit, select the level to be applied to the OCMP1 pin during the pulse. Select the edge of the active transition on the ICAP1 pin with the IEDG1 bit (the ICAP1 pin must be configured as floating input). 3. Select the following in the CR2 register: Set the OC1E bit, the OCMP1 pin is then dedicated to the Output Compare 1 function. Set the OPM bit. Select the timer clock CC[1:0] (see Table 19 Clock Control Bits). One pulse mode cycle When event occurs on ICAP1 ICR1 = Counter OCMP1 = OLVL2 Counter is reset to FCh ICF1 bit is set When Counter = OC1R
Clearing the Input Capture interrupt request (that is, clearing the ICFi bit) is done in two steps: 1. Reading the SR register while the ICFi bit is set. 2. An access (read or write) to the ICiLR register. The OC1R register value required for a specific timing application can be calculated using the following formula: t * fCPU - 5 OCiR Value =
PRESC
Where: t = Pulse period (in seconds) fCPU = PLL output x2 clock frequency in hertz (or fOSC/2 if PLL is not enabled) PRESC = Timer prescaler factor (2, 4, 8 or 8000 depending on the CC[1:0] bits, see Table 19 Clock Control Bits) When the value of the counter is equal to the value of the contents of the OC1R register, the OLVL1 bit is output on the OCMP1 pin, (See Figure 68). Notes: 1. The OCF1 bit cannot be set by hardware in one pulse mode but the OCF2 bit can generate an Output Compare interrupt. 2. When the Pulse Width Modulation (PWM) and One Pulse Mode (OPM) bits are both set, the PWM mode is the only active one. 3. If OLVL1=OLVL2 a continuous signal will be seen on the OCMP1 pin. 4. The ICAP1 pin can not be used to perform input capture. The ICAP2 pin can be used to perform input capture (ICF2 can be set and IC2R can be loaded) but the user must take care that the counter is reset each time a valid edge occurs on the ICAP1 pin and ICF1 can also generates interrupt if ICIE is set. 5. When one pulse mode is used OC1R is dedicated to this mode. Nevertheless OC2R and OCF2 can be used to indicate a period of time has been elapsed but cannot generate an output waveform because the level OLVL2 is dedicated to the one pulse mode.
OCMP1 = OLVL1
Then, on a valid event on the ICAP1 pin, the counter is initialized to FCh and OLVL2 bit is loaded on the OCMP1 pin, the ICF1 bit is set and the value FFFDh is loaded in the IC1R register. Because the ICF1 bit is set when an active edge occurs, an interrupt can be generated if the ICIE bit is set.
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8-BIT TIMER (Cont'd) Figure 68. One Pulse Mode Timing Example
IC1R COU NTER ICAP1 OC MP1 OLVL2 F8 FC FD FE
F8 D0 D1 D2 D3
D3 FC FD
OLVL1
OLVL2
compare1
Note: IEDG1 = 1, OC1R = D0h, OLVL1 = 0, OLVL2 = 1
Figure 69. Pulse Width Modulation Mode Timing Example
COUN TER E2 OCM P1
FC
FD
FE OLVL2
D0
D1
D2
E2
FC OLVL2
OLVL1
compare2
compare1
compare2
Note: OC1R = D0h, OC2R = E2, OLVL1 = 0, OLVL2 = 1
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8-BIT TIMER (Cont'd) 10.5.3.5 Pulse Width Modulation Mode Pulse Width Modulation (PWM) mode enables the generation of a signal with a frequency and pulse length determined by the value of the OC1R and OC2R registers. Pulse Width Modulation mode uses the complete Output Compare 1 function plus the OC2R register, and so this functionality can not be used when PWM mode is activated. In PWM mode, double buffering is implemented on the output compare registers. Any new values written in the OC1R and OC2R registers are taken into account only at the end of the PWM period (OC2) to avoid spikes on the PWM output pin (OCMP1). Procedure To use pulse width modulation mode: 1. Load the OC2R register with the value corresponding to the period of the signal using the formula in the opposite column. 2. Load the OC1R register with the value corresponding to the period of the pulse if (OLVL1 = 0 and OLVL2 = 1) using the formula in the opposite column. 3. Select the following in the CR1 register: Using the OLVL1 bit, select the level to be applied to the OCMP1 pin after a successful comparison with the OC1R register. Using the OLVL2 bit, select the level to be applied to the OCMP1 pin after a successful comparison with the OC2R register. 4. Select the following in the CR2 register: Set OC1E bit: the OCMP1 pin is then dedicated to the output compare 1 function. Set the PWM bit. Select the timer clock (CC[1:0]) (see Table 19 Clock Control Bits). Pulse Width Modulation cycle When Counter = OC1R
If OLVL1 = 1 and OLVL2 = 0 the length of the positive pulse is the difference between the OC2R and OC1R registers. If OLVL1 = OLVL2 a continuous signal will be seen on the OCMP1 pin. The OCiR register value required for a specific timing application can be calculated using the following formula: t * fCPU - 5 OCiR Value =
PRESC
Where: t = Signal or pulse period (in seconds) fCPU = PLL output x2 clock frequency in hertz (or fOSC/2 if PLL is not enabled) PRESC = Timer prescaler factor (2, 4, 8 or 8000 depending on CC[1:0] bits, see Table 19 Clock Control Bits) The Output Compare 2 event causes the counter to be initialized to FCh (See Figure 69) Notes: 1. The OCF1 and OCF2 bits cannot be set by hardware in PWM mode therefore the Output Compare interrupt is inhibited. 2. The ICF1 bit is set by hardware when the counter reaches the OC2R value and can produce a timer interrupt if the ICIE bit is set and the I bit is cleared. 3. In PWM mode the ICAP1 pin can not be used to perform input capture because it is disconnected to the timer. The ICAP2 pin can be used to perform input capture (ICF2 can be set and IC2R can be loaded) but the user must take care that the counter is reset each period and ICF1 can also generates interrupt if ICIE is set. 4. When the Pulse Width Modulation (PWM) and One Pulse Mode (OPM) bits are both set, the PWM mode is the only active one.
OCMP1 = OLVL1
When Counter = OC2R
OCMP1 = OLVL2 Counter is reset to FCh ICF1 bit is set
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8-BIT TIMER (Cont'd) 10.5.4 Low Power Modes
Mode WAIT Description No effect on 8-bit Timer. Timer interrupts cause the device to exit from WAIT mode. 8-bit Timer registers are frozen. In HALT mode, the counter stops counting until Halt mode is exited. Counting resumes from the previous count when the MCU is woken up by an interrupt with "exit from HALT mode" capability or from the counter reset value when the MCU is woken up by a RESET. If an input capture event occurs on the ICAPi pin, the input capture detection circuitry is armed. Consequently, when the MCU is woken up by an interrupt with "exit from HALT mode" capability, the ICFi bit is set, and the counter value present when exiting from HALT mode is captured into the ICiR register.
H ALT
10.5.5 Interrupts
Interrupt Event Input Capture 1 event/Counter reset in PWM mode Input Capture 2 event Output Compare 1 event (not available in PWM mode) Output Compare 2 event (not available in PWM mode) Timer Overflow event Event Flag ICF1 ICF2 O CF 1 O CF 2 TOF Enable Control Bit ICIE OCIE TOIE Yes No Exit from Wait Exit from Halt
Note: The 8-bit Timer interrupt events are connected to the same interrupt vector (see Interrupts chapter). These events generate an interrupt if the corresponding Enable Control Bit is set and the interrupt mask in the CC register is reset (RIM instruction). 10.5.6 Summary of Timer modes
M OD E S Input Capture (1 and/or 2) Output Compare (1 and/or 2) One Pulse Mode PWM Mode Input Capture 1 Yes No AVAILABLE RESOURCES Input Capture 2 Output Compare 1 Output Compare 2 Yes Not Recommended1) Not Recommended3) Yes No Yes Partially 2) No
1) See note 4 in "One Pulse Mode" on page 100 2) See note 5 in "One Pulse Mode" on page 100 3) See note 4 in "Pulse Width Modulation Mode" on page 102
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8-BIT TIMER (Cont'd) 10.5.7 Register Description Each Timer is associated with three control and status registers, and with six data registers (8-bit values) relating to the two input captures, the two output compares, the counter and the alternate counter. CONTROL REGISTER 1 (CR1) Read/Write Reset Value: 0000 0000 (00h)
7 0
Bit 4 = FOLV2 Forced Output Compare 2. This bit is set and cleared by software. 0: No effect on the OCMP2 pin. 1: Forces the OLVL2 bit to be copied to the OCMP2 pin, if the OC2E bit is set and even if there is no successful comparison. Bit 3 = FOLV1 Forced Output Compare 1. This bit is set and cleared by software. 0: No effect on the OCMP1 pin. 1: Forces OLVL1 to be copied to the OCMP1 pin, if the OC1E bit is set and even if there is no successful comparison. Bit 2 = OLVL2 Output Level 2. This bit is copied to the OCMP2 pin whenever a successful comparison occurs with the OC2R register and OCxE is set in the CR2 register. This value is copied to the OCMP1 pin in One Pulse Mode and Pulse Width Modulation mode. Bit 1 = IEDG1 Input Edge 1. This bit determines which type of level transition on the ICAP1 pin will trigger the capture. 0: A falling edge triggers the capture. 1: A rising edge triggers the capture. Bit 0 = OLVL1 Output Level 1. The OLVL1 bit is copied to the OCMP1 pin whenever a successful comparison occurs with the OC1R register and the OC1E bit is set in the CR2 register.
ICIE OCIE TOIE FOLV2 FOLV1 OLVL2 IEDG1 OLVL1
Bit 7 = ICIE Input Capture Interrupt Enable. 0: Interrupt is inhibited. 1: A timer interrupt is generated whenever the ICF1 or ICF2 bit of the SR register is set. Bit 6 = OCIE Output Compare Interrupt Enable. 0: Interrupt is inhibited. 1: A timer interrupt is generated whenever the OCF1 or OCF2 bit of the SR register is set. Bit 5 = TOIE Timer Overflow Interrupt Enable. 0: Interrupt is inhibited. 1: A timer interrupt is enabled whenever the TOF bit of the SR register is set.
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8-BIT TIMER (Cont'd) CONTROL REGISTER 2 (CR2) Read/Write Reset Value: 0000 0000 (00h)
7 OC1E O C2 E O PM PW M C C1 CC0 I E D G 2 0 0
Bit 4 = PWM Pulse Width Modulation. 0: PWM mode is not active. 1: PWM mode is active, the OCMP1 pin outputs a programmable cyclic signal; the length of the pulse depends on the value of OC1R register; the period depends on the value of OC2R register. Bit 3, 2 = CC[1:0] Clock Control. The timer clock mode depends on these bits: Table 20. Clock Control Bits
Timer Clock fCPU / 4 fCPU / 2 fCPU / 8 fOSC2 / 8000* CC1 0 0 1 1 CC0 0 1 0 1
Bit 7 = OC1E Output Compare 1 Pin Enable. This bit is used only to output the signal from the timer on the OCMP1 pin (OLV1 in Output Compare mode, both OLV1 and OLV2 in PWM and one-pulse mode). Whatever the value of the OC1E bit, the Output Compare 1 function of the timer remains active. 0: OCMP1 pin alternate function disabled (I/O pin free for general-purpose I/O). 1: OCMP1 pin alternate function enabled. Bit 6 = OC2E Output Compare 2 Pin Enable. This bit is used only to output the signal from the timer on the OCMP2 pin (OLV2 in Output Compare mode). Whatever the value of the OC2E bit, the Output Compare 2 function of the timer remains active. 0: OCMP2 pin alternate function disabled (I/O pin free for general-purpose I/O). 1: OCMP2 pin alternate function enabled. Bit 5 = OPM One Pulse Mode. 0: One Pulse Mode is not active. 1: One Pulse Mode is active, the ICAP1 pin can be used to trigger one pulse on the OCMP1 pin; the active transition is given by the IEDG1 bit. The length of the generated pulse depends on the contents of the OC1R register.
* Not available in Slow mode in ST72F561. Bit 1 = IEDG2 Input Edge 2. This bit determines which type of level transition on the ICAP2 pin will trigger the capture. 0: A falling edge triggers the capture. 1: A rising edge triggers the capture. Bit 0 = Reserved, must be kept at 0.
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8-BIT TIMER (Cont'd) CONTROL/STATUS REGISTER (CSR) Read Only (except bit 2 R/W) Reset Value: 0000 0000 (00h)
7 ICF1 OC F1 TOF ICF2 O C F 2 TIMD 0 0 0
Note: Reading or writing the ACTR register does not clear TOF. Bit 4 = ICF2 Input Capture Flag 2. 0: No input capture (reset value). 1: An input capture has occurred on the ICAP2 pin. To clear this bit, first read the SR register, then read or write the IC2R register. Bit 3 = OCF2 Output Compare Flag 2. 0: No match (reset value). 1: The content of the free running counter has matched the content of the OC2R register. To clear this bit, first read the SR register, then read or write the OC2R register. Bit 2 = TIMD Timer disable. This bit is set and cleared by software. When set, it freezes the timer prescaler and counter and disabled the output functions (OCMP1 and OCMP2 pins) to reduce power consumption. Access to the timer registers is still available, allowing the timer configuration to be changed, or the counter reset, while it is disabled. 0: Timer enabled 1: Timer prescaler, counter and outputs disabled Bits 1:0 = Reserved, must be kept cleared.
Bit 7 = ICF1 Input Capture Flag 1. 0: No input capture (reset value). 1: An input capture has occurred on the ICAP1 pin or the counter has reached the OC2R value in PWM mode. To clear this bit, first read the SR register, then read or write the the IC1R register. Bit 6 = OCF1 Output Compare Flag 1. 0: No match (reset value). 1: The content of the free running counter has matched the content of the OC1R register. To clear this bit, first read the SR register, then read or write the OC1R register. Bit 5 = TOF Timer Overflow Flag. 0: No timer overflow (reset value). 1: The free running counter rolled over from FFh to 00h. To clear this bit, first read the SR register, then read or write the CTR register.
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8-BIT TIMER (Cont'd) INPUT CAPTURE 1 REGISTER (IC1R) Read Only Reset Value: Undefined This is an 8-bit read only register that contains the counter value (transferred by the input capture 1 event).
7 MSB 0 LSB
COUNTER REGISTER (CTR) Read Only Reset Value: 1111 1100 (FCh) This is an 8-bit register that contains the counter value. A write to this register resets the counter. An access to this register after accessing the CSR register clears the TOF bit.
7 MSB 0 LSB
OUTPUT COMPARE 1 REGISTER (OC1R) Read/Write Reset Value: 0000 0000 (00h) This is an 8-bit register that contains the value to be compared to the CTR register.
7 MSB 0 LSB
ALTERNATE COUNTER REGISTER (ACTR) Read Only Reset Value: 1111 1100 (FCh) This is an 8-bit register that contains the counter value. A write to this register resets the counter. An access to this register after an access to CSR register does not clear the TOF bit in the CSR regis ter.
7 0 LSB
OUTPUT COMPARE 2 REGISTER (OC2R) Read/Write Reset Value: 0000 0000 (00h) This is an 8-bit register that contains the value to be compared to the CTR register.
7 MSB 0 LSB
MSB
INPUT CAPTURE 2 REGISTER (IC2R) Read Only Reset Value: Undefined This is an 8-bit read only register that contains the counter value (transferred by the Input Capture 2 event).
7 MSB 0 LSB
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8-BIT TIMER (Cont'd) 10.5.8 8-bit Timer Register Map
Address (Hex.) 3C 3D 3E 3F 40 41 42 43 44 Register Name CR2 CR1 CSR IC 1R OC1R CTR ACTR IC 2R OC2R 7 OC 1E ICIE ICF1 MSB MSB MSB MSB MSB MSB 6 O C2E OCIE OCF1 5 O PM TOIE TO F 4 PW M FO LV2 ICF2 3 CC1 FOLV1 OC F2 2 CC0 OLVL2 TIMD LSB LSB LSB LSB LSB LSB 1 IEDG 2 IEDG 1 0 0 OLVL1
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ON-CHIP PERIPHERALS (cont'd) 10.6 SERIAL PERIPHERAL INTERFACE (SPI) 10.6.1 Introduction The Serial Peripheral Interface (SPI) allows fullduplex, synchronous, serial communication with external devices. An SPI system may consist of a master and one or more slaves or a system in which devices may be either masters or slaves. 10.6.2 Main Features Full duplex synchronous transfers (on three lines) Simplex synchronous transfers (on two lines) Master or slave operation 6 master mode frequencies (fCPU/4 max.) fCPU/2 max. slave mode frequency (see note) SS Management by software or hardware Programmable clock polarity and phase End of transfer interrupt flag Write collision, Master Mode Fault and Overrun flags Note: In slave mode, continuous transmission is not possible at maximum frequency due to the software overhead for clearing status flags and to initiate the next transmission sequence. 10.6.3 General Description Figure 70 on page 110 shows the serial peripheral interface (SPI) block diagram. There are three regis ters : SPI Control Register (SPICR) SPI Control/Status Register (SPICSR) SPI Data Register (SPIDR) The SPI is connected to external devices through four pins: MISO: Master In / Slave Out data MOSI: Master Out / Slave In data SCK: Serial Clock out by SPI masters and input by SPI slaves SS: Slave select: This input signal acts as a `chip select' to let the SPI master communicate with slaves individually and to avoid contention on the data lines. Slave SS inputs can be driven by standard I/O ports on the master Device.
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SERIAL PERIPHERAL INTERFACE (SPI) (cont'd) Figure 70. Serial Peripheral Interface Block Diagram
Data/Address Bus SPIDR Read Read Buffer Interrupt request
MOSI MISO
8-bit Shift Register
7 SPIF WCOL OVR MODF 0
SPICSR
SOD SSM
0 SSI
SOD bit
Write
SS
SPI S T AT E CONTROL
7 SPIE
1 0
SC K
SP ICR
0
SPE SPR2 MSTR CPOL CPHA SPR1 SPR0
MASTER CON T ROL SERIAL CLOCK G ENERATO R
SS
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SERIAL PERIPHERAL INTERFACE (cont'd) 10.6.3.1 Functional Description A basic example of interconnections between a single master and a single slave is illustrated in Figure 71. The MOSI pins are connected together and the MISO pins are connected together. In this way data is transferred serially between master and slave (most significant bit first). The communication is always initiated by the master. When the master device transmits data to a slave device via MOSI pin, the slave device responds by sending data to the master device via Figure 71. Single Master/ Single Slave Application
MA STER M SBit LSBit MISO
the MISO pin. This implies full duplex communication with both data out and data in synchronized with the same clock signal (which is provided by the master device via the SCK pin). To use a single data line, the MISO and MOSI pins must be connected at each node (in this case only simplex communication is possible). Four possible data/clock timing relationships may be chosen (see Figure 74 on page 114) but master and slave must be programmed with the same timing mode.
SLAV E MSBit MISO L S B it
8-bit SHIFT REGISTER
8-bit SHIFT REGISTER
M OS I
MO SI
SPI CLOCK G ENERATO R
SCK SS +5V
SC K SS Not used if SS is managed by software
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SERIAL PERIPHERAL INTERFACE (cont'd) 10.6.3.2 Slave Select Management As an alternative to using the SS pin to control the Slave Select signal, the application can choose to manage the Slave Select signal by software. This is configured by the SSM bit in the SPICSR register (see Figure 73). In software management, the external SS pin is free for other application uses and the internal SS signal level is driven by writing to the SSI bit in the SPICSR register. In Master mode: SS internal must be held high continuously
In Slave Mode: There are two cases depending on the data/clock timing relationship (see Figure 72): If CPHA = 1 (data latched on second clock edge): SS internal must be held low during the entire transmission. This implies that in single slave applications the SS pin either can be tied to VSS, or made free for standard I/O by managing the SS function by software (SSM = 1 and SSI = 0 in the in the SPICSR register) If CPHA = 0 (data latched on first clock edge): SS internal must be held low during byte transmission and pulled high between each byte to allow the slave to write to the shift register. If SS is not pulled high, a Write Collision error will occur when the slave writes to the shift register (see Section 10.6.5.3).
Figure 72. Generic SS Timing Diagram
MOSI/MISO Master SS Slave SS (if CPHA = 0) Slave SS (if CPHA = 1)
Byte 1
Byte 2
Byte 3
Figure 73. Hardware/Software Slave Select Management SSM bit
SSI bit SS external pin
1 0
SS internal
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SERIAL PERIPHERAL INTERFACE (cont'd) 10.6.3.3 Master Mode Operation In master mode, the serial clock is output on the SCK pin. The clock frequency, polarity and phase are configured by software (refer to the description of the SPICSR register). Note: The idle state of SCK must correspond to the polarity selected in the SPICSR register (by pulling up SCK if CPOL = 1 or pulling down SCK if CPOL = 0). How to operate the SPI in master mode To operate the SPI in master mode, perform the following steps in order: 1. Write to the SPICR register: Select the clock frequency by configuring the SPR[2:0] bits. Select the clock polarity and clock phase by configuring the CPOL and CPHA bits. Figure 74 shows the four possible configurations. Note: The slave must have the same CPOL and CPHA settings as the master. 2. Write to the SPICSR register: Either set the SSM bit and set the SSI bit or clear the SSM bit and tie the SS pin high for the complete byte transmit sequence. 3. Write to the SPICR register: Set the MSTR and SPE bits Note: MSTR and SPE bits remain set only if SS is high). Important note: if the SPICSR register is not written first, the SPICR register setting (MSTR bit) may be not taken into account. The transmit sequence begins when software writes a byte in the SPIDR register. 10.6.3.4 Master Mode Transmit Sequence When software writes to the SPIDR register, the data byte is loaded into the 8-bit shift register and then shifted out serially to the MOSI pin most significant bit first. When data transfer is complete: The SPIF bit is set by hardware. An interrupt request is generated if the SPIE bit is set and the interrupt mask in the CCR register is cleared. Clearing the SPIF bit is performed by the following software sequence: 1. An access to the SPICSR register while the SPIF bit is set 2. A read to the SPIDR register
Note: While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR register is read. 10.6.3.5 Slave Mode Operation In slave mode, the serial clock is received on the SCK pin from the master device. To operate the SPI in slave mode: 1. Write to the SPICSR register to perform the following actions: Select the clock polarity and clock phase by configuring the CPOL and CPHA bits (see Figure 74). Note: The slave must have the same CPOL and CPHA settings as the master. Manage the SS pin as described in Section 10.6.3.2 and Figure 72. If CPHA = 1 SS must be held low continuously. If CPHA = 0 SS must be held low during byte transmission and pulled up between each byte to let the slave write in the shift register. 2. Write to the SPICR register to clear the MSTR bit and set the SPE bit to enable the SPI I/O functions. 10.6.3.6 Slave Mode Transmit Sequence When software writes to the SPIDR register, the data byte is loaded into the 8-bit shift register and then shifted out serially to the MISO pin most significant bit first. The transmit sequence begins when the slave device receives the clock signal and the most significant bit of the data on its MOSI pin. When data transfer is complete: The SPIF bit is set by hardware. An interrupt request is generated if SPIE bit is set and interrupt mask in the CCR register is cleared. Clearing the SPIF bit is performed by the following software sequence: 1. An access to the SPICSR register while the SPIF bit is set 2. A write or a read to the SPIDR register Notes: While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR register is read. The SPIF bit can be cleared during a second transmission; however, it must be cleared before the second SPIF bit in order to prevent an Overrun condition (see Section 10.6.5.2).
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SERIAL PERIPHERAL INTERFACE (cont'd) 10.6.4 Clock Phase and Clock Polarity Four possible timing relationships may be chosen by software, using the CPOL and CPHA bits (See Figure 74). Note: The idle state of SCK must correspond to the polarity selected in the SPICSR register (by pulling up SCK if CPOL = 1 or pulling down SCK if CPOL = 0). The combination of the CPOL clock polarity and CPHA (clock phase) bits selects the data capture clock edge. Figure 74. Data Clock Timing Diagram
Figure 74 shows an SPI transfer with the four combinations of the CPHA and CPOL bits. The diagram may be interpreted as a master or slave timing diagram where the SCK pin, the MISO pin and the MOSI pin are directly connected between the master and the slave device. Note: If CPOL is changed at the communication byte boundaries, the SPI must be disabled by resetting the SPE bit.
CPHA = 1
SCK (CPOL = 1) SCK (CPOL = 0)
MISO (from master) MOSI (from slave) SS (to slave)
CAPTURE STROBE
MSBit
Bit 6
Bit 5
Bit 4
Bit3
Bit 2
Bit 1
LSBit
MSBit
Bit 6
Bit 5
Bit 4
Bit3
Bit 2
Bit 1
LSBit
CPHA = 0
SCK (CPOL = 1) SCK (CPOL = 0)
MISO (from master) MOSI (from slave) SS (to slave)
CAPTURE STROBE
MSBit
Bit 6
Bit 5
Bit 4
Bit3
Bit 2
Bi t 1
LSBit
MSBit
Bit 6
Bit 5
Bit 4
Bit3
Bit 2
Bit 1
LSBit
Note: This figure should not be used as a replacement for parametric information. Refer to the Electrical Characteristics chapter.
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SERIAL PERIPHERAL INTERFACE (cont'd) 10.6.5 Error Flags 10.6.5.1 Master Mode Fault (MODF) Master mode fault occurs when the master device's SS pin is pulled low. When a Master mode fault occurs: The MODF bit is set and an SPI interrupt request is generated if the SPIE bit is set. The SPE bit is reset. This blocks all output from the device and disables the SPI peripheral. The MSTR bit is reset, thus forcing the device into slave mode. Clearing the MODF bit is done through a software sequence: 1. A read access to the SPICSR register while the MODF bit is set. 2. A write to the SPICR register. Notes: To avoid any conflicts in an application with multiple slaves, the SS pin must be pulled high during the MODF bit clearing sequence. The SPE and MSTR bits may be restored to their original state during or after this clearing sequence. Hardware does not allow the user to set the SPE and MSTR bits while the MODF bit is set except in the MODF bit clearing sequence. In a slave device, the MODF bit can not be set, but in a multimaster configuration the device can be in slave mode with the MODF bit set. The MODF bit indicates that there might have been a multimaster conflict and allows software to handle this using an interrupt routine and either perform a reset or return to an application default state.
10.6.5.2 Overrun Condition (OVR) An overrun condition occurs when the master device has sent a data byte and the slave device has not cleared the SPIF bit issued from the previously transmitted byte. When an Overrun occurs: The OVR bit is set and an interrupt request is generated if the SPIE bit is set. In this case, the receiver buffer contains the byte sent after the SPIF bit was last cleared. A read to the SPIDR register returns this byte. All other bytes are lost. The OVR bit is cleared by reading the SPICSR register. 10.6.5.3 Write Collision Error (WCOL) A write collision occurs when the software tries to write to the SPIDR register while a data transfer is taking place with an external device. When this happens, the transfer continues uninterrupted and the software write will be unsuccessful. Write collisions can occur both in master and slave mode. See also Section 10.6.3.2 "Slave Select Management". Note: A "read collision" will never occur since the received data byte is placed in a buffer in which access is always synchronous with the CPU operation. The WCOL bit in the SPICSR register is set if a write collision occurs. No SPI interrupt is generated when the WCOL bit is set (the WCOL bit is a status flag only). Clearing the WCOL bit is done through a software sequence (see Figure 75).
Figure 75. Clearing the WCOL Bit (Write Collision Flag) Software Sequence
Clearing sequence after SPIF = 1 (end of a data byte transfer) 1st Step Read SPICSR
2nd Step
Read SPIDR
RESULT SPIF = 0 W C OL = 0
Clearing sequence before SPIF = 1 (during a data byte transfer) 1st Step Read SPICSR RESULT 2nd Step Read SPIDR W C OL = 0 Note: Writing to the SPIDR register instead of reading it does not reset the WCOL bit.
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SERIAL PERIPHERAL INTERFACE (cont'd) 10.6.5.4 Single Master and Multimaster Configurations There are two types of SPI systems: Single Master System Multimaster System Single Master System A typical single master system may be configured using a device as the master and four devices as slaves (see Figure 76). The master device selects the individual slave devices by using four pins of a parallel port to control the four SS pins of the slave devices. The SS pins are pulled high during reset since the master device ports will be forced to be inputs at that time, thus disabling the slave devices. Note: To prevent a bus conflict on the MISO line, the master allows only one active slave device during a transmission.
For more security, the slave device may respond to the master with the received data byte. Then the master will receive the previous byte back from the slave device if all MISO and MOSI pins are connected and the slave has not written to its SPIDR register. Other transmission security methods can use ports for handshake lines or data bytes with command fields. Multimaster System A multimaster system may also be configured by the user. Transfer of master control could be implemented using a handshake method through the I/O ports or by an exchange of code messages through the serial peripheral interface system. The multimaster system is principally handled by the MSTR bit in the SPICR register and the MODF bit in the SPICSR register.
Figure 76. Single Master / Multiple Slave Configuration
SS SCK Slave Device MOSI MISO SCK Slave Device MO SI
SS S CK Slave Device MOS I
SS SC K Slave Device MOSI
SS
MISO
MISO
MISO
MOSI MISO Ports SCK Master Device 5V SS
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SERIAL PERIPHERAL INTERFACE (cont'd) 10.6.6 Low Power Modes
Mode WAIT Description No effect on SPI. SPI interrupt events cause the device to exit from WAIT mode. SPI registers are frozen. In HALT mode, the SPI is inactive. SPI operation resumes when the device is woken up by an interrupt with "exit from HALT mode" capability. The data received is subsequently read from the SPIDR register when the software is running (interrupt vector fetching). If several data are received before the wakeup event, then an overrun error is generated. This error can be detected after the fetch of the interrupt routine that woke up the Device.
HALT
the SPI from HALT mode state to normal state. If the SPI exits from Slave mode, it returns to normal state immediately. Caution: The SPI can wake up the device from HALT mode only if the Slave Select signal (external SS pin or the SSI bit in the SPICSR register) is low when the device enters HALT mode. So, if Slave selection is configured as external (see Section 10.6.3.2), make sure the master drives a low level on the SS pin when the slave enters HALT mode. 10.6.7 Interrupts
Interrupt Event SPI End of Transfer Event Master Mode Fault Event Overrun Error Event Flag SPIF M OD F OVR SPIE Yes No Enable Control Bit Exit from Wait Exit from Halt Yes
10.6.6.1 Using the SPI to wake up the device from Halt mode In slave configuration, the SPI is able to wake up the device from HALT mode through a SPIF interrupt. The data received is subsequently read from the SPIDR register when the software is running (interrupt vector fetch). If multiple data transfers have been performed before software clears the SPIF bit, then the OVR bit is set by hardware. Note: When waking up from HALT mode, if the SPI remains in Slave mode, it is recommended to perform an extra communications cycle to bring
Note: The SPI interrupt events are connected to the same interrupt vector (see Interrupts chapter). They generate an interrupt if the corresponding Enable Control Bit is set and the interrupt mask in the CC register is reset (RIM instruction).
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10.6.8 Register Description SPI CONTROL REGISTER (SPICR) Read/Write Reset Value: 0000 xxxx (0xh)
7
SPIE SPE SPR2 MSTR CPOL CPHA SPR1
0
SPR0
Bit 7 = SPIE Serial Peripheral Interrupt Enable This bit is set and cleared by software. 0: Interrupt is inhibited 1: An SPI interrupt is generated whenever an End of Transfer event, Master Mode Fault or Overrun error occurs (SPIF = 1, MODF = 1 or OVR = 1 in the SPICSR register) Bit 6 = SPE Serial Peripheral Output Enable This bit is set and cleared by software. It is also cleared by hardware when, in master mode, SS = 0 (see Section 10.6.5.1 "Master Mode Fault (MODF)"). The SPE bit is cleared by reset, so the SPI peripheral is not initially connected to the external pins. 0: I/O pins free for general purpose I/O 1: SPI I/O pin alternate functions enabled Bit 5 = SPR2 Divider Enable This bit is set and cleared by software and is cleared by reset. It is used with the SPR[1:0] bits to set the baud rate. Refer to Table 20 SPI Master Mode SCK Frequency. 0: Divider by 2 enabled 1: Divider by 2 disabled Note: This bit has no effect in slave mode. Bit 4 = MSTR Master Mode This bit is set and cleared by software. It is also cleared by hardware when, in master mode, SS = 0 (see Section 10.6.5.1 "Master Mode Fault (MODF)"). 0: Slave mode 1: Master mode. The function of the SCK pin changes from an input to an output and the functions of the MISO and MOSI pins are reversed.
Bit 3 = CPOL Clock Polarity This bit is set and cleared by software. This bit determines the idle state of the serial Clock. The CPOL bit affects both the master and slave modes. 0: SCK pin has a low level idle state 1: SCK pin has a high level idle state Note: If CPOL is changed at the communication byte boundaries, the SPI must be disabled by resetting the SPE bit. Bit 2 = CPHA Clock Phase This bit is set and cleared by software. 0: The first clock transition is the first data capture edge. 1: The second clock transition is the first capture edge. Note: The slave must have the same CPOL and CPHA settings as the master. Bits 1:0 = SPR[1:0] Serial Clock Frequency These bits are set and cleared by software. Used with the SPR2 bit, they select the baud rate of the SPI serial clock SCK output by the SPI in master mode. Note: These 2 bits have no effect in slave mode. Table 21. SPI Master Mode SCK Frequency
Serial Clock fCPU/4 fCPU/8 fCPU/16 fCPU/32 fCPU/64 fCPU/128 S PR2 1 0 1 0 1 0 SPR1 SPR0 0 1 0 1
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SERIAL PERIPHERAL INTERFACE (cont'd) SPI CONTROL/STATUS REGISTER (SPICSR) Read/Write (some bits Read Only) Reset Value: 0000 0000 (00h)
7 SPIF WCOL OVR MODF SOD SSM 0 SSI
Bit 2 = SOD SPI Output Disable This bit is set and cleared by software. When set, it disables the alternate function of the SPI output (MOSI in master mode / MISO in slave mode) 0: SPI output enabled (if SPE = 1) 1: SPI output disabled Bit 1 = SSM SS Management This bit is set and cleared by software. When set, it disables the alternate function of the SPI SS pin and uses the SSI bit value instead. See Section 10.6.3.2 "Slave Select Management". 0: Hardware management (SS managed by external pin) 1: Software management (internal SS signal controlled by SSI bit. External SS pin free for general-purpose I/O) Bit 0 = SSI SS Internal Mode This bit is set and cleared by software. It acts as a `chip select' by controlling the level of the SS slave select signal when the SSM bit is set. 0: Slave selected 1: Slave deselected SPI DATA I/O REGISTER (SPIDR) Read/Write Reset Value: Undefined
7 D7 D6 D5 D4 D3 D2 D1 0 D0
Bit 7 = SPIF Serial Peripheral Data Transfer Flag (Read only) This bit is set by hardware when a transfer has been completed. An interrupt is generated if SPIE = 1 in the SPICR register. It is cleared by a software sequence (an access to the SPICSR register followed by a write or a read to the SPIDR register). 0: Data transfer is in progress or the flag has been cleared. 1: Data transfer between the device and an external device has been completed. Note: While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR register is read. Bit 6 = WCOL Write Collision status (Read only) This bit is set by hardware when a write to the SPIDR register is done during a transmit sequence. It is cleared by a software sequence (see Figure 75). 0: No write collision occurred 1: A write collision has been detected Bit 5 = OVR SPI Overrun error (Read only) This bit is set by hardware when the byte currently being received in the shift register is ready to be transferred into the SPIDR register while SPIF = 1 (See Section 10.6.5.2). An interrupt is generated if SPIE = 1 in the SPICR register. The OVR bit is cleared by software reading the SPICSR register. 0: No overrun error 1: Overrun error detected Bit 4 = MODF Mode Fault flag (Read only) This bit is set by hardware when the SS pin is pulled low in master mode (see Section 10.6.5.1 "Master Mode Fault (MODF)"). An SPI interrupt can be generated if SPIE = 1 in the SPICR register. This bit is cleared by a software sequence (An access to the SPICSR register while MODF = 1 followed by a write to the SPICR register). 0: No master mode fault detected 1: A fault in master mode has been detected Bit 3 = Reserved, must be kept cleared.
The SPIDR register is used to transmit and receive data on the serial bus. In a master device, a write to this register will initiate transmission/reception of another byte. Notes: During the last clock cycle the SPIF bit is set, a copy of the received data byte in the shift register is moved to a buffer. When the user reads the serial peripheral data I/O register, the buffer is actually being read. While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR register is read. Warning: A write to the SPIDR register places data directly into the shift register for transmission. A read to the SPIDR register returns the value located in the buffer and not the content of the shift register (see Figure 70).
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SERIAL PERIPHERAL INTERFACE (Cont'd) Table 22. SPI Register Map and Reset Values
Address (Hex.) 21 22 23 Register Label SPIDR Reset Value SPICR Reset Value SPICSR Reset Value 7 MS B x SPIE 0 SPIF 0 6 5 4 3 2 1 0 LSB x SPR0 x SSI 0
x SP E 0 WCOL 0
x SPR2 0 OVR 0
x M ST R 0 M OD F 0
x CPOL x 0
x CPHA x SO D 0
x SPR1 x SS M 0
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10.7 LINSCI SERIAL COMMUNICATION INTERFACE (LIN MASTER/SLAVE) 10.7.1 Introduction The Serial Communications Interface (SCI) offers a flexible means of full-duplex data exchange with external equipment requiring an industry standard NRZ asynchronous serial data format. The SCI offers a very wide range of baud rates using two baud rate generator systems. The LIN-dedicated features support the LIN (Local Interconnect Network) protocol for both master and slave nodes. This chapter is divided into SCI Mode and LIN mode sections. For information on general SCI communications, refer to the SCI mode section. For LIN applications, refer to both the SCI mode and LIN mode sections. 10.7.2 SCI Features Full duplex, asynchronous communications NRZ standard format (Mark/Space) Independently programmable transmit and receive baud rates up to 500K baud Programmable data word length (8 or 9 bits) Receive buffer full, Transmit buffer empty and End of Transmission flags 2 receiver wake-up modes: Address bit (MSB) Idle line Muting function for multiprocessor configurations Separate enable bits for Transmitter and Receiver Overrun, Noise and Frame error detection 6 interrupt sources Transmit data register empty Transmission complete Receive data register full Idle line received Overrun error Parity interrupt Parity control: Transmits parity bit Checks parity of received data byte Reduced power consumption mode 10.7.3 LIN Features LIN Master 13-bit LIN Synch Break generation LIN Slave Automatic Header Handling Automatic baud rate resynchronization based on recognition and measurement of the LIN Synch Field (for LIN slave nodes) Automatic baud rate adjustment (at CPU frequency precision) 11-bit LIN Synch Break detection capability LIN Parity check on the LIN Identifier Field (only in reception) LIN Error management LIN Header Timeout Hot plugging support
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LINSCITM SERIAL COMMUNICATION INTERFACE (cont'd) 10.7.4 General Description A conventional type for commonly-used baud rates The interface is externally connected to another An extended type with a prescaler offering a very device by two pins: wide range of baud rates even with non-standard TDO: Transmit Data Output. When the transmitoscillator frequencies ter is disabled, the output pin returns to its I/O A LIN baud rate generator with automatic resynport configuration. When the transmitter is enabled and nothing is to be transmitted, the TDO chronization pin is at high level. RDI: Receive Data Input is the serial data input. Oversampling techniques are used for data recovery by discriminating between valid incoming data and noise. Through these pins, serial data is transmitted and received as characters comprising: An Idle Line prior to transmission or reception A start bit A data word (8 or 9 bits) least significant bit first A Stop bit indicating that the character is complete This interface uses three types of baud rate generator:
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LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) Figure 77. SCI Block Diagram (in Conventional Baud Rate Generator Mode)
Write
Read
(DATA REGISTER) SCIDR
Transmit Data Register (TDR) TDO Transmit Shift Register RDI
Received Data Register (RDR)
Receive Shift Register
SCICR1
R8 T8 SCID M
WAKE PCE
PS PIE
TRANSMIT CONTROL
WAKE UP UNIT
RECEIVER CONTROL
RECEIVER CLOCK
SC ICR 2
TIE TCIE RIE ILIE TE RE RWU SBK OR/ TDRE TC RDRF IDLE LHE NF FE
SCISR
PE
SCI INTERRUPT CONTROL TRANSMITTER CLOCK TRANSMITTER RATE
f CPU
CONTROL
/16
/PR SCIBRR
SCP1 SCP0 SCT2 SCT1 SCT0 SCR2 SCR1SCR0
RECEIVER RATE CONTROL CONVENTIONAL BAUD RATE GENERATOR
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LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) 10.7.5 SCI Mode - Functional Description 10.7.5.1 Serial Data Format Conventional Baud Rate Generator Mode Word length may be selected as being either 8 or 9 bits by programming the M bit in the SCICR1 regThe block diagram of the Serial Control Interface ister (see Figure 2). in conventional baud rate generator mode is The TDO pin is in low state during the start bit. shown in Figure 1. It uses four registers: The TDO pin is in high state during the stop bit. 2 control registers (SCICR1 and SCICR2) An Idle character is interpreted as a continuous logic high level for 10 (or 11) full bit times. A status register (SCISR) A Break character is a character with a sufficient A baud rate register (SCIBRR) number of low level bits to break the normal data Extended Prescaler Mode format followed by an extra "1" bit to acknowledge the start bit. Two additional prescalers are available in extended prescaler mode. They are shown in Figure 3. An extended prescaler receiver register (SCIERP R) An extended prescaler transmitter register (SCIETPR) Figure 78. Word Length Programming 9-bit Word length (M bit is set) Data Character
Start Bit Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Possible Parity Bit Bit8
Next Data Character
Next Stop S t a r t Bit Bit Start Bit
Idle Line
Break Character
Extra '1'
Start Bit
8-bit Word length (M bit is reset) Data Character
Start Bit Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6
Possible Parity Bit Bit7 Stop Bit
Next Data Character
Next Start Bit Start Bit Extra Start Bit '1'
Idle Line Break Character
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LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) 10.7.5.2 Transmitter When no transmission is taking place, a write instruction to the SCIDR register places the data diThe transmitter can send data words of either 8 or rectly in the shift register, the data transmission 9 bits depending on the M bit status. When the M starts, and the TDRE bit is immediately set. bit is set, word length is 9 bits and the 9th bit (the When a character transmission is complete (after MSB) has to be stored in the T8 bit in the SCICR1 the stop bit) the TC bit is set and an interrupt is register. generated if the TCIE is set and the I[1:0] bits are Character Transmission cleared in the CCR register. During an SCI transmission, data shifts out least Clearing the TC bit is performed by the following significant bit first on the TDO pin. In this mode, software sequence: the SCIDR register consists of a buffer (TDR) be1. An access to the SCISR register tween the internal bus and the transmit shift regis2. A write to the SCIDR register ter (see Figure 1). Note: The TDRE and TC bits are cleared by the Procedure same software sequence. Select the M bit to define the word length. Break Characters Select the desired baud rate using the SCIBRR Setting the SBK bit loads the shift register with a and the SCIETPR registers. break character. The break character length de Set the TE bit to send a preamble of 10 (M = 0) pends on the M bit (see Figure 2). or 11 (M = 1) consecutive ones (Idle Line) as first As long as the SBK bit is set, the SCI sends break transmission. characters to the TDO pin. After clearing this bit by Access the SCISR register and write the data to software, the SCI inserts a logic 1 bit at the end of send in the SCIDR register (this sequence clears the last break character to guarantee the recognithe TDRE bit). Repeat this sequence for each tion of the start bit of the next character. data to be transmitted. Idle Line Clearing the TDRE bit is always performed by the Setting the TE bit drives the SCI to send a preamfollowing software sequence: ble of 10 (M = 0) or 11 (M = 1) consecutive `1's 1. An access to the SCISR register (idle line) before the first character. 2. A write to the SCIDR register In this case, clearing and then setting the TE bit The TDRE bit is set by hardware and it indicates: during a transmission sends a preamble (idle line) The TDR register is empty. after the current word. Note that the preamble duration (10 or 11 consecutive `1's depending on the The data transfer is beginning. M bit) does not take into account the stop bit of the The next data can be written in the SCIDR regisprevious character. ter without overwriting the previous data. Note: Resetting and setting the TE bit causes the This flag generates an interrupt if the TIE bit is set data in the TDR register to be lost. Therefore the and the I[|1:0] bits are cleared in the CCR register. best time to toggle the TE bit is when the TDRE bit When a transmission is taking place, a write inis set, that is, before writing the next byte in the struction to the SCIDR register stores the data in SCIDR. the TDR register and which is copied in the shift register at the end of the current transmission.
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LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) 10.7.5.3 Receiver The OR bit is set. The SCI can receive data words of either 8 or 9 The RDR content will not be lost. bits. When the M bit is set, word length is 9 bits The shift register will be overwritten. and the MSB is stored in the R8 bit in the SCICR1 An interrupt is generated if the RIE bit is set and register. the I[|1:0] bits are cleared in the CCR register. Character reception The OR bit is reset by an access to the SCISR regDuring a SCI reception, data shifts in least signifiister followed by a SCIDR register read operation. cant bit first through the RDI pin. In this mode, the Noise Error SCIDR register consists or a buffer (RDR) between the internal bus and the received shift regisOversampling techniques are used for data recovter (see Figure 1). ery by discriminating between valid incoming data and noise. Procedure When noise is detected in a character: Select the M bit to define the word length. The NF bit is set at the rising edge of the RDRF Select the desired baud rate using the SCIBRR bit. and the SCIERPR registers. Data is transferred from the Shift register to the Set the RE bit, this enables the receiver which SCIDR register. begins searching for a start bit. No interrupt is generated. However this bit rises When a character is received: at the same time as the RDRF bit which itself The RDRF bit is set. It indicates that the content generates an interrupt. of the shift register is transferred to the RDR. The NF bit is reset by a SCISR register read oper An interrupt is generated if the RIE bit is set and ation followed by a SCIDR register read operation. the I[1:0] bits are cleared in the CCR register. Framing Error The error flags can be set if a frame error, noise A framing error is detected when: or an overrun error has been detected during reception. The stop bit is not recognized on reception at the expected time, following either a desynchronizaClearing the RDRF bit is performed by the following tion or excessive noise. software sequence done by: A break is received. 1. An access to the SCISR register When the framing error is detected: 2. A read to the SCIDR register. the FE bit is set by hardware The RDRF bit must be cleared before the end of the reception of the next character to avoid an overrun Data is transferred from the Shift register to the error. SCIDR register. Idle Line No interrupt is generated. However this bit rises at the same time as the RDRF bit which itself When an idle line is detected, there is the same generates an interrupt. procedure as a data received character plus an interrupt if the ILIE bit is set and the I[|1:0] bits are The FE bit is reset by a SCISR register read opercleared in the CCR register. ation followed by a SCIDR register read operation. Overrun Error Break Character An overrun error occurs when a character is re When a break character is received, the SCI ceived when RDRF has not been reset. Data can handles it as a framing error. To differentiate a not be transferred from the shift register to the break character from a framing error, it is necesTDR register as long as the RDRF bit is not sary to read the SCIDR. If the received value is cleared. 00h, it is a break character. Otherwise it is a framing error. When an overrun error occurs:
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LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) 10.7.5.4 Conventional Baud Rate Generation 10.7.5.5 Extended Baud Rate Generation The baud rates for the receiver and transmitter (Rx The extended prescaler option gives a very fine and Tx) are set independently and calculated as tuning on the baud rate, using a 255 value prescaler, whereas the conventional Baud Rate Generafollows: tor retains industry standard software compatibilifCPU fCPU ty. Rx = Tx = The extended baud rate generator block diagram (16*PR)*RR (16*PR)*TR is described in Figure 3. with: The output clock rate sent to the transmitter or to PR = 1, 3, 4 or 13 (see SCP[1:0] bits) the receiver will be the output from the 16 divider divided by a factor ranging from 1 to 255 set in the TR = 1, 2, 4, 8, 16, 32, 64,128 SCIERPR or the SCIETPR register. (see SCT[2:0] bits) Note: The extended prescaler is activated by setRR = 1, 2, 4, 8, 16, 32, 64,128 ting the SCIETPR or SCIERPR register to a value (see SCR[2:0] bits) other than zero. The baud rates are calculated as follows: All these bits are in the SCIBRR register. Example: If fCPU is 8 MHz (normal mode) and if fCPU f CPU PR = 13 and TR = RR = 1, the transmit and reRx = Tx = ceive baud rates are 38400 baud. 16*ERPR*(PR*RR) 16*ETPR*(PR*TR) Note: The baud rate registers MUST NOT be changed while the transmitter or the receiver is enwith: abled. ETPR = 1, ..., 255 (see SCIETPR register) ERPR = 1, ..., 255 (see SCIERPR register)
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LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) Figure 79. SCI Baud Rate and Extended Prescaler Block Diagram
TRANSMITTER CLOCK EXTENDED PRESCALER TRANSMITTER RATE CONTROL
SCIETPR
EXTENDED TRANSMITTER PRESCALER REGISTER
SCIERPR
EXTENDED RECEIVER PRESCALER REGISTER RECEIVER CLOCK EXTENDED PRESCALER RECEIVER RATE CONTROL EXTENDED PRESCALER
fCPU
TRANSMITTER RATE CONTROL
/16
/PR SCIBRR
SCP1 SCP0 SCT2 SCT1 SCT0 SCR2 SCR1SCR0
RECEIVER RATE CONTROL CONVENTIONAL BAUD RATE GENERATOR
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LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) 10.7.5.6 Receiver Muting and Wake-up Feature ceived an address character (most significant bit = '1'), the receivers are waken up. The receivers In multiprocessor configurations it is often desirawhich are not addressed set RWU bit to enter in ble that only the intended message recipient mute mode. Consequently, they will not treat the should actively receive the full message contents, next characters constituting the next part of the thus reducing redundant SCI service overhead for message. all non-addressed receivers. 10.7.5.7 Parity Control The non-addressed devices may be placed in Hardware byte Parity control (generation of parity sleep mode by means of the muting function. bit in transmission and parity checking in recepSetting the RWU bit by software puts the SCI in tion) can be enabled by setting the PCE bit in the sleep mode: SCICR1 register. Depending on the character forAll the reception status bits can not be set. mat defined by the M bit, the possible SCI character formats are as listed in Table 1. All the receive interrupts are inhibited. Note: In case of wake-up by an address mark, the A muted receiver may be woken up in one of the MSB bit of the data is taken into account and not following ways: the parity bit by Idle Line detection if the WAKE bit is reset, by Address Mark detection if the WAKE bit is set. Idle Line Detection Receiver wakes up by Idle Line detection when the Receive line has recognized an Idle Line. Then the RWU bit is reset by hardware but the IDLE bit is not set. This feature is useful in a multiprocessor system when the first characters of the message determine the address and when each message ends by an idle line: As soon as the line becomes idle, every receivers is waken up and analyse the first characters of the message which indicates the addressed receiver. The receivers which are not addressed set RWU bit to enter in mute mode. Consequently, they will not treat the next characters constituting the next part of the message. At the end of the message, an idle line is sent by the transmitter: this wakes up every receivers which are ready to analyse the addressing characters of the new message. In such a system, the inter-characters space must be smaller than the idle time. Address Mark Detection Receiver wakes up by Address Mark detection when it received a "1" as the most significant bit of a word, thus indicating that the message is an address. The reception of this particular word wakes up the receiver, resets the RWU bit and sets the RDRF bit, which allows the receiver to receive this word normally and to use it as an address word. This feature is useful in a multiprocessor system when the most significant bit of each character (except for the break character) is reserved for Address Detection. As soon as the receivers reTable 23. Character Formats
M bit 0 1 PCE bit 0 1 0 1 Character format | SB | 8 bit data | STB | | SB | 7-bit data | PB | STB | | SB | 9-bit data | STB | | SB | 8-bit data | PB | STB |
Legend: SB = Start Bit, STB = Stop Bit, PB = Parity Bit Even parity: The parity bit is calculated to obtain an even number of "1s" inside the character made of the 7 or 8 LSB bits (depending on whether M is equal to 0 or 1) and the parity bit. Example: data = 00110101; 4 bits set => parity bit will be 0 if even parity is selected (PS bit = 0). Odd parity: The parity bit is calculated to obtain an odd number of "1s" inside the character made of the 7 or 8 LSB bits (depending on whether M is equal to 0 or 1) and the parity bit. Example: data = 00110101; 4 bits set => parity bit will be 1 if odd parity is selected (PS bit = 1). Transmission mode: If the PCE bit is set then the MSB bit of the data written in the data register is not transmitted but is changed by the parity bit. Reception mode: If the PCE bit is set then the interface checks if the received data byte has an even number of "1s" if even parity is selected (PS = 0) or an odd number of "1s" if odd parity is selected (PS = 1). If the parity check fails, the PE flag is set in the SCISR register and an interrupt is generated if PCIE is set in the SCICR1 register.
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LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) 10.7.6 Low Power Modes 10.7.7 Interrupts
M ode WAIT Description No effect on SCI. SCI interrupts cause the device to exit from Wait mode. SCI registers are frozen. In Halt mode, the SCI stops transmitting/receiving until Halt mode is exited. Interrupt Event Enable Exit Event Control from Flag Bit Wait TIE TCIE Exit from Halt
H ALT
Transmit Data Register TD RE Empty Transmission ComTC plete Received Data Ready R DRF to be Read Overrun Error or LIN OR / Synch Error Detected LHE Idle Line Detected IDLE Parity Error PE LIN Header Detection LHDF
RIE ILIE PIE LHIE
Yes
No
The SCI interrupt events are connected to the same interrupt vector (see Interrupts chapter). These events generate an interrupt if the corresponding Enable Control Bit is set and the interrupt mask in the CC register is reset (RIM instruction).
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LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) 10.7.8 SCI Mode Register Description STATUS REGISTER (SCISR) Bit 3 = OR Overrun error Read Only The OR bit is set by hardware when the word curReset Value: 1100 0000 (C0h) rently being received in the shift register is ready to be transferred into the RDR register whereas 7 0 RDRF is still set. An interrupt is generated if RIE = 1 in the SCICR2 register. It is cleared by a 1) 1) 1) 1) TDRE TC RDRF IDLE OR NF FE PE software sequence (an access to the SCISR register followed by a read to the SCIDR register). 0: No Overrun error Bit 7 = TDRE Transmit data register empty 1: Overrun error detected This bit is set by hardware when the content of the TDR register has been transferred into the shift Note: When this bit is set, RDR register contents register. An interrupt is generated if the TIE = 1 in will not be lost but the shift register will be overwritthe SCICR2 register. It is cleared by a software seten. quence (an access to the SCISR register followed by a write to the SCIDR register). 0: Data is not transferred to the shift register Bit 2 = NF Character Noise flag 1: Data is transferred to the shift register This bit is set by hardware when noise is detected on a received character. It is cleared by a software sequence (an access to the SCISR register folBit 6 = TC Transmission complete lowed by a read to the SCIDR register). This bit is set by hardware when transmission of a 0: No noise character containing Data is complete. An inter1: Noise is detected rupt is generated if TCIE = 1 in the SCICR2 regisNote: This bit does not generate interrupt as it apter. It is cleared by a software sequence (an acpears at the same time as the RDRF bit which itcess to the SCISR register followed by a write to self generates an interrupt. the SCIDR register). 0: Transmission is not complete 1: Transmission is complete Bit 1 = FE Framing error Note: TC is not set after the transmission of a PreThis bit is set by hardware when a desynchronizaamble or a Break. tion, excessive noise or a break character is detected. It is cleared by a software sequence (an access to the SCISR register followed by a read to Bit 5 = RDRF Received data ready flag the SCIDR register). This bit is set by hardware when the content of the 0: No Framing error RDR register has been transferred to the SCIDR 1: Framing error or break character detected register. An interrupt is generated if RIE = 1 in the Note: This bit does not generate an interrupt as it SCICR2 register. It is cleared by a software seappears at the same time as the RDRF bit which itquence (an access to the SCISR register followed self generates an interrupt. If the word currently by a read to the SCIDR register). being transferred causes both a frame error and 0: Data is not received an overrun error, it will be transferred and only the 1: Received data is ready to be read OR bit will be set. Bit 4 = IDLE Idle line detected This bit is set by hardware when an Idle Line is detected. An interrupt is generated if the ILIE = 1 in the SCICR2 register. It is cleared by a software sequence (an access to the SCISR register followed by a read to the SCIDR register). 0: No Idle Line is detected 1: Idle Line is detected Note: The IDLE bit will not be set again until the RDRF bit has been set itself (that is, a new idle line occurs). Bit 0 = PE Parity error This bit is set by hardware when a byte parity error occurs (if the PCE bit is set) in receiver mode. It is cleared by a software sequence (a read to the status register followed by an access to the SCIDR data register). An interrupt is generated if PIE = 1 in the SCICR1 register. 0: No parity error 1: Parity error detected
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LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) CONTROL REGISTER 1 (SCICR1) Read/Write Bit 3 = WAKE Wake-Up method Reset Value: x000 0000 (x0h) This bit determines the SCI Wake-Up method, it is set or cleared by software. 7 0 0: Idle Line 1: Address Mark R8 T8 SCID M WAKE PCE1) PS PIE Note: If the LINE bit is set, the WAKE bit is deactivated and replaced by the LHDM bit. 1)
This bit has a different function in LIN mode, please refer to the LIN mode register description.
Bit 7 = R8 Receive data bit 8 This bit is used to store the 9th bit of the received word when M = 1. Bit 6 = T8 Transmit data bit 8 This bit is used to store the 9th bit of the transmitted word when M = 1. Bit 5 = SCID Disabled for low power consumption When this bit is set the SCI prescalers and outputs are stopped and the end of the current byte transfer in order to reduce power consumption.This bit is set and cleared by software. 0: SCI enabled 1: SCI prescaler and outputs disabled Bit 4 = M Word length This bit determines the word length. It is set or cleared by software. 0: 1 Start bit, 8 Data bits, 1 Stop bit 1: 1 Start bit, 9 Data bits, 1 Stop bit Note: The M bit must not be modified during a data transfer (both transmission and reception).
Bit 2 = PCE Parity control enable This bit is set and cleared by software. It selects the hardware parity control (generation and detection for byte parity, detection only for LIN parity). 0: Parity control disabled 1: Parity control enabled Bit 1 = PS Parity selection This bit selects the odd or even parity when the parity generation/detection is enabled (PCE bit set). It is set and cleared by software. The parity will be selected after the current byte. 0: Even parity 1: Odd parity Bit 0 = PIE Parity interrupt enable This bit enables the interrupt capability of the hardware parity control when a parity error is detected (PE bit set). The parity error involved can be a byte parity error (if bit PCE is set and bit LPE is reset) or a LIN parity error (if bit PCE is set and bit LPE is set). 0: Parity error interrupt disabled 1: Parity error interrupt enabled
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LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) CONTROL REGISTER 2 (SCICR2) 1: Receiver is enabled and begins searching for a Read/Write start bit Reset Value: 0000 0000 (00 h) Bit 1 = RWU Receiver wake-up 7 0 This bit determines if the SCI is in mute mode or not. It is set and cleared by software and can be TIE TCIE RIE ILIE TE RE RWU1) SBK1) cleared by hardware when a wake-up sequence is recognized. 1) 0: Receiver in active mode This bit has a different function in LIN mode, please 1: Receiver in mute mode refer to the LIN mode register description. Notes: Bit 7 = TIE Transmitter interrupt enable This bit is set and cleared by software. Before selecting Mute mode (by setting the RWU 0: Interrupt is inhibited bit) the SCI must first receive a data byte, other1: In SCI interrupt is generated whenever wise it cannot function in Mute mode with wakeTDRE = 1 in the SCISR register up by Idle line detection. In Address Mark Detection Wake-Up configuraBit 6 = TCIE Transmission complete interrupt enation (WAKE bit = 1) the RWU bit cannot be modble ified by software while the RDRF bit is set. This bit is set and cleared by software. 0: Interrupt is inhibited Bit 0 = SBK Send break 1: An SCI interrupt is generated whenever TC = 1 This bit set is used to send break characters. It is in the SCISR register set and cleared by software. 0: No break character is transmitted Bit 5 = RIE Receiver interrupt enable 1: Break characters are transmitted This bit is set and cleared by software. Note: If the SBK bit is set to "1" and then to "0", the 0: Interrupt is inhibited transmitter will send a BREAK word at the end of 1: An SCI interrupt is generated whenever OR = 1 the current word. or RDRF = 1 in the SCISR register Bit 4 = ILIE Idle line interrupt enable This bit is set and cleared by software. 0: Interrupt is inhibited 1: An SCI interrupt is generated whenever IDLE = 1 in the SCISR register. Bit 3 = TE Transmitter enable This bit enables the transmitter. It is set and cleared by software. 0: Transmitter is disabled 1: Transmitter is enabled Notes: During transmission, a "0" pulse on the TE bit ("0" followed by "1") sends a preamble (idle line) after the current word. When TE is set there is a 1 bit-time delay before the transmission starts. Bit 2 = RE Receiver enable This bit enables the receiver. It is set and cleared by software. 0: Receiver is disabled in the SCISR register DATA REGISTER (SCIDR) Read/Write Reset Value: Undefined Contains the Received or Transmitted data character, depending on whether it is read from or written to.
7
DR7 DR6 DR5 DR4 DR3 DR2 DR1
0
DR0
The Data register performs a double function (read and write) since it is composed of two registers, one for transmission (TDR) and one for reception (RDR). The TDR register provides the parallel interface between the internal bus and the output shift register (see Figure 1). The RDR register provides the parallel interface between the input shift register and the internal bus (see Figure 1).
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LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) BAUD RATE REGISTER (SCIBRR) TR dividing factor Read/Write 1 Reset Value: 0000 0000 (00h)
2 7
SCP1 SCP0 SCT2 SCT1 SCT0 SCR2
SCT2
SC T1 0
SCT0 0 1 0 1 0 1 0 1
0
SCR1 SCR0
4 8 16 32 64 128
0 1 0 1 1
Note: When LIN slave mode is disabled, the SCIBRR register controls the conventional baud rate generator. Bits 7:6 = SCP[1:0] First SCI Prescaler These 2 prescaling bits allow several standard clock division ranges:
PR Prescaling factor 1 3 4 13 SCP1 0 1 SCP0 0 1 0 1
Bits 2:0 = SCR[2:0] SCI Receiver rate divider These 3 bits, in conjunction with the SCP[1:0] bits define the total division applied to the bus clock to yield the receive rate clock in conventional Baud Rate Generator mode.
RR dividing factor 1 2 4 8 16 32 64 128 1 1 0 1 0 SCR2 SC R1 0 S CR0 0 1 0 1 0 1 0 1
Bits 5:3 = SCT[2:0] SCI Transmitter rate divisor These 3 bits, in conjunction with the SCP1 and SCP0 bits define the total division applied to the bus clock to yield the transmit rate clock in conventional Baud Rate Generator mode.
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LINSCITM SERIAL COMMUNICATION INTERFACE (SCI Mode) (cont'd) EXTENDED RECEIVE PRESCALER DIVISION EXTENDED TRANSMIT PRESCALER DIVISION REGISTER (SCIERPR) REGISTER (SCIETPR) Read/Write Read/Write Reset Value: 0000 0000 (00 h) Reset Value:0000 0000 (00 h)
7 0 7
ETPR 7 ETPR 6 ETPR 5 ETPR 4 ETPR 3 ETPR 2
0
ETPR ETPR 1 0
ERPR ERPR ERPR ERPR ERPR ERPR ERPR ERPR 7 6 5 4 3 2 1 0
Bits 7:0 = ERPR[7:0] 8-bit Extended Receive Prescaler Register The extended Baud Rate Generator is activated when a value other than 00h is stored in this register. The clock frequency from the 16 divider (see Figure 3) is divided by the binary factor set in the SCIERPR register (in the range 1 to 255). The extended baud rate generator is not active after a reset.
Bits 7:0 = ETPR[7:0] 8-bit Extended Transmit Prescaler Register The extended Baud Rate Generator is activated when a value other than 00h is stored in this register. The clock frequency from the 16 divider (see Figure 3) is divided by the binary factor set in the SCIETPR register (in the range 1 to 255). The extended baud rate generator is not active after a reset. Note: In LIN slave mode, the Conventional and Extended Baud Rate Generators are disabled.
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) 10.7.9 LIN Mode - Functional Description. Slave The block diagram of the Serial Control Interface, Set the LSLV bit in the SCICR3 register to enter in LIN slave mode is shown in Figure 5. LIN slave mode. In this case, setting the SBK bit will have no effect. It uses six registers: In LIN Slave mode the LIN baud rate generator is 3 control registers: SCICR1, SCICR2 and selected instead of the Conventional or Extended SCICR3 Prescaler. The LIN baud rate generator is com 2 status registers: the SCISR register and the mon to the transmitter and the receiver. LHLR register mapped at the SCIERPR address Then the baud rate can be programmed using A baud rate register: LPR mapped at the SCILPR and LPRF registers. BRR address and an associated fraction register Note: It is mandatory to set the LIN configuration LPFR mapped at the SCIETPR address first before programming LPR and LPRF, because The bits dedicated to LIN are located in the the LIN configuration uses a different baud rate SCICR3. Refer to the register descriptions in Secgenerator from the standard one. tion 0.1.10 for the definitions of each bit. 10.7.9.1 Entering LIN Mode 10.7.9.2 LIN Transmission To use the LINSCI in LIN mode the following conIn LIN mode the same procedure as in SCI mode figuration must be set in SCICR3 register: has to be applied for a LIN transmission. Clear the M bit to configure 8-bit word length. To transmit the LIN Header the proceed as fol Set the LINE bit. lows : Master First set the SBK bit in the SCICR2 register to start transmitting a 13-bit LIN Synch Break To enter master mode the LSLV bit must be reset In this case, setting the SBK bit will send 13 low reset the SBK bit bits. Load the LIN Synch Field (0x55) in the SCIDR Then the baud rate can programmed using the register to request Synch Field transmission SCIBRR, SCIERPR and SCIETPR registers. Wait until the SCIDR is empty (TDRE bit set in In LIN master mode, the Conventional and / or Exthe SCISR register) tended Prescaler define the baud rate (as in stand Load the LIN message Identifier in the SCIDR ard SCI mode) register to request Identifier transmission.
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) Figure 80. LIN Characters 8-bit Word length (M bit is reset) Next Data Character Next Start Stop S t a r t Bit B i t Bit0 Bit1 Bit2 B i t 3 B i t 4 Bit5 Bit6 Bit7 B i t Idle Line LIN Synch Break = 13 low bits Start Bit LIN Synch Field Extra Start `1' Bit Data Character
LIN Synch Field Next Start Stop Start Bit Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Bit Bit Measurement for baud rate autosynchronization
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) Figure 81. SCI Block Diagram in LIN Slave Mode
Write Read
(DATA REGISTER) SCIDR
Transmit Data Register (TDR)
Received Data Register (RDR)
TDO
Transmit Shift Register
Receive Shift Register
RDI
SCICR1
R8 T8 SCID M
WAKE PCE
PS
PIE
TRANSMIT CONTROL
WAKE UP UNIT
RECEIVER CONTROL
RECEIVER CLOCK
SCICR2
TIE TCIE RIE ILIE TE RE RWU SBK OR/ TDRE TC RDRF IDLE LHE NF FE
SCISR
PE
SCI INTERRUPT CONTROL TRANSMITTER CLOCK
fCPU
LIN SLAVE BAUD RATE AUTO SYNCHRONIZATION UNIT
SCICR3
LDUM LINE LSLV LASE LHDM LHIE LHDF LSF
SCIBRR
LPR7 LPR0 CONVENTIONAL BAUD RATE GENERATOR + EXTENDED PRESCALER 0
fCPU
/ LDIV
/16
1
LIN SLAVE BAUD RATE GENERATOR
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) 10.7.9.3 LIN Reception Note: In LIN mode the reception of a byte is the same as In LIN slave mode, the FE bit detects all frame error which does not correspond to a break. in SCI mode but the LINSCI has features for handling the LIN Header automatically (identifier deIdentifier Detection (LHDM = 1): tection) or semiautomatically (Synch Break detecThis case is the same as the previous one except tion) depending on the LIN Header detection that the LHDF and the RDRF flags are set only afmode. The detection mode is selected by the ter the entire header has been received (this is LHDM bit in the SCICR3. true whether automatic resynchronization is enaAdditionally, an automatic resynchronization feabled or not). This indicates that the LIN Identifier is ture can be activated to compensate for any clock available in the SCIDR register. deviation, for more details please refer to Section Notes: 0.1.9.5 LIN Baud Rate. During LIN Synch Field measurement, the SCI LIN Header Handling by a Slave state machine is switched off: No characters are Depending on the LIN Header detection method transferred to the data register. the LINSCI will signal the detection of a LIN HeadLIN Slave parity er after the LIN Synch Break or after the Identifier has been successfully received. In LIN Slave mode (LINE and LSLV bits are set) LIN parity checking can be enabled by setting the Note: PCE bit. It is recommended to combine the Header detecIn this case, the parity bits of the LIN Identifier tion function with Mute mode. Putting the LINSCI Field are checked. The identifier character is recin Mute mode allows the detection of Headers only ognized as the third received character after a and prevents the reception of any other characbreak character (included): ters. This mode can be used to wait for the next Header parity bits without being interrupted by the data bytes of the current message in case this message is not relevant for the application. Synch Break Detection (LHDM = 0): When a LIN Synch Break is received: LIN Synch LIN Synch Identifier The RDRF bit in the SCISR register is set. It inField Break Field dicates that the content of the shift register is transferred to the SCIDR register, a value of 0x00 is expected for a Break. The bits involved are the two MSB positions (7th and 8th bits if M = 0; 8th and 9th bits if M = 1) of The LHDF flag in the SCICR3 register indicates the identifier character. The check is performed as that a LIN Synch Break Field has been detected. specified by the LIN specification: An interrupt is generated if the LHIE bit in the SCICR3 register is set and the I[1:0] bits are cleared in the CCR register. parity bits stop bit start bit Then the LIN Synch Field is received and measidentifier bits ured. ID0 ID1 ID2 ID3 ID4 ID5 P0 P1 If automatic resynchronization is enabled (LASE bit = 1), the LIN Synch Field is not transIdentifier Field ferred to the shift register: There is no need to clear the RDRF bit. P0= ID0 ID1 ID2 ID4 M=0 If automatic resynchronization is disabled (LAP1= ID1 ID3 ID4 ID5 SE bit = 0), the LIN Synch Field is received as a normal character and transferred to the SCIDR register and RDRF is set.
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) 10.7.9.4 LIN Error Detection edge of the Synch Field. Let us refer to this period deviation as D: LIN Header Error Flag If the LHE flag is set, it means that: The LIN Header Error Flag indicates that an invalid D > 15.625% LIN Header has been detected. When a LIN Header Error occurs: If LHE flag is not set, it means that: The LHE flag is set D < 16.40625% An interrupt is generated if the RIE bit is set and If 15.625% D < 16.40625%, then the flag can the I[1:0] bits are cleared in the CCR register. be either set or reset depending on the dephasing between the signal on the RDI line and the If autosynchronization is enabled (LASE bit = 1), CPU clock. this can mean that the LIN Synch Field is corrupted, and that the SCI is in a blocked state (LSF bit is The second check is based on the measurement set). The only way to recover is to reset the LSF bit of each bit time between both edges of the Synch and then to clear the LHE bit. Field: this checks that each of these bit times is large enough compared to the bit time of the cur The LHE bit is reset by an access to the SCISR rent baud rate. register followed by a read of the SCIDR register. When LHE is set due to this error then the SCI LHE/OVR Error Conditions goes into a blocked state (LSF bit is set). When Auto Resynchronization is disabled (LASE LIN Header Time-out Error bit = 0), the LHE flag detects: When the LIN Identifier Field Detection Method is That the received LIN Synch Field is not equal to used (by configuring LHDM to 1) or when LIN 55h. auto-resynchronization is enabled (LASE bit = 1), That an overrun occurred (as in standard SCI the LINSCI automatically monitors the mode) THEADER_MAX condition given by the LIN protocol. Furthermore, if LHDM is set it also detects that a If the entire Header (up to and including the STOP LIN Header Reception Timeout occurred (only if bit of the LIN Identifier Field) is not received within LHDM is set). the maximum time limit of 57 bit times then a LIN Header Error is signalled and the LHE bit is set in When the LIN auto-resynchronization is enabled the SCISR register. (LASE bit = 1), the LHE flag detects: That the deviation error on the Synch Field is outside the LIN specification which allows up to +/-15.5% of period deviation between the slave and master oscillators. A LIN Header Reception Timeout occurred. If THEADER > THEADER_MAX then the LHE flag is set. Refer to Figure 6. (only if LHDM is set to 1) An overflow during the Synch Field Measurement, which leads to an overflow of the divider registers. If LHE is set due to this error then the SCI goes into a blocked state (LSF bit is set). That an overrun occurred on Fields other than the Synch Field (as in standard SCI mode) Deviation Error on the Synch Field The deviation error is checking by comparing the current baud rate (relative to the slave oscillator) with the received LIN Synch Field (relative to the master oscillator). Two checks are performed in parallel: The first check is based on a measurement between the first falling edge and the last falling Figure 82. LIN Header Reception Timeout
LIN Synch Break
LIN Synch Field
I dentifier Field
THEADER The time-out counter is enabled at each break detection. It is stopped in the following conditions: - A LIN Identifier Field has been received - An LHE error occurred (other than a timeout error). - A software reset of LSF bit (transition from high to low) occurred during the analysis of the LIN Synch Field or If LHE bit is set due to this error during the LIN Synchr Field (if LASE bit = 1) then the SCI goes into a blocked state (LSF bit is set).
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) If LHE bit is set due to this error during Fields other LIN Header Length than LIN Synch Field or if LASE bit is reset then Even if no timeout occurs on the LIN Header, it is the current received Header is discarded and the possible to have access to the effective LIN headSCI searches for a new Break Field. er Length (THEADER) through the LHL register. Note on LIN Header Time-out Limit This allows monitoring at software level the TFRAME_MAX condition given by the LIN protocol. According to the LIN specification, the maximum This feature is only available when LHDM bit = 1 length of a LIN Header which does not cause a or when LASE bit = 1. timeout is equal to 1.4 * (34 + 1) = 49 TBIT_MASTER. Mute Mode and Errors TBIT_MASTER refers to the master baud rate. In mute mode when LHDM bit = 1, if an LHE error When checking this timeout, the slave node is deoccurs during the analysis of the LIN Synch Field synchronized for the reception of the LIN Break or if a LIN Header Time-out occurs then the LHE and Synch fields. Consequently, a margin must be bit is set but it does not wake up from mute mode. allowed, taking into account the worst case: This In this case, the current header analysis is discarded. If needed, the software has to reset LSF bit. occurs when the LIN identifier lasts exactly 10 Then the SCI searches for a new LIN header. TBIT_MASTER periods. In this case, the LIN Break and Synch fields last 49 - 10 = 39TBIT_MASTER peIn mute mode, if a framing error occurs on a data riods. (which is not a break), it is discarded and the FE bit Assuming the slave measures these first 39 bits is not set. with a desynchronized clock of 15.5%. This leads When LHDM bit = 1, any LIN header which reto a maximum allowed Header Length of: spects the following conditions causes a wake-up 39 x (1/0.845) TBIT_MASTER + 10TBIT_MASTER from mute mode: = 56.15 TBIT_SLAVE - A valid LIN Break Field (at least 11 dominant bits followed by a recessive bit) A margin is provided so that the time-out occurs - A valid LIN Synch Field (without deviation error) when the header length is greater than 57 TBIT_SLAVE periods. If it is less than or equal to 57 - A LIN Identifier Field without framing error. Note TBIT_SLAVE periods, then no timeout occurs. that a LIN parity error on the LIN Identifier Field does not prevent wake-up from mute mode. - No LIN Header Time-out should occur during Header reception. Figure 83. LIN Synch Field Measurement
TCPU = CPU period TBR = Baud Rate period TBR = 16.LPR.TCPU
SM = Synch Measurement Register (15 bits) TBR LIN Synch Break Extra `1' LIN Synch Field Start Bit Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Stop Bit Next Start Bit
Measurement = 8.TBR = SM.TCPU LP R(n) LPR = TBR / (16.TCPU) = Rounding (SM / 128) LPR(n+1)
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) 10.7.9.5 LIN Baud Rate mitter are both set to the same value, depending on the LIN Slave baud rate generator: Baud rate programming is done by writing a value in the LPR prescaler or performing an automatic resynchronization as described below. fCPU Automatic Resynchronization Tx = Rx = (16*LDIV) To automatically adjust the baud rate based on measurement of the LIN Synch Field: with: Write the nominal LIN Prescaler value (usually LDIV is an unsigned fixed point number. The mandepending on the nominal baud rate) in the tissa is coded on 8 bits in the LPR register and the LPFR / LPR registers. fraction is coded on 4 bits in the LPFR register. Set the LASE bit to enable the Auto SynchroniIf LASE bit = 1 then LDIV is automatically updated zation Unit. at the end of each LIN Synch Field. When Auto Synchronization is enabled, after each Three registers are used internally to manage the LIN Synch Break, the time duration between five auto-update of the LIN divider (LDIV): falling edges on RDI is sampled on fCPU and the - LDIV_NOM (nominal value written by software at result of this measurement is stored in an internal LPR/LPFR addresses) 15-bit register called SM (not user accessible) (see Figure 7). Then the LDIV value (and its asso- LDIV_MEAS (results of the Field Synch measciated LPFR and LPR registers) are automatically urement) updated at the end of the fifth falling edge. During - LDIV (used to generate the local baud rate) LIN Synch field measurement, the SCI state maThe control and interactions of these registers, exchine is stopped and no data is transferred to the plained in Figure 8 and Figure 9, depend on the data register. LDUM bit setting (LIN Divider Update Method). 10.7.9.6 LIN Slave Baud Rate Generation Note: In LIN mode, transmission and reception are drivAs explained in Figure 8 and Figure 9, LDIV can en by the LIN baud rate generator be updated by two concurrent actions: a transfer Note: LIN Master mode uses the Extended or from LDIV_MEAS at the end of the LIN Sync Field Conventional prescaler register to generate the and a transfer from LDIV_NOM due to a software baud rate. write of LPR. If both operations occur at the same If LINE bit = 1 and LSLV bit = 1 then the Conventime, the transfer from LDIV_NOM has priority. tional and Extended Baud Rate Generators are disabled: the baud rate for the receiver and trans-
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) Figure 84. LDIV Read / Write Operations When LDUM = 0 Write LPR Write LPFR LIN Sync Field Measurement
MANT(7:0) FRAC(3:0)
LDIV_NOM
Write LPR MANT(7:0) FRAC(3:0) LDIV_MEAS Update at end of Synch Field
MANT(7:0) FRAC(3:0) LDIV
Baud Rate Generation
Read LPR
Read LPFR
Figure 85. LDIV Read / Write Operations When LDUM = 1 Write LPR Write LPFR LIN Sync Field Measurement
MANT(7:0) FRAC(3:0)
LDIV_NOM
RDRF = 1 MANT(7:0) FRAC(3:0) LDIV_MEAS Update at end of Synch Field
MANT(7:0) FRAC(3:0) LDIV
Baud Rate Generation
Read LPR
Read LPFR
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) 10.7.9.7 LINSCI Clock Tolerance Consequently, the clock frequency should not vary more than 6/16 (37.5%) within one bit. LINSCI Clock Tolerance when unsynchronized The sampling clock is resynchronized at each start When LIN slaves are unsynchronized (meaning no bit, so that when receiving 10 bits (one start bit, 1 characters have been transmitted for a relatively data byte, 1 stop bit), the clock deviation should long time), the maximum tolerated deviation of the not exceed 3.75%. LINSCI clock is +/-15%. 10.7.9.8 Clock Deviation Causes If the deviation is within this range then the LIN The causes which contribute to the total deviation Synch Break is detected properly when a new reception occurs. are: This is made possible by the fact that masters DTRA: Deviation due to transmitter error. Note: The transmitter can be either a master send 13 low bits for the LIN Synch Break, which or a slave (in case of a slave listening to the can be interpreted as 11 low bits (13 bits -15% = response of another slave). 11.05) by a "fast" slave and then considered as a LIN Synch Break. According to the LIN specifica DMEAS: Error due to the LIN Synch measuretion, a LIN Synch Break is valid when its duration ment performed by the receiver. is greater than tSBRKTS = 10. This means that the DQUANT: Error due to the baud rate quantizaLIN Synch Break must last at least 11 low bits. tion of the receiver. Note: If the period desynchronization of the slave DREC: Deviation of the local oscillator of the is +15% (slave too slow), the character "00h" receiver: This deviation can occur during the which represents a sequence of 9 low bits must reception of one complete LIN message asnot be interpreted as a break character (9 bits + suming that the deviation has been compen15% = 10.35). Consequently, a valid LIN Synch sated at the beginning of the message. break must last at least 11 low bits. DTCL: Deviation due to the transmission line LINSCI Clock Tolerance when Synchronized (generally due to the transceivers) When synchronization has been performed, folAll the deviations of the system should be added lowing reception of a LIN Synch Break, the LINSand compared to the LINSCI clock tolerance: CI, in LIN mode, has the same clock deviation tolDTRA + DMEAS +DQUANT + DREC + DTCL < 3.75% erance as in SCI mode, which is explained below: During reception, each bit is oversampled 16 times. The mean of the 8th, 9th and 10th samples is considered as the bit value. Figure 86.Bit Sampling in Reception Mode
RDI LINE sampled values Sample clock 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
6/16 7/16 One bit time 7/16
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) 10.7.9.9 Error due to LIN Synch measurement Consequently, at a given CPU frequency, the maximum possible nominal baud rate (LPRMIN) The LIN Synch Field is measured over eight bit should be chosen with respect to the maximum toltimes. erated deviation given by the equation: This measurement is performed using a counter DTRA + 2 / (128*LDIVMIN) + 1 / (2*16*LDIVMIN) clocked by the CPU clock. The edge detections + DREC + DTCL < 3.75% are performed using the CPU clock cycle. This leads to a precision of 2 CPU clock cycles for the measurement which lasts 16*8*LDIV clock cyExample: cles. A nominal baud rate of 20Kbits/s at TCPU = 125ns Consequently, this error (DMEAS) is equal to: (8 MHz) leads to LDIVNOM = 25d. 2 / (128*LDIVMIN). LDIVMIN = 25 - 0.15*25 = 21.25 LDIVMIN corresponds to the minimum LIN prescalDMEAS = 2 / (128*LDIVMIN) * 100 = 0.00073% er content, leading to the maximum baud rate, takDQUANT = 1 / (2*16*LDIVMIN) * 100 = 0.0015% ing into account the maximum deviation of +/-15%. 10.7.9.10 Error due to Baud Rate Quantization The baud rate can be adjusted in steps of 1 / (16 * LDIV). The worst case occurs when the "real" baud rate is in the middle of the step. This leads to a quantization error (DQUANT) equal to 1 / (2*16*LDIVMIN). 10.7.9.11 Impact of Clock Deviation on Maximum Baud Rate The choice of the nominal baud rate (LDIVNOM) will influence both the quantization error (DQUANT) and the measurement error (DMEAS). The worst case occurs for LDIVMIN. LIN Slave systems For LIN Slave systems (the LINE and LSLV bits are set), receivers wake up by LIN Synch Break or LIN Identifier detection (depending on the LHDM bit). Hot Plugging Feature for LIN Slave Nodes In LIN Slave Mute Mode (the LINE, LSLV and RWU bits are set) it is possible to hot plug to a network during an ongoing communication flow. In this case the SCI monitors the bus on the RDI line until 11 consecutive dominant bits have been detected and discards all the other bits received.
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) 10.7.10 LIN Mode Register Description framing error is detected (if the stop bit is dominant (0) and at least one of the other bits is recessive STATUS REGISTER (SCISR) (1). It is not set when a break occurs, the LHDF bit Read Only is used instead as a break flag (if the LHDM Reset Value: 1100 0000 (C0h) bit = 0). It is cleared by a software sequence (an access to the SCISR register followed by a read to 7 0 the SCIDR register). 0: No Framing error TDRE TC RDRF IDLE LHE NF FE PE 1: Framing error detected Bits 7:4 = Same function as in SCI mode; please refer to Section 0.1.8 SCI Mode Register Description. Bit 3 = LHE LIN Header Error. During LIN Header this bit signals three error types: The LIN Synch Field is corrupted and the SCI is blocked in LIN Synch State (LSF bit = 1). A timeout occurred during LIN Header reception An overrun error was detected on one of the header field (see OR bit description in Section 0.1.8 SCI Mode Register Description). An interrupt is generated if RIE = 1 in the SCICR2 register. If blocked in the LIN Synch State, the LSF bit must first be reset (to exit LIN Synch Field state and then to be able to clear LHE flag). Then it is cleared by the following software sequence: An access to the SCISR register followed by a read to the SCIDR register. 0: No LIN Header error 1: LIN Header error detected Note: Apart from the LIN Header this bit signals an Overrun Error as in SCI mode (see description in Section 0.1.8 SCI Mode Register Description). Bit 2 = NF Noise flag In LIN Master mode (LINE bit = 1 and LSLV bit = 0), this bit has the same function as in SCI mode; please refer to Section 0.1.8 SCI Mode Register Description. In LIN Slave mode (LINE bit = 1 and LSLV bit = 1) this bit has no meaning. Bit 1 = FE Framing error. In LIN slave mode, this bit is set only when a real Bit 0 = PE Parity error. This bit is set by hardware when a LIN parity error occurs (if the PCE bit is set) in receiver mode. It is cleared by a software sequence (a read to the status register followed by an access to the SCIDR data register). An interrupt is generated if PIE = 1 in the SCICR1 register. 0: No LIN parity error 1: LIN Parity error detected CONTROL REGISTER 1 (SCICR1) Read/Write Reset Value: x000 0000 (x0h)
7
R8 T8 SCID M WAKE PCE PS
0
PIE
Bits 7:3 = Same function as in SCI mode; please refer to Section 0.1.8 SCI Mode Register Description. Bit 2 = PCE Parity control enable. This bit is set and cleared by software. It selects the hardware parity control for LIN identifier parity check. 0: Parity control disabled 1: Parity control enabled When a parity error occurs, the PE bit in the SCISR register is set. Bit 1 = Reserved Bit 0 = Same function as in SCI mode; please refer to Section 0.1.8 SCI Mode Register Description.
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) CONTROL REGISTER 2 (SCICR2) 1: LDIV is updated at the next received character Read/Write (when RDRF = 1) after a write to the LPR regisReset Value: 0000 0000 (00 h) ter Notes: 7 0 - If no write to LPR is performed between the setting of LDUM bit and the reception of the next TIE TCIE RIE ILIE TE RE RWU SBK character, LDIV will be updated with the old value. - After LDUM has been set, it is possible to reset Bits 7:2 Same function as in SCI mode; please rethe LDUM bit by software. In this case, LDIV can fer to Section 0.1.8 SCI Mode Register Descripbe modified by writing into LPR / LPFR registers. tion. Bit 1 = RWU Receiver wake-up. This bit determines if the SCI is in mute mode or not. It is set and cleared by software and can be cleared by hardware when a wake-up sequence is recognized. 0: Receiver in active mode 1: Receiver in mute mode Notes: Mute mode is recommended for detecting only the Header and avoiding the reception of any other characters. For more details, please refer to Section 0.1.9.3 LIN Reception. In LIN slave mode, when RDRF is set, the software can not set or clear the RWU bit. Bit 0 = SBK Send break. This bit set is used to send break characters. It is set and cleared by software. 0: No break character is transmitted 1: Break characters are transmitted Note: If the SBK bit is set to "1" and then to "0", the transmitter will send a BREAK word at the end of the current word. CONTROL REGISTER 3 (SCICR3) Read/Write Reset Value: 0000 0000 (00h)
7
LDUM LINE LSLV LASE LHDM LHIE LHDF
Bits 6:5 = LINE, LSLV LIN Mode Enable Bits. These bits configure the LIN mode:
LIN E 0 1 LSLV x 0 1 Meaning LIN mode disabled LIN Master Mode LIN Slave Mode
The LIN Master configuration enables: The capability to send LIN Synch Breaks (13 low bits) using the SBK bit in the SCICR2 register. The LIN Slave configuration enables: The LIN Slave Baud Rate generator. The LIN Divider (LDIV) is then represented by the LPR and LPFR registers. The LPR and LPFR registers are read/write accessible at the address of the SCIBRR register and the address of the SCIETPR register Management of LIN Headers. LIN Synch Break detection (11-bit dominant). LIN Wake-Up method (see LHDM bit) instead of the normal SCI Wake-Up method. Inhibition of Break transmission capability (SBK has no effect) LIN Parity Checking (in conjunction with the PCE bit) Bit 4 = LASE LIN Auto Synch Enable. This bit enables the Auto Synch Unit (ASU). It is set and cleared by software. It is only usable in LIN Slave mode. 0: Auto Synch Unit disabled 1: Auto Synch Unit enabled. Bit 3 = LHDM LIN Header Detection Method This bit is set and cleared by software. It is only usable in LIN Slave mode. It enables the Header Detection Method. In addition if the RWU bit in the
0
LSF
Bit 7 = LDUM LIN Divider Update Method. This bit is set and cleared by software and is also cleared by hardware (when RDRF = 1). It is only used in LIN Slave mode. It determines how the LIN Divider can be updated by software. 0: LDIV is updated as soon as LPR is written (if no Auto Synchronization update occurs at the same time).
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) SCICR2 register is set, the LHDM bit selects the Figure 87. LSF Bit Set and Clear Wake-Up method (replacing the WAKE bit). 11 dominant bits parity bits 0: LIN Synch Break Detection Method 1: LIN Identifier Field Detection Method Bit 2 = LHIE LIN Header Interrupt Enable This bit is set and cleared by software. It is only usable in LIN Slave mode. 0: LIN Header Interrupt is inhibited. 1: An SCI interrupt is generated whenever LHDF = 1. Bit 1 = LHDF LIN Header Detection Flag This bit is set by hardware when a LIN Header is detected and cleared by a software sequence (an access to the SCISR register followed by a read of the SCICR3 register). It is only usable in LIN Slave mode. 0: No LIN Header detected. 1: LIN Header detected. Notes: The header detection method depends on the LHDM bit: If LHDM = 0, a header is detected as a LIN Synch Break. If LHDM = 1, a header is detected as a LIN Identifier, meaning that a LIN Synch Break Field + a LIN Synch Field + a LIN Identifier Field have been consecutively received. Bit 0 = LSF LIN Synch Field State This bit indicates that the LIN Synch Field is being analyzed. It is only used in LIN Slave mode. In Auto Synchronization Mode (LASE bit = 1), when the SCI is in the LIN Synch Field State it waits or counts the falling edges on the RDI line. It is set by hardware as soon as a LIN Synch Break is detected and cleared by hardware when the LIN Synch Field analysis is finished (see Figure 11). This bit can also be cleared by software to exit LIN Synch State and return to idle mode. 0: The current character is not the LIN Synch Field 1: LIN Synch Field State (LIN Synch Field undergoing analysis)
LSF bit LIN Synch Break LIN Synch Field Identifier Field
LIN DIVIDER REGISTERS LDIV is coded using the two registers LPR and LPFR. In LIN Slave mode, the LPR register is accessible at the address of the SCIBRR register and the LPFR register is accessible at the address of the SCIETPR register. LIN PRESCALER REGISTER (LPR) Read/Write Reset Value: 0000 0000 (00h)
7
LPR7 LPR6 LPR5 LPR4 LPR3 LPR2 LPR1
0
LPR0
LPR[7:0] LIN Prescaler (mantissa of LDIV) These 8 bits define the value of the mantissa of the LIN Divider (LDIV):
LP R[7:0] 00h 01h ... FEh FFh Rounded Mantissa (LDIV) SCI clock disabled 1 ... 254 255
Caution: LPR and LPFR registers have different meanings when reading or writing to them. Consequently bit manipulation instructions (BRES or BSET) should never be used to modify the LPR[7:0] bits, or the LPFR[3:0] bits.
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) LIN PRESCALER FRACTION REGISTER will effectively update LDIV and so the clock gen(LPFR) eration. Read/Write 2. In LIN Slave mode, if the LPR[7:0] register is Reset Value: 00 00 0000 (00h) equal to 00h, the transceiver and receiver input clocks are switched off. 7 0
0 0 0 0 LPFR 3 LPFR 2 LPFR 1 LPFR 0
Bits 7:4 = Reserved. Bits 3:0 = LPFR[3:0] Fraction of LDIV These 4 bits define the fraction of the LIN Divider (LDIV):
LPFR[3:0] 0h 1h ... Eh Fh Fraction (LDIV) 0 1/16 ... 14/16 15/16
Examples of LDIV coding: Example 1: LPR = 27d and LPFR = 12d This leads to: Mantissa (LDIV) = 27d Fraction (LDIV) = 12/16 = 0.75d Therefore LDIV = 27.75d Example 2: LDIV = 25.62d This leads to: LPFR = rounded(16*0.62d) = rounded(9.92d) = 10d = Ah LPR = mantissa (25.620d) = 25d = 1Bh Example 3: LDIV = 25.99d This leads to: LPFR = rounded(16*0.99d) = rounded(15.84d) = 16d
1. When initializing LDIV, the LPFR register must be written first. Then, the write to the LPR register
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont'd) LIN HEADER LENGTH REGISTER (LHLR) LH L[1:0] Read Only 0h Reset Value: 0000 0000 (00 h).
1h 7
LHL7 LHL6 LHL5 LHL4 LHL3 LHL2 LHL1
Fraction (57 - THEADER) 0 1/4 1/2 3/4
0
LHL0
2h 3h
Note: In LIN Slave mode when LASE = 1 or LHDM = 1, the LHLR register is accessible at the address of the SCIERPR register. Otherwise this register is always read as 00h. Bits 7:0 = LHL[7:0] LIN Header Length. This is a read-only register, which is updated by hardware if one of the following conditions occurs: - After each break detection, it is loaded with "FFh". - If a timeout occurs on THEADER, it is loaded with 00h. - After every successful LIN Header reception (at the same time than the setting of LHDF bit), it is loaded with a value (LHL) which gives access to the number of bit times of the LIN header length (THEADER). The coding of this value is explained below: LHL Coding: THEADER_MAX = 57 LHL(7:2) represents the mantissa of (57 - THEADER) LHL(1:0) represents the fraction (57 - THEADER)
LHL[7:2] 0h 1h ... 39h 3Ah 3Bh ... 3Eh 3Fh Mantissa (57 - T H E A D E R ) 0 1 ... 56 57 58 ... 62 63 Mantissa (THEADER) 57 56 ... 1 0 Never Occurs ... Never Occurs Initial value
Example of LHL coding: Example 1: LHL = 33h = 001100 11b LHL(7:3) = 1100b = 12d LHL(1:0) = 11b = 3d This leads to: Mantissa (57 - THEADER) = 12d Fraction (57 - THEADER) = 3/4 = 0.75 Therefore: (57 - THEADER) = 12.75d and THEADER = 44.25d Example 2: 57 - THEADER = 36.21d LHL(1:0) = rounded(4*0.21d) = 1d LHL(7:2) = Mantissa (36.21d) = 36d = 24h Therefore LHL(7:0) = 10010001 = 91h Example 3: 57 - THEADER = 36.90d LHL(1:0) = rounded(4*0.90d) = 4d The carry must be propagated to the matissa: LHL(7:2) = Mantissa (36.90d) + 1 = 37d = Therefore LHL(7:0) = 10110000 = A0h
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master/Slave) (Cont'd)
Table 24. LINSCI1 Register Map and Reset Values
Addr. (Hex. ) 48 49 Register Name SCI1SR Reset Value SCI1DR Reset Value SCI1BRR LPR (LIN Slave Mode) Reset Value SCI1CR1 Reset Value SCI1CR2 Reset Value SCI1CR3 Reset Value SCI1ERPR LHLR (LIN Slave Mode) Reset Value SCI1ETPR LPFR (LIN Slave Mode) Reset Value 7 TDR E 1 DR7 S CP1 LP R7 0 R8 x TIE 0 LDUM 0 ERPR7 LHL7 0 ETPR7 0 0 6 TC 1 DR6 SC P0 LPR 6 0 T8 0 TCIE 0 LINE 0 ERPR6 LH L6 0 ETPR6 0 0 5 RDR F 0 DR5 SCT2 LPR5 0 SCID 0 RIE 0 LSLV 0 ERPR5 LHL5 0 ETPR5 0 0 4 IDLE 0 DR4 S CT 1 LP R4 0 M 0 ILIE 0 LAS E 0 ERPR4 LHL4 0 ETPR4 0 0 3 OR/LHE 0 DR3 SCT0 LPR3 0 W AKE 0 TE 0 LH DM 0 ERPR3 LHL3 0 ETPR3 LPFR3 0 2 NF 0 DR2 SCR2 LPR2 0 PCE 0 RE 0 LHIE 0 ERPR 2 LHL2 0 ETPR 2 LPFR2 0 1 FE 0 DR1 S CR1 LP R1 0 PS 0 RWU 0 LH DF 0 ERPR1 LHL1 0 ETPR1 LPFR1 0 0 PE 0 DR0 SCR 0 LPR 0 0 PIE 0 SBK 0 LSF 0 ERPR0 LHL0 0 ETPR0 LPFR0 0
4A
4B 4C 4D
4E
4F
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10.8 LINSCI SERIAL COMMUNICATION INTERFACE (LIN Master Only) 10.8.1 Introduction The Serial Communications Interface (SCI) offers a flexible means of full-duplex data exchange with external equipment requiring an industry standard NRZ asynchronous serial data format. The SCI offers a very wide range of baud rates using two baud rate generator systems. 10.8.2 Main Features Full duplex, asynchronous communications NRZ standard format (Mark/Space) Dual baud rate generator systems Independently programmable transmit and receive baud rates up to 500K baud. Programmable data word length (8 or 9 bits) Receive buffer full, Transmit buffer empty and End of Transmission flags 2 receiver wake-up modes: Address bit (MSB) Idle line Muting function for multiprocessor configurations Separate enable bits for Transmitter and Receiver 4 error detection flags: Overrun error Noise error Frame error Parity error 5 interrupt sources with flags: Transmit data register empty Transmission complete Receive data register full Idle line received Overrun error detected Transmitter clock output Parity control: Transmits parity bit Checks parity of received data byte Reduced power consumption mode LIN Synch Break send capability 10.8.3 General Description The interface is externally connected to another device by three pins (see Figure 88 on page 153). Any SCI bidirectional communication requires a minimum of two pins: Receive Data In (RDI) and Transmit Data Out (TDO): SCLK: Transmitter clock output. This pin outputs the transmitter data clock for synchronous transmission (no clock pulses on start bit and stop bit, and a software option to send a clock pulse on the last data bit). This can be used to control peripherals that have shift registers (e.g. LCD drivers). The clock phase and polarity are software programmable. TDO: Transmit Data Output. When the transmitter is disabled, the output pin returns to its I/O port configuration. When the transmitter is enabled and nothing is to be transmitted, the TDO pin is at high level. RDI: Receive Data Input is the serial data input. Oversampling techniques are used for data recovery by discriminating between valid incoming data and noise. Through these pins, serial data is transmitted and received as frames comprising: An Idle Line prior to transmission or reception A start bit A data word (8 or 9 bits) least significant bit first A Stop bit indicating that the frame is complete. This interface uses two types of baud rate generator: A conventional type for commonly-used baud rates, An extended type with a prescaler offering a very wide range of baud rates even with non-standard oscillator frequencies.
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) Figure 88. SCI Block Diagram
Write Read
(DATA REGISTER) SCIDR
Transmit Data Register (TDR) TD O Transmit Shift Register R DI
LINE
Received Data Register (RDR)
Received Shift Register
-
-
CLKEN CPOL CPHA LBCL
SCICR3
CLOCK EXTRACTION
SCLK
PHASE AND POLARITY CONTROL
R8 T8 SCID
M
WAKE PCE
PS
PIE
SCICR1
TRANSMIT CONTROL
WAKE UP UNIT
RECEIVER CONTROL
RECEIVER CLOCK
SC ICR2
TIE TCIE RIE ILIE TE RE RWU SBK TDRE TC RDRF IDLE OR NF FE
SCISR
PE
SCI INTERRUPT CONTROL TRANSMITTER CLOCK TRANSMITTER RATE
f C PU
CONTROL
/16
/PR SCIBRR
SCP1 SCP0 SCT2 SCT1 SCT0 SCR2 SCR1SCR0
RECEIVER RATE CONTROL CONVENTIONAL BAUD RATE GENERATOR
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) 10.8.4 Functional Description 10.8.4.1 Serial Data Format The block diagram of the Serial Control Interface, Word length may be selected as being either 8 or 9 is shown in Figure 88 on page 153. It contains sevbits by programming the M bit in the SCICR1 regen dedicated registers: ister (see Figure 89). Three control registers (SCICR1, SCICR2 and The TDO pin is in low state during the start bit. SCICR3) The TDO pin is in high state during the stop bit. A status register (SCISR) An Idle character is interpreted as an entire frame A baud rate register (SCIBRR) of "1"s followed by the start bit of the next frame which contains data. An extended prescaler receiver register (SCIERP R) A Break character is interpreted on receiving "0"s for some multiple of the frame period. At the end of An extended prescaler transmitter register (SCIthe last break frame the transmitter inserts an exETPR) tra "1" bit to acknowledge the start bit. Refer to the register descriptions in Section Transmission and reception are driven by their 10.7.8for the definitions of each bit. own baud rate generator. Figure 89. Word Length Programming 9-bit Word length (M bit is set) Data Frame
Start Bit CLO CK Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Possible Parity Bit Bit8 ** Start Bit Extra '1' Start Bit
Next Data Frame
Next S t o p Start Bit Bit
Idle Frame Break Frame
** LBCL bit controls last data clock pulse
8-bit Word length (M bit is reset)
Data Frame
Start Bit Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Possible Parity Bit Bit7 Stop Bit
Next Data Frame
Next Start Bit
CLOCK
**** **
Idle Frame Break Frame
Start Bit Extra Start Bit '1' ** LBCL bit controls last data clock pulse
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) 10.8.4.2 Transmitter When a frame transmission is complete (after the stop bit or after the break frame) the TC bit is set The transmitter can send data words of either 8 or and an interrupt is generated if the TCIE is set and 9 bits depending on the M bit status. When the M the I bit is cleared in the CCR register. bit is set, word length is 9 bits and the 9th bit (the Clearing the TC bit is performed by the following MSB) has to be stored in the T8 bit in the SCICR1 software sequence: register. 1. An access to the SCISR register When the transmit enable bit (TE) is set, the data 2. A write to the SCIDR register in the transmit shift register is output on the TDO Note: The TDRE and TC bits are cleared by the pin and the corresponding clock pulses are output same software sequence. on the SCLK pin. Character Transmission Break Characters During an SCI transmission, data shifts out least Setting the SBK bit loads the shift register with a significant bit first on the TDO pin. In this mode, break character. The break frame length depends the SCIDR register consists of a buffer (TDR) beon the M bit (see Figure 89). tween the internal bus and the transmit shift regisAs long as the SBK bit is set, the SCI send break ter (see Figure 89). frames to the TDO pin. After clearing this bit by Procedure software the SCI insert a logic 1 bit at the end of the last break frame to guarantee the recognition Select the M bit to define the word length. of the start bit of the next frame. Select the desired baud rate using the SCIBRR Idle Characters and the SCIETPR registers. Setting the TE bit drives the SCI to send an idle Set the TE bit to send an idle frame as first transframe before the first data frame. mission. Clearing and then setting the TE bit during a trans Access the SCISR register and write the data to mission sends an idle frame after the current word. send in the SCIDR register (this sequence clears Note: Resetting and setting the TE bit causes the the TDRE bit). Repeat this sequence for each data in the TDR register to be lost. Therefore the data to be transmitted. best time to toggle the TE bit is when the TDRE bit Clearing the TDRE bit is always performed by the is set, that is, before writing the next byte in the following software sequence: SCIDR. 1. An access to the SCISR register 2. A write to the SCIDR register LIN Transmission The TDRE bit is set by hardware and it indicates: The same procedure has to be applied for LIN Master transmission with the following differences: The TDR register is empty. Clear the M bit to configure 8-bit word length. The data transfer is beginning. Set the LINE bit to enter LIN master mode. In this The next data can be written in the SCIDR regiscase, setting the SBK bit sends 13 low bits. ter without overwriting the previous data. This flag generates an interrupt if the TIE bit is set and the I bit is cleared in the CCR register. When a transmission is taking place, a write instruction to the SCIDR register stores the data in the TDR register and which is copied in the shift register at the end of the current transmission. When no transmission is taking place, a write instruction to the SCIDR register places the data directly in the shift register, the data transmission starts, and the TDRE bit is immediately set.
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) 10.8.4.3 Receiver Overrun Error The SCI can receive data words of either 8 or 9 An overrun error occurs when a character is received when RDRF has not been reset. Data canbits. When the M bit is set, word length is 9 bits not be transferred from the shift register to the and the MSB is stored in the R8 bit in the SCICR1 RDR register until the RDRF bit is cleared. register. Character reception When a overrun error occurs: During a SCI reception, data shifts in least signifi The OR bit is set. cant bit first through the RDI pin. In this mode, the The RDR content is not lost. SCIDR register consists or a buffer (RDR) be The shift register is overwritten. tween the internal bus and the received shift register (see Figure 88 on page 153). An interrupt is generated if the RIE bit is set and the I bit is cleared in the CCR register. Procedure The OR bit is reset by an access to the SCISR reg Select the M bit to define the word length. ister followed by a SCIDR register read operation. Select the desired baud rate using the SCIBRR Noise Error and the SCIERPR registers. Oversampling techniques are used for data recov Set the RE bit, this enables the receiver which ery by discriminating between valid incoming data begins searching for a start bit. and noise. When a character is received: When noise is detected in a frame: The RDRF bit is set. It indicates that the content The NF is set at the rising edge of the RDRF bit. of the shift register is transferred to the RDR. Data is transferred from the Shift register to the An interrupt is generated if the RIE bit is set and SCIDR register. the I bit is cleared in the CCR register. No interrupt is generated. However this bit rises The error flags can be set if a frame error, noise at the same time as the RDRF bit which itself or an overrun error has been detected during regenerates an interrupt. ception. The NF bit is reset by a SCISR register read operClearing the RDRF bit is performed by the following ation followed by a SCIDR register read operation. software sequence done by: Framing Error 1. An access to the SCISR register A framing error is detected when: 2. A read to the SCIDR register. The stop bit is not recognized on reception at the The RDRF bit must be cleared before the end of the expected time, following either a de-synchronireception of the next character to avoid an overrun zation or excessive noise. error. A break is received. Break Character When the framing error is detected: When a break character is received, the SCI handles it as a framing error. the FE bit is set by hardware Idle Character Data is transferred from the Shift register to the SCIDR register. When an idle frame is detected, there is the same procedure as a data received character plus an in No interrupt is generated. However this bit rises terrupt if the ILIE bit is set and the I bit is cleared in at the same time as the RDRF bit which itself the CCR register. generates an interrupt. The FE bit is reset by a SCISR register read operation followed by a SCIDR register read operation.
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) Figure 90. SCI Baud Rate and Extended Prescaler Block Diagram
TRANSMITTER CLOCK EXTENDED PRESCALER TRANSMITTER RATE CONTROL
SCIETPR
EXTENDED TRANSMITTER PRESCALER REGISTER
SC IERP R
EXTENDED RECEIVER PRESCALER REGISTER RECEIVER CLOCK EXTENDED PRESCALER RECEIVER RATE CONTROL EXTENDED PRESCALER
fCPU
TRANSMITTER RATE CONTROL
/16
/PR SCIBRR
SCP1 SCP0 SCT2 SCT1 SCT0 SCR2 SCR1SCR0
RECEIVER RATE CONTROL CONVENTIONAL BAUD RATE GENERATOR
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) other than zero. The baud rates are calculated as 10.8.4.4 Conventional Baud Rate Generation follows: The baud rates for the receiver and transmitter (Rx and Tx) are set independently and calculated as fCPU f CPU follows Rx = Tx = : 16*ERPR*(PR*RR) 16*ETPR*(PR*TR) fCPU fCPU Rx = Tx = with: (16*PR)*RR (16*PR)*TR ETPR = 1, ..., 255 (see SCIETPR register) with: ERPR = 1, ..., 255 (see SCIERPR register) PR = 1, 3, 4 or 13 (see SCP[1:0] bits) 10.8.4.6 Receiver Muting and Wake-up Feature TR = 1, 2, 4, 8, 16, 32, 64, 128 In multiprocessor configurations it is often desirable that only the intended message recipient (see SCT[2:0] bits) should actively receive the full message contents, RR = 1, 2, 4, 8, 16, 32, 64, 128 thus reducing redundant SCI service overhead for (see SCR[2:0] bits) all non addressed receivers. All these bits are in the SCIBRR register. The non addressed devices may be placed in sleep mode by means of the muting function. Example: If fCPU is 8 MHz (normal mode) and if PR = 13 and TR = RR = 1, the transmit and reSetting the RWU bit by software puts the SCI in ceive baud rates are 38400 baud. sleep mode: Note: The baud rate registers MUST NOT be All the reception status bits cannot be set. changed while the transmitter or the receiver is enAll the receive interrupts are inhibited. abled. A muted receiver may be awakened by one of the 10.8.4.5 Extended Baud Rate Generation following two ways: The extended prescaler option gives a very fine by Idle Line detection if the WAKE bit is reset, tuning on the baud rate, using a 255 value prescal by Address Mark detection if the WAKE bit is set. er, whereas the conventional Baud Rate Generator retains industry standard software compatibiliReceiver wakes-up by Idle Line detection when ty. the Receive line has recognized an Idle Frame. Then the RWU bit is reset by hardware but the The extended baud rate generator block diagram IDLE bit is not set. is described in the Figure 90. Receiver wakes-up by Address Mark detection The output clock rate sent to the transmitter or to when it received a "1" as the most significant bit of the receiver is the output from the 16 divider divida word, thus indicating that the message is an aded by a factor ranging from 1 to 255 set in the SCIdress. The reception of this particular word wakes ERPR or the SCIETPR register. up the receiver, resets the RWU bit and sets the Note: The extended prescaler is activated by setRDRF bit, which allows the receiver to receive this ting the SCIETPR or SCIERPR register to a value word normally and to use it as an address word.
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) even number of "1s" if even parity is selected 10.8.4.7 Parity control (PS = 0) or an odd number of "1s" if odd parity is Parity control (generation of parity bit in transmisselected (PS = 1). If the parity check fails, the PE sion and parity checking in reception) can be enaflag is set in the SCISR register and an interrupt is bled by setting the PCE bit in the SCICR1 register. generated if PIE is set in the SCICR1 register. Depending on the frame length defined by the M bit, the possible SCI frame formats are as listed in Table 24. 10.8.5 Low Power Modes Table 25. Frame Formats
M bit 0 1 PCE bit 0 1 0 1 SCI frame | SB | 8 bit data | STB | | SB | 7-bit data | PB | STB | | SB | 9-bit data | STB | | SB | 8-bit data PB | STB | M ode WAIT Description No effect on SCI. SCI interrupts cause the device to exit from Wait mode. SCI registers are frozen. In Halt mode, the SCI stops transmitting/receiving until Halt mode is exited.
H AL T
Legend: SB: Start Bit STB: Stop Bit PB: Parity Bit Note: In case of wake up by an address mark, the MSB bit of the data is taken into account and not the parity bit Even parity: The parity bit is calculated to obtain an even number of "1s" inside the frame made of the 7 or 8 LSB bits (depending on whether M is equal to 0 or 1) and the parity bit. Example: data = 00110101; 4 bits set => parity bit is 0 if even parity is selected (PS bit = 0). Odd parity: The parity bit is calculated to obtain an odd number of "1s" inside the frame made of the 7 or 8 LSB bits (depending on whether M is equal to 0 or 1) and the parity bit. Example: data = 00110101; 4 bits set => parity bit is 1 if odd parity is selected (PS bit = 1). Transmission mode: If the PCE bit is set then the MSB bit of the data written in the data register is not transmitted but is changed by the parity bit. Reception mode: If the PCE bit is set then the interface checks if the received data byte has an
10.8.6 Interrupts
Interrupt Event Enable Exit Event Control from Flag Bit Wait TIE TCIE Yes RIE ILIE PIE No Exit from Halt
Transmit Data Register TD RE Empty Transmission ComTC plete Received Data Ready R DRF to be Read Overrun Error DetectOR ed Idle Line Detected IDLE Parity Error PE
The SCI interrupt events are connected to the same interrupt vector. These events generate an interrupt if the corresponding Enable Control Bit is set and the interrupt mask in the CC register is reset (RIM instruction).
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) 10.8.7 SCI Synchronous Transmission These options allow the user to serially control peripherals which consist of shift registers, without The SCI transmitter allows the user to control a losing any functions of the SCI transmitter which one way synchronous serial transmission. The can still talk to other SCI receivers. These options SCLK pin is the output of the SCI transmitter clock. do not affect the SCI receiver which is independNo clock pulses are sent to the SCLK pin during ent from the transmitter. start bit and stop bit. Depending on the state of the Note: The SCLK pin works in conjunction with the LBCL bit in the SCICR3 register, clock pulses are TDO pin. When the SCI transmitter is disabled (TE or are not be generated during the last valid data and RE = 0), the SCLK and TDO pins go into high bit (address mark). The CPOL bit in the SCICR3 impedance state. register allows the user to select the clock polarity, and the CPHA bit in the SCICR3 register allows Note: The LBCL, CPOL and CPHA bits have to be the user to select the phase of the external clock selected before enabling the transmitter to ensure (see Figure 91, Figure 92 and Figure 93). that the clock pulses function correctly. These bits During idle, preamble and send break, the external should not be changed while the transmitter is enabled. SCLK clock is not activated. Figure 91. SCI Example of Synchronous and Asynchronous Transmission
RDI TDO SCI SCLK Output port
Data out Data in
Asynchronous (e.g. modem)
Data in Clock Enable
Synchronous (e.g. shift register)
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) Figure 92. SCI Data Clock Timing Diagram (M = 0)
Idle or preceding Start transmission Clock (CPOL=0, CPHA=0) Clock (CPOL=0, CPHA=1)
Idle or next
M = 0 (8 data bits)
Stop
transmission
* *
Clock (CPOL=1, CPHA=0)
* *
0 1 2 3 4 5 6 7
Clock (CPOL=1, CPHA=1)
Data Start
LSB
MSB Stop * LBCL bit controls last data clock pulse
Figure 93. SCI Data Clock Timing Diagram (M = 1)
Idle or preceding Start transmission Clock (CPOL=0, CPHA=0) Clock (CPOL=0, CPHA=1) M = 1 (9 data bits) Stop Idle or next transmission
* *
Clock (CPOL=1, CPHA=0)
* *
0 1 2 3 4 5 6 7 8
Clock (CPOL=1, CPHA=1)
Data Start
LSB
MSB S top * LBCL bit controls last data clock pulse
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) 10.8.8 Register Description Note: The IDLE bit is not be set again until the RDRF bit has been set itself (that is, a new idle line STATUS REGISTER (SCISR) occurs). Read Only Reset Value: 1100 0000 (C0h) Bit 3 = OR Overrun error. 7 0 This bit is set by hardware when the word currently being received in the shift register is ready to be TDRE TC RDRF IDLE OR NF FE PE transferred into the RDR register while RDRF = 1. An interrupt is generated if RIE = 1 in the SCICR2 register. It is cleared by a software sequence (an Bit 7 = TDRE Transmit data register empty. access to the SCISR register followed by a read to This bit is set by hardware when the content of the the SCIDR register). TDR register has been transferred into the shift 0: No Overrun error register. An interrupt is generated if the TIE bit = 1 1: Overrun error is detected in the SCICR2 register. It is cleared by a software sequence (an access to the SCISR register folNote: When this bit is set, the RDR register conlowed by a write to the SCIDR register). tent is not lost but the shift register is overwritten. 0: Data is not transferred to the shift register 1: Data is transferred to the shift register Bit 2 = NF Noise flag. Note: Data is not be transferred to the shift register This bit is set by hardware when noise is detected until the TDRE bit is cleared. on a received frame. It is cleared by a software sequence (an access to the SCISR register followed by a read to the SCIDR register). Bit 6 = TC Transmission complete. 0: No noise is detected This bit is set by hardware when transmission of a 1: Noise is detected frame containing Data is complete. An interrupt is generated if TCIE = 1 in the SCICR2 register. It is Note: This bit does not generate interrupt as it apcleared by a software sequence (an access to the pears at the same time as the RDRF bit which itSCISR register followed by a write to the SCIDR self generates an interrupt. register). 0: Transmission is not complete 1: Transmission is complete Bit 1 = FE Framing error. This bit is set by hardware when a de-synchronizaNote: TC is not set after the transmission of a Pretion, excessive noise or a break character is deamble or a Break. tected. It is cleared by a software sequence (an access to the SCISR register followed by a read to Bit 5 = RDRF Received data ready flag. the SCIDR register). This bit is set by hardware when the content of the 0: No Framing error is detected RDR register has been transferred to the SCIDR 1: Framing error or break character is detected register. An interrupt is generated if RIE = 1 in the Note: This bit does not generate an interrupt as it SCICR2 register. It is cleared by a software seappears at the same time as the RDRF bit which itquence (an access to the SCISR register followed self generates an interrupt. If the word currently by a read to the SCIDR register). being transferred causes both frame error and 0: Data is not received overrun error, it is transferred and only the OR bit 1: Received data is ready to be read is set. Bit 4 = IDLE Idle line detect. This bit is set by hardware when an Idle Line is detected. An interrupt is generated if the ILIE = 1 in the SCICR2 register. It is cleared by a software sequence (an access to the SCISR register followed by a read to the SCIDR register). 0: No Idle Line is detected 1: Idle Line is detected Bit 0 = PE Parity error. This bit is set by hardware when a parity error occurs in receiver mode. It is cleared by a software sequence (a read to the status register followed by an access to the SCIDR data register). An interrupt is generated if PIE = 1 in the SCICR1 register. 0: No parity error 1: Parity error
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) CONTROL REGISTER 1 (SCICR1) Read/Write Bit 3 = WAKE Wake-Up method. This bit determines the SCI Wake-Up method, it is Reset Value: x000 0000 (x0h) set or cleared by software. 0: Idle Line 7 0 1: Address Mark
R8 T8 SCID M WAKE PCE PS
PIE
Bit 7 = R8 Receive data bit 8. This bit is used to store the 9th bit of the received word when M = 1. Bit 6 = T8 Transmit data bit 8. This bit is used to store the 9th bit of the transmitted word when M = 1. Bit 5 = SCID Disabled for low power consumption When this bit is set the SCI prescalers and outputs are stopped and the end of the current byte transfer in order to reduce power consumption.This bit is set and cleared by software. 0: SCI enabled 1: SCI prescaler and outputs disabled Bit 4 = M Word length. This bit determines the word length. It is set or cleared by software. 0: 1 Start bit, 8 Data bits, 1 Stop bit 1: 1 Start bit, 9 Data bits, 1 Stop bit Note: The M bit must not be modified during a data transfer (both transmission and reception).
Bit 2 = PCE Parity control enable. This bit selects the hardware parity control (generation and detection). When the parity control is enabled, the computed parity is inserted at the MSB position (9th bit if M = 1; 8th bit if M = 0) and parity is checked on the received data. This bit is set and cleared by software. Once it is set, PCE is active after the current byte (in reception and in transmission). 0: Parity control disabled 1: Parity control enabled Bit 1 = PS Parity selection. This bit selects the odd or even parity when the parity generation/detection is enabled (PCE bit set). It is set and cleared by software. The parity is selected after the current byte. 0: Even parity 1: Odd parity Bit 0 = PIE Parity interrupt enable. This bit enables the interrupt capability of the hardware parity control when a parity error is detected (PE bit set). It is set and cleared by software. 0: Parity error interrupt disabled 1: Parity error interrupt enabled
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) CONTROL REGISTER 2 (SCICR2) Read/Write Bit 2 = RE Receiver enable. This bit enables the receiver. It is set and cleared Reset Value: 0000 0000 (00 h) by software. 0: Receiver is disabled 7 0 1: Receiver is enabled and begins searching for a start bit TIE TCIE RIE ILIE TE RE RWU SBK Bit 7 = TIE Transmitter interrupt enable. This bit is set and cleared by software. 0: Interrupt is inhibited 1: An SCI interrupt is generated whenever TDRE = 1 in the SCISR register Bit 6 = TCIE Transmission complete interrupt enable This bit is set and cleared by software. 0: Interrupt is inhibited 1: An SCI interrupt is generated whenever TC = 1 in the SCISR register Bit 5 = RIE Receiver interrupt enable. This bit is set and cleared by software. 0: Interrupt is inhibited 1: An SCI interrupt is generated whenever OR = 1 or RDRF = 1 in the SCISR register Bit 4 = ILIE Idle line interrupt enable. This bit is set and cleared by software. 0: Interrupt is inhibited 1: An SCI interrupt is generated whenever IDLE = 1 in the SCISR register. Bit 3 = TE Transmitter enable. This bit enables the transmitter. It is set and cleared by software. 0: Transmitter is disabled 1: Transmitter is enabled Notes: During transmission, a "0" pulse on the TE bit ("0" followed by "1") sends a preamble (idle line) after the current word. When TE is set there is a 1 bit-time delay before the transmission starts. Bit 1 = RWU Receiver wake-up. This bit determines if the SCI is in mute mode or not. It is set and cleared by software and can be cleared by hardware when a wake-up sequence is recognized. 0: Receiver in active mode 1: Receiver in mute mode Notes: Before selecting Mute mode (by setting the RWU bit) the SCI must first receive a data byte, otherwise it cannot function in Mute mode with wakeup by Idle line detection. In Address Mark Detection Wake-Up configuration (WAKE bit = 1) the RWU bit cannot be modified by software while the RDRF bit is set. Bit 0 = SBK Send break. This bit set is used to send break characters. It is set and cleared by software. 0: No break character is transmitted 1: Break characters are transmitted Note: If the SBK bit is set to "1" and then to "0", the transmitter sends a BREAK word at the end of the current word.
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) CONTROL REGISTER 3 (SCICR3) 0: Steady low value on SCLK pin outside transmission window. Read/Write 1: Steady high value on SCLK pin outside transReset Value: 0000 0000 (00h) mission window.
7
LINE -
0
CLKEN CPOL CPHA LBCL
Bit 7 = Reserved, must be kept cleared. Bit 6 = LINE LIN Mode Enable. This bit is set and cleared by software. 0: LIN Mode disabled 1: LIN Master mode enabled The LIN Master mode enables the capability to send LIN Synch Breaks (13 low bits) using the SBK bit in the SCICR2 register .In transmission, the LIN Synch Break low phase duration is shown as below:
LINE 0 1 M 0 1 0 1 Number of low bits sent during a LIN Synch Break 10 11 13 14
Bit 1 = CPHA Clock Phase. This bit allows the user to select the phase of the clock output on the SCLK pin. It works in conjunction with the CPOL bit to produce the desired clock/data relationship (see Figure 92 and Figure 93) 0: SCLK clock line activated in middle of data bit. 1: SCLK clock line activated at beginning of data bit. Bit 0 = LBCL Last bit clock pulse. This bit allows the user to select whether the clock pulse associated with the last data bit transmitted (MSB) has to be output on the SCLK pin. 0: The clock pulse of the last data bit is not output to the SCLK pin. 1: The clock pulse of the last data bit is output to the SCLK pin. Note: The last bit is the 8th or 9th data bit transmitted depending on the 8 or 9 bit format selected by the M bit in the SCICR1 register. Table 26. SCI clock on SCLK pin
Bits 5:4 = Reserved, forced by hardware to 0. These bits are not used. Bit 3 = CLKEN Clock Enable. This bit allows the user to enable the SCLK pin. 0: SLK pin disabled 1: SLK pin enabled Bit 2 = CPOL Clock Polarity. This bit allows the user to select the polarity of the clock output on the SCLK pin. It works in conjunction with the CPHA bit to produce the desired clock/data relationship (see Figure 92 and Figure 93).
Data f o r ma t 8 bit 9 bit
M bit 0 1
LBCL bit 0 1 0 1
Number of clock pulses on SCLK 7 8 8 9
Note: These 3 bits (CPOL, CPHA, LBCL) should not be written while the transmitter is enabled.
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) DATA REGISTER (SCIDR) Bits 5:3 = SCT[2:0] SCI Transmitter rate divisor These 3 bits, in conjunction with the SCP1 and Read/Write SCP0 bits define the total division applied to the Reset Value: Undefined bus clock to yield the transmit rate clock in conventional Baud Rate Generator mode. Contains the Received or Transmitted data character, depending on whether it is read from or writTR dividing factor SCT2 SC T1 SCT0 ten to.
1 7
DR7 DR6 DR5 DR4 DR3 DR2 DR1
0
DR0
2 4 8 16 32 64 128
0 0 1 0 1 1
0 1 0 1 0 1 0 1
The Data register performs a double function (read and write) since it is composed of two registers, one for transmission (TDR) and one for reception (RDR). The TDR register provides the parallel interface between the internal bus and the output shift register (see Figure 88 on page 153). The RDR register provides the parallel interface between the input shift register and the internal bus (see Figure 88). BAUD RATE REGISTER (SCIBRR) Read/Write Reset Value: 00 00 0000 (00h)
7
SCP1 SCP0 SCT2 SCT1 SCT0 SCR2
Note: This TR factor is used only when the ETPR fine tuning factor is equal to 00h; otherwise, TR is replaced by the (TR*ETPR) dividing factor. Bits 2:0 = SCR[2:0] SCI Receiver rate divisor. These 3 bits, in conjunction with the SCP1 and SCP0 bits define the total division applied to the bus clock to yield the receive rate clock in conventional Baud Rate Generator mode.
0
SCR1 SCR0
RR dividing factor 1 2 4 8 16 32 64 128
SCR2
SC R1 0
S CR0 0 1 0 1 0 1 0 1
0 1 0 1 1
Bits 7:6 = SCP[1:0] First SCI Prescaler These 2 prescaling bits allow several standard clock division ranges:
PR Prescaling factor 1 3 4 13 SCP1 0 1 SCP 0 0 1 0 1
Note: This RR factor is used only when the ERPR fine tuning factor is equal to 00h; otherwise, RR is replaced by the (RR*ERPR) dividing factor.
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LINSCITM SERIAL COMMUNICATION INTERFACE (LIN Master Only) (Cont'd) EXTENDED RECEIVE PRESCALER DIVISION EXTENDED TRANSMIT PRESCALER DIVISION REGISTER (SCIERPR) REGISTER (SCIETPR) Read/Write Read/Write Reset Value: 0000 0000 (00 h) Reset Value:0000 0000 (00 h)
7 0 7
ETPR 7 ETPR 6 ETPR 5 ETPR 4 ETPR 3 ETPR 2
0
ETPR ETPR 1 0
ERPR ERPR ERPR ERPR ERPR ERPR ERPR ERPR 7 6 5 4 3 2 1 0
Bits 7:0 = ERPR[7:0] 8-bit Extended Receive Prescaler Register. The extended Baud Rate Generator is activated when a value other than 00h is stored in this register. The clock frequency from the 16 divider (see Figure 90) is divided by the binary factor set in the SCIERPR register (in the range 1 to 255). The extended baud rate generator is not active after a reset. Table 27. Baud Rate Selection
Bits 7:0 = ETPR[7:0] 8-bit Extended Transmit Prescaler Register. The extended Baud Rate Generator is activated when a value other than 00h is stored in this register. The clock frequency from the 16 divider (see Figure 90) is divided by the binary factor set in the SCIETPR register (in the range 1 to 255). The extended baud rate generator is not active after a reset.
Conditions Symbol Parameter f CPU Accuracy vs. Standard Prescaler Conventional Mode TR (or RR) = 128, PR = 13 TR (or RR) = 32, PR = 13 TR (or RR) = 16, PR =13 TR (or RR) = 8, PR = 13 TR (or RR) = 4, PR = 13 TR (or RR) = 16, PR = 3 TR (or RR) = 2, PR = 13 TR (or RR) = 1, PR =13 Extended Mode ETPR (or ERPR) = 35, TR (or RR) = 1, PR = 1 Standard
Baud Rate
Unit
~0.16% f Tx f Rx C o m mu n i c a t i o n frequency 8 MHz
300 ~300.48 1200 ~1201.92 2400 ~2403.84 4800 ~4807.69 9600 ~9615.38 10400 ~10416.67 19200 ~19230.77 38400 ~38461.54 14400 ~14285.71
Hz
~0.79%
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Table 28. LINSCI2 Register Map and Reset Values
Address (Hex.) 60 61 62 63 64 65 66 67 Register Name SCI2S R Reset Value SCI2D R Reset Value SCI2B R R Reset Value SCI2C R 1 Reset Value SCI2C R 2 Reset Value SCI2C R 3 Reset Value SCI2E R PR Reset Value SCI2E T PR Reset Value 7 TDRE 1 DR7 SCP1 0 R8 TIE 0 0 ERPR7 0 ETPR7 0 6 TC 1 D R6 SCP0 0 T8 TCIE 0 LINE 0 ER PR6 0 E T PR6 0 5 RD RF 0 DR5 S CT 2 0 SCID RIE 0 0 ERPR5 0 ETPR5 0 4 IDLE 0 DR4 SC T1 0 M ILI E 0 0 ERPR4 0 ETPR4 0 3 OR 0 DR 3 SCT0 0 W AKE TE 0 CLKEN 0 ERP R3 0 ETPR 3 0 2 NF 0 DR2 SCR2 0 PCE RE 0 CPO L 0 ERPR2 0 ETPR2 0 1 FE 0 DR1 S CR1 0 PS RWU 0 C PHA 0 ERPR1 0 ETPR1 0 0 PE 0 D R0 SCR0 0 PIE S BK 0 LBCL 0 ER PR0 0 E T PR0 0
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10.9 beCAN CONTROLLER (beCAN) The beCAN controller (Basic Enhanced CAN), interfaces the CAN network and supports the CAN protocol version 2.0A and B. It has been designed to manage high number of incoming messages efficiently with a minimum CPU load. It also meets the priority requirements for transmit messages. 10.9.1 Main Features Supports CAN protocol version 2.0 A, B Active Bit rates up to 1Mbit/s Transmission 2 transmit mailboxes Configurable transmit priority Reception 1 receive FIFO with three stages 6 scalable filter banks Identifier list feature Configurable FIFO overrun Management Maskable interrupts Software-efficient mailbox mapping at a unique address space Figure 94. CAN Network Topology 10.9.2 General Description In today's CAN applications, the number of nodes in a network is increasing and often several networks are linked together via gateways. Typically the number of messages in the system (and thus to be handled by each node) has significantly increased. In addition to the application messages, Network Management and Diagnostic messages have been introduced. An enhanced filtering mechanism is required to handle each type of message. Furthermore, application tasks require more CPU time, therefore real-time constraints caused by message reception have to be reduced. A receive FIFO scheme allows the CPU to be dedicated to application tasks for a long time period without losing messages. The standard HLP (Higher Layer Protocol) based on standard CAN drivers requires an efficient interface to the CAN controller. All mailboxes and registers are organized in 16byte pages mapped at the same address and selected via a page select register.
CAN node 1
CAN node 2
ST9 MCU Application
CAN Controller CAN Rx CAN Transceiver CAN High CAN Low CAN Tx
CAN Bus
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beCAN CONTROLLER (Cont'd) CAN 2.0B Active Core The beCAN module handles the transmission and the reception of CAN messages fully autonomously. Standard identifiers (11-bit) and extended identifiers (29-bit) are fully supported by hardware. Control, Status and Configuration Registers The application uses these registers to: Configure CAN parameters, e.g.baud rate Request transmissions Handle receptions Manage interrupts Get diagnostic information
Tx Mailboxes Two transmit mailboxes are provided to the software for setting up messages. The Transmission Scheduler decides which mailbox has to be transmitted first. Acceptance Filters The beCAN provides six scalable/configurable identifier filter banks for selecting the incoming messages the software needs and discarding the others. Receive FIFO The receive FIFO is used by the CAN controller to store the incoming messages. Three complete messages can be stored in the FIFO. The software always accesses the next available message at the same address. The FIFO is managed completely by hardware.
Figure 95. CAN Block Diagram
Tx Mailboxes Master Control Master Status Transmit Status Transmit Prio Control/Status/Configuration Receive FIFO Interrupt Enable Page Select Error Status Error Int. Enable Tx Error Counter Rx Error Counter Diagnostic Bit Timing Filter Master Filter Config. Transmission Scheduler Filter Mailbox 0 Mailbox 1
Receive FIFO 2 Mailbox 0 1
Acceptance Filters 34 21 01 5
CAN 2.0B Active Core
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beCAN CONTROLLER (Cont'd) Figure 96. beCAN Operating Modes
RESET
SLEE P
SLAK= 1 INAK = 0
SLE EP
SL EE P
S YNC
SLAK= X INAK = X
SL EEP
NORM AL
SLAK= 0 INAK = 0
SL
EE
P*
Q IN R
INR Q
INR
Q
IN ITIALIZATION
SLAK= 0 INAK = 1
INRQ
10.9.3 Operating Modes The beCAN has three main operating modes: Initialization, Normal and Sleep. After a hardware reset, beCAN is in Sleep mode to reduce power consumption. The software requests beCAN to enter Initialization or Sleep mode by setting the INRQ or SLEEP bits in the CMCR register. Once the mode has been entered, beCAN confirms it by setting the INAK or SLAK bits in the CMSR register. When neither INAK nor SLAK are set, beCAN is in Normal mode. Before entering Normal mode beCAN always has to synchronize on the CAN bus. To synchronize, beCAN waits until the CAN bus is idle, this means 11 consecutive recessive bits have been monitored on CANRX. 10.9.3.1 Initialization Mode The software initialization can be done while the hardware is in Initialization mode. To enter this mode the software sets the INRQ bit in the CMCR register and waits until the hardware has confirmed the request by setting the INAK bit in the CMSR register. To leave Initialization mode, the software clears the INQR bit. beCAN has left Initialization mode once the INAK bit has been cleared by hardware. While in Initialization mode, all message transfers to and from the CAN bus are stopped and the sta-
tus of the CAN bus output CANTX is recessive (high). Entering Initialization Mode does not change any of the configuration registers. To initialize the CAN Controller, software has to set up the Bit Timing registers and the filter banks. If a filter bank is not used, it is recommended to leave it non active (leave the corresponding FACT bit cleared). 10.9.3.2 Normal Mode Once the initialization has been done, the software must request the hardware to enter Normal mode, to synchronize on the CAN bus and start reception and transmission. Entering Normal mode is done by clearing the INRQ bit in the CMCR register and waiting until the hardware has confirmed the request by clearing the INAK bit in the CMSR register. Afterwards, the beCAN synchronizes with the data transfer on the CAN bus by waiting for the occurrence of a sequence of 11 consecutive recessive bits ( Bus Idle) before it can take part in bus activities and start message transfer. The initialization of the filter values is independent from Initialization mode but must be done while the filter bank is not active (corresponding FACTx bit cleared). The filter bank scale and mode configuration must be configured in initialization mode.
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beCAN CONTROLLER (Cont'd) 10.9.3.3 Low Power Mode (Sleep) To reduce power consumption, beCAN has a low power mode called Sleep mode. This mode is entered on software request by setting the SLEEP bit in the CMCR register. In this mode, the beCAN clock is stopped. Consequently, software can still access the beCAN registers and mailboxes but the beCAN will not update the status bits. Example: If software requests entry to initialization mode by setting the INRQ bit while beCAN is in sleep mode, it will not be acknowledged by the hardware, INAK stays cleared. beCAN can be woken up (exit Sleep mode) either by software clearing the SLEEP bit or on detection of CAN bus activity. On CAN bus activity detection, hardware automatically performs the wake-up sequence by clearing the SLEEP bit if the AWUM bit in the CMCR register is set. If the AWUM bit is cleared, software has to clear the SLEEP bit when a wake-up interrupt occurs, in order to exit from sleep mode. Note: If the wake-up interrupt is enabled (WKUIE bit set in CIER register) a wake-up interrupt will be generated on detection of CAN bus activity, even if the beCAN automatically performs the wake-up sequence. After the SLEEP bit has been cleared, Sleep mode is exited once beCAN has synchronized with the CAN bus, refer to Figure 3. beCAN Operating Modes. The sleep mode is exited once the SLAK bit has been cleared by hardware. 10.9.3.4 Test Mode Test mode can be selected by the SILM and LBKM bits in the CDGR register. These bits must be configured while beCAN is in Initialization mode. Once test mode has been selected, beCAN is started in Normal mode. 10.9.3.5 Silent Mode The beCAN can be put in Silent mode by setting the SILM bit in the CDGR register. In Silent mode, the beCAN is able to receive valid data frames and valid remote frames, but it sends only recessive bits on the CAN bus and it cannot start a transmission. If the beCAN has to send a dominant bit (ACK bit, overload flag, active error flag), the bit is rerouted internally so that the CAN Core monitors this dominant bit, although the CAN bus may remain in recessive state. Silent mode can be used to analyze the traffic on a CAN bus
without affecting it by the transmission of dominant bits (Acknowledge Bits, Error Frames). Figure 97. beCAN in Silent Mode beCAN Tx Rx
=1
C A N T X CA N R X 10.9.3.6 Loop Back Mode The beCAN can be set in Loop Back Mode by setting the LBKM bit in the CDGR register. In Loop Back Mode, the beCAN treats its own transmitted messages as received messages and stores them (if they pass acceptance filtering) in the FIFO. Figure 98. beCAN in Loop Back Mode beCAN Tx Rx
CA NTX CAN RX This mode is provided for self-test functions. To be independent of external events, the CAN Core ignores acknowledge errors (no dominant bit sampled in the acknowledge slot of a data / remote frame) in Loop Back Mode. In this mode, the beCAN performs an internal feedback from its Tx output to its Rx input. The actual value of the CANRX input pin is disregarded by the beCAN. The transmitted messages can be monitored on the CANTX pin.
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beCAN CONTROLLER (Cont'd) 10.9.3.7 Loop Back combined with Silent Mode It is also possible to combine Loop Back mode and Silent mode by setting the LBKM and SILM bits in the CDGR register. This mode can be used for a "Hot Selftest", meaning the beCAN can be tested like in Loop Back mode but without affecting a running CAN system connected to the CANTX and CANRX pins. In this mode, the CANRX pin is disconnected from the beCAN and the CANTX pin is held recessive. Figure 99. beCAN in Combined Mode beCAN Tx Rx
=1
CANTX CANRX 10.9.4 Functional Description 10.9.4.1 Transmission Handling In order to transmit a message, the application must select one empty transmit mailbox, set up the identifier, the data length code (DLC) and the data before requesting the transmission by setting the corresponding TXRQ bit in the MCSR register. Once the mailbox has left empty state, the software no longer has write access to the mailbox registers. Immediately after the TXRQ bit has been set, the mailbox enters pending state and waits to become the highest priority mailbox, see Transmit Priority. As soon as the mailbox has the highest priority it will be scheduled for transmission. The transmission of the message of the scheduled mailbox will start (enter transmit state) when the CAN bus becomes idle. Once the mailbox has been successfully transmitted, it will become empty again. The hardware indicates a successful transmission by setting the RQCP and TXOK bits in the MCSR and CTSR registers. If the transmission fails, the cause is indicated by the ALST bit in the MCSR register in case of an Ar-
bitration Lost, and/or the TERR bit, in case of transmission error detection. Transmit Priority By Identifier: When more than one transmit mailbox is pending, the transmission order is given by the identifier of the message stored in the mailbox. The message with the lowest identifier value has the highest priority according to the arbitration of the CAN protocol. If the identifier values are equal, the lower mailbox number will be scheduled first. By Transmit Request Order: The transmit mailboxes can be configured as a transmit FIFO by setting the TXFP bit in the CMCR register. In this mode the priority order is given by the transmit request order. This mode is very useful for segmented transmission. Abort A transmission request can be aborted by the user setting the ABRQ bit in the MCSR register. In pending or scheduled state, the mailbox is aborted immediately. An abort request while the mailbox is in transmit state can have two results. If the mailbox is transmitted successfully the mailbox becomes empty with the TXOK bit set in the MCSR and CTSR registers. If the transmission fails, the mailbox becomes scheduled, the transmission is aborted and becomes empty with TXOK cleared. In all cases the mailbox will become empty again at least at the end of the current transmission. Non-Automatic Retransmission Mode To configure the hardware in this mode the NART bit in the CMCR register must be set. In this mode, each transmission is started only once. If the first attempt fails, due to an arbitration loss or an error, the hardware will not automatically restart the message transmission. At the end of the first transmission attempt, the hardware considers the request as completed and sets the RQCP bit in the MCSR register. The result of the transmission is indicated in the MCSR register by the TXOK, ALST and TERR bits.
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beCAN CONTROLLER (Cont'd) Figure 100. Transmit Mailbox States
E MP T Y
RQCP=X TXOK=X TME = 1
T X R Q= 1
P E NDIN G ABRQ =1
RQCP=0 TXOK=0 TME = 0
Mailbox has highest priority
EMP T Y
Mailbox does not have highest priority
ABRQ =1
SCH EDULED
RQCP=0 TXOK=0 TME = 0
RQCP=1 TXOK=0 TME = 1
CAN Bus = IDLE
TRANSMIT
RQCP=0 TXOK=0 TME = 0
Transmit failed * NART
Transmit failed * NART
EMPTY
RQCP=1 TXOK=1 TME = 1
Transmit succeeded
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beCAN CONTROLLER (Cont'd) 10.9.4.2 Reception Handling For the reception of CAN messages, three mailboxes organized as a FIFO are provided. In order to save CPU load, simplify the software and guarantee data consistency, the FIFO is managed completely by hardware. The application accesses the messages stored in the FIFO through the FIFO output mailbox. Valid Message Figure 101. Receive FIFO states
E MP T Y
FMP=0x00 FOVR=0
A received message is considered as valid when it has been received correctly according to the CAN protocol (no error until the last but one bit of the EOF field) and It passed through the identifier filtering successfully, see Section 0.1.4.3 Identifier Filtering.
Valid Message
Received
Release Mailbox
PENDING_1
FMP=0x01 FOVR=0
Release Mailbox RFOM=1
FMP=0x10 FOVR=0
Valid Message
Received
PENDING_2
Release Mailbox RFOM=1
FMP=0x11 FOVR=0
Valid Message
Received
PENDING_3
Valid Message
Received
Release Mailbox RFOM=1
OVE RRUN
FMP=0x11 FOVR=1
Valid Message
Received
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beCAN CONTROLLER (Cont'd) FIFO Management Starting from the empty state, the first valid message received is stored in the FIFO which becomes pending_1. The hardware signals the event setting the FMP[1:0] bits in the CRFR register to the value 01b. The message is available in the FIFO output mailbox. The software reads out the mailbox content and releases it by setting the RFOM bit in the CRFR register. The FIFO becomes empty again. If a new valid message has been received in the meantime, the FIFO stays in pending_1 state and the new message is available in the output mailbox. If the application does not release the mailbox, the next valid message will be stored in the FIFO which enters pending_2 state (FMP[1:0] = 10b). The storage process is repeated for the next valid message putting the FIFO into pending_3 state (FMP[1:0] = 11b). At this point, the software must release the output mailbox by setting the RFOM bit, so that a mailbox is free to store the next valid message. Otherwise the next valid message received will cause a loss of message. Refer also to Section 0.1.4.4 Message Storage. Overrun Once the FIFO is in pending_3 state (that is, the three mailboxes are full) the next valid message reception will lead to an overrun and a message will be lost. The hardware signals the overrun condition by setting the FOVR bit in the CRFR register. Which message is lost depends on the configuration of the FIFO: If the FIFO lock function is disabled (RFLM bit in the CMCR register cleared) the last message stored in the FIFO will be overwritten by the new incoming message. In this case the latest messages will be always available to the application. If the FIFO lock function is enabled (RFLM bit in the CMCR register set) the most recent message will be discarded and the software will have the three oldest messages in the FIFO available. Reception Related Interrupts On the storage of the first message in the FIFO FMP[1:0] bits change from 00b to 01b - an interrupt is generated if the FMPIE bit in the CIER register is set. When the FIFO becomes full (that is, a third message is stored) the FULL bit in the CRFR register is set and an interrupt is generated if the FFIE bit in the CIER register is set.
On overrun condition, the FOVR bit is set and an interrupt is generated if the FOVIE bit in the CIER register is set. 10.9.4.3 Identifier Filtering In the CAN protocol the identifier of a message is not associated with the address of a node but related to the content of the message. Consequently a transmitter broadcasts its message to all receivers. On message reception a receiver node decides - depending on the identifier value - whether the software needs the message or not. If the message is needed, it is copied into the RAM. If not, the message must be discarded without intervention by the software. To fulfil this requirement, the beCAN Controller provides six configurable and scalable filter banks (0-5) in order to receive only the messages the software needs. This hardware filtering saves CPU resources which would be otherwise needed to perform filtering by software. Each filter bank consists of eight 8-bit registers, CFxR[0:7]. Scalable Width To optimize and adapt the filters to the application needs, each filter bank can be scaled independently. Depending on the filter scale a filter bank provides: One 32-bit filter for the STDID[10:0], IDE, EXTID[17:0] and RTR bits. Two 16-bit filters for the STDID[10:0], RTR and IDE bits. Four 8-bit filters for the STDID[10:3] bits. The other bits are considered as "don't care". One 16-bit filter and two 8-bit filters for filtering the same set of bits as the 16 and 8-bit filters described above. Refer to Figure 9. Filter Bank Scale Configuration Register Organisation. Furthermore, the filters can be configured in mask mode or in identifier list mode. Mask mode In mask mode the identifier registers are associated with mask registers specifying which bits of the identifier are handled as "must match" or as "don't care". Identifier List mode In identifier list mode, the mask registers are used as identifier registers. Thus instead of defining an identifier and a mask, two identifiers are specified, doubling the number of single identifiers. All bits of the incoming identifier must match the bits specified in the filter registers.
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beCAN CONTROLLER (Cont'd) Figure 102. Filter Bank Scale Configuration - Register Organisation Filter Bank Scale Configuration One 32-Bit Filter Identifier Mask/Ident. Bit Mapping CFxR0 CFxR4
STID10:3
Filter Bank Scale Config. Bits1 FSCx = 3
CFxR 1 CFxR 5
STID2:0 RTR IDE EXID17:15
C F xR2 C F xR6
EXID14:7
CFxR 3 CFxR 7
EXID6:0
Two 16-Bit Filters Identifier Mask/Ident. Identifier Mask/Ident. Bit Mapping CFxR0 CFxR2 CFxR4 CFxR6
STID10:3
CFxR 1 CFxR 3 FSCx = 2 CFxR 5 CFxR 7
STID2:0 RTR IDE EXID17:15
One 16-Bit / Two 8-Bit Filters Identifier Mask/Ident. Identifier Mask/Ident. Identifier Mask/Ident. C F x R0 C F x R2 C F x R4 C F x R5 FSCx = 1 CFxR6 CFxR7 Four 8-Bit Filters Identifier Mask/Ident. Identifier Mask/Ident. Identifier Mask/Ident. Identifier Mask/Ident. Bit Mapping CFxR0 CFxR1 CFxR2 CFxR3 CFxR4 CFxR5 CFxR6 CFxR7
STID10:3
CFxR1 CFxR3
FSCx = 0
x = filter bank number
1
These bits are located in the CFCR register
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beCAN CONTROLLER (Cont'd) Filter Bank Scale and Mode Configuration The filter banks are configured by means of the corresponding CFCRx register. To configure a filter bank this must be deactivated by clearing the FACT bit in the CFCR register. The filter scale is configured by means of the FSC[1:0] bits in the corresponding CFCR register, refer to Figure 9. Filter Bank Scale Configuration - Register Organisation. The identifier list or identifier mask mode for the corresponding Mask/Identifier registers is configured by means of the FMCLx and FMCHx bits in the CFMR register. The FMCLx bit defines the mode for the two least significant bytes, and the FMCHx bit the mode for the two most significant bytes of filter bank x. Examples: If filter bank 1 is configured as two 16-bit filters, then the FMCL1 bit defines the mode of the CF1R2 and CF1R3 registers and the FMCH1 bit defines the mode of the CF1R6 and CF1R7 regis ters. If filter bank 2 is configured as four 8-bit filters, then the FMCL2 bit defines the mode of the CF2R1 and CF2R3 registers and the FMCH2 bit defines the mode of the CF2R5 and CF2R7 regis ters. Note: In 32-bit configuration, the FMCLx and FMCHx bits must have the same value to ensure that the four Mask/Identifier registers are in the same mode. To filter a group of identifiers, configure the Mask/ Identifier registers in mask mode. To select single identifiers, configure the Mask/ Identifier registers in identifier list mode. Filters not used by the application should be left deactivated. Filter Match Index Once a message has been received in the FIFO it is available to the application. Typically application
data are copied into RAM locations. To copy the data to the right location the application has to identify the data by means of the identifier. To avoid this and to ease the access to the RAM locations, the CAN controller provides a Filter Match Index. This index is stored in the mailbox together with the message according to the filter priority rules. Thus each received message has its associated Filter Match Index. The Filter Match Index can be used in two ways: Compare the Filter Match Index with a list of expected values. Use the Filter Match Index as an index on an array to access the data destination location. For non-masked filters, the software no longer has to compare the identifier. If the filter is masked the software reduces the comparison to the masked bits only. Filter Priority Rules Depending on the filter combination it may occur that an identifier passes successfully through several filters. In this case the filter match value stored in the receive mailbox is chosen according to the following rules: A filter in identifier list mode prevails on an filter in mask mode. A filter with full identifier coverage prevails over filters covering part of the identifier, e.g. 16-bit filters prevail over 8-bit filters. Filters configured in the same mode and with identical coverage are prioritized by filter number and register number. The lower the number the higher the priority.
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beCAN CONTROLLER (Cont'd) Figure 103. Filtering Mechanism - example Message Received Identifier Ctrl Data
Receive FIFO Identifier List Identifier Identifier Identifier 0 1 2 Identifier #2 Match Mess age Stored
Identifier
n
Identifier & Mask
Identifier Mask
n+1
n+m Identifier Mask No Match Found Message Discarded
n: number of single identifiers to receive m: number of identifier groups to receive n and m values depend on the configuration of the filters If there is no match, the incoming identifier is then compared with the filters configured in mask mode. If the identifier does not match any of the identifiers configured in the filters, the message is discarded by hardware without software intervention.
The example above shows the filtering principle of the beCAN. On reception of a message, the identifier is compared first with the filters configured in identifier list mode. If there is a match, the message is stored in the FIFO and the index of the matching filter is stored in the Filter Match Index. As shown in the example, the identifier matches with Identifier #2 thus the message content and MFMI 2 is stored in the FIFO.
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beCAN CONTROLLER (Cont'd) 10.9.4.4 Message Storage The interface between the software and the hardware for the CAN messages is implemented by means of mailboxes. A mailbox contains all information related to a message; identifier, data, control and status information. Transmit Mailbox The software sets up the message to be transmitted in an empty transmit mailbox. The status of the transmission is indicated by hardware in the MCSR register. Transmit Mailbox Mapping
Offset to Transmit Mailbox base address (bytes) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Register Name MCSR MDLC MIDR0 MIDR1 MIDR2 MIDR3 MDAR 0 MDAR 1 MDAR 2 MDAR 3 MDAR 4 MDAR 5 MDAR 6 MDAR 7 Reserved Reserved
Receive Mailbox When a message has been received, it is available to the software in the FIFO output mailbox. Once the software has handled the message (e.g. read it) the software must release the FIFO output mailbox by means of the RFOM bit in the CRFR register to make the next incoming message available. The filter match index is stored in the MFMI register.
Receive Mailbox Mapping Offset to Receive Mailbox base address (bytes) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Register Name MFM I MDLC MIDR0 MIDR1 MIDR2 MIDR3 MDA R0 MDA R1 MDA R2 MDA R3 MDA R4 MDA R5 MDA R6 MDA R7 Reserved Reserved
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beCAN CONTROLLER (Cont'd) Figure 104. CAN Error State Diagram
When TEC or REC > 127
ERROR ACTIVE
ERROR PASSIVE
When TEC and REC < 128,
When 128 * 11 recessive bits occur:
When TEC > 255
BUS OFF
10.9.4.5 Error Management The error management as described in the CAN protocol is handled entirely by hardware using a Transmit Error Counter (TECR register) and a Receive Error Counter (RECR register), which get incremented or decremented according to the error condition. For detailed information about TEC and REC management, please refer to the CAN standard. Both of them may be read by software to determine the stability of the network. Furthermore, the CAN hardware provides detailed information on the current error status in CESR register. By means of CEIER register and ERRIE bit in CIER register, the software can configure the interrupt generation on error detection in a very flexible way.
Bus-Off Recovery The Bus-Off state is reached when TECR is greater then 255, this state is indicated by BOFF bit in CESR register. In Bus-Off state, the beCAN acts as disconnected from the CAN bus, hence it is no longer able to transmit and receive messages. Depending on the ABOM bit in the CMCR register beCAN will recover from Bus-Off (become error active again) either automatically or on software request. But in both cases the beCAN has to wait at least for the recovery sequence specified in the CAN standard (128 x 11 consecutive recessive bits monitored on CANRX). If ABOM is set, the beCAN will start the recovering sequence automatically after it has entered BusOff state. If ABOM is cleared, the software must initiate the recovering sequence by requesting beCAN to enter initialization mode. Then beCAN starts monitoring the recovery sequence when the beCAN is requested to leave the initialisation mode. Note: In initialization mode, beCAN does not monitor the CANRX signal, therefore it cannot complete the recovery sequence. To recover, beCAN must be in normal mode.
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beCAN CONTROLLER (Cont'd) 10.9.4.6 Bit Timing The bit timing logic monitors the serial bus-line and performs sampling and adjustment of the sample point by synchronizing on the start-bit edge and resynchronizing on the following edges. Its operation may be explained simply by splitting nominal bit time into three segments as follows: Synchronization segment (SYNC_SEG): a bit change is expected to occur within this time segment. It has a fixed length of one time quantum (1 x tCAN). Bit segment 1 (BS1): defines the location of the sample point. It includes the PROP_SEG and PHASE_SEG1 of the CAN standard. Its duration is programmable between 1 and 16 time quanta but may be automatically lengthened to compensate for positive phase drifts due to differences in the frequency of the various nodes of the network. Bit segment 2 (BS2): defines the location of the transmit point. It represents the PHASE_SEG2 of the CAN standard. Its duration is programmable between 1 and 8 time quanta but may also be automatically shortened to compensate for negative phase drifts. Resynchronization Jump Width (RJW): defines an upper bound to the amount of lengthening or shortening of the bit segments. It is programmable between 1 and 4 time quanta. To guarantee the correct behaviour of the CAN controller, SYNC_SEG + BS1 + BS2 must be greater than or equal to 5 time quanta. For a detailed description of the CAN resynchronization mechanism and other bit timing configuration constraints, please refer to the Bosch CAN standard 2.0. As a safeguard against programming errors, the configuration of the Bit Timing Registers CBTR1 and CBTR0 is only possible while the device is in Initialization mode.
Figure 105. Bit Timing
NOMINAL BIT TIME SYNC_SEG BIT SEGMENT 1 (BS1) BIT SEGMENT 2 (BS2)
1 x t CAN
tBS1
tBS2
SAMPLE POINT
TRANSMIT POINT
Figure 106. CAN Frames (Part 1of 2)
Inter-Frame Space Data Frame (Standard identifier) 44 + 8 * N Arbitration Field Control Field Data Field 12 ID RTR IDE r0 S OF 6 DLC 8*N CRC Field 16 CRC ACK Ack Field 2 Inter-Frame Space or Overload Frame
7 EOF
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beCAN CONTROLLER (Cont'd) Figure 107. CAN Frames (Part 2 of 2)
Inter-Frame Space Data Frame (Extended Identifier) 64 + 8 * N Std Arbitr. Field 12 ID SRR IDE RTR r1 r0 SOF Ext Arbitr. Field 20 Ctrl Field 6 DLC Data Field 8*N CRC Field Ack Field 2 16 7 CR C ACK Inter-Frame Space or Overload Frame 16 CRC ACK Ack Field 2 End Of Frame 7 Notes: Any Frame Inter-Frame Space Bus Idle Data Frame or Remote Frame · 0 <= N <= 8 · SOF = Start Of Frame · ID = Identifier · RTR = Remote Transmission Request · IDE = Identifier Extension Bit · r0 = Reserved Bit · DLC = Data Length Code End Of Frame or Error Delimiter or Overload Delimiter · CRC = Cyclic Redundancy Code Overload Frame Inter-Frame Space or Error Frame · Error flag: 6 dominant bits if node is error active else 6 recessive bits. Overload Flag Overload Delimiter 6 8 · Suspend transmission: applies to error passive nodes only. · EOF = End of Frame · ACK = Acknowledge bit EOF Inter-Frame Space or Overload Frame
Inter-Frame Space
Remote Frame 44
Arbitration Field Control Field 12 ID SOF RTR IDE r0 6 DLC
CRC Field
Data Frame or Remote Frame
Error Frame
Inter-Frame Space or Overload Frame
Error Flag Flag Echo Error Delimiter 6 6 8
Suspend Intermission Transmission 3 8
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beCAN CONTROLLER (Cont'd) 10.9.5 Interrupts Two interrupt vectors are dedicated to beCAN. Each interrupt source can be independently enaFigure 108. Event flags and Interrupt Generation bled or disabled by means of the CAN Interrupt Enable Register (CIER) and CAN Error Interrupt Enable register (CEIER).
FMPIE FMP CRFR FFIE FULL FOVIE FOVR
& & & +
FI FO INTERRUPT
EWGIE EWGF EPVIE CESR EPVF BOFIE BOFF LECIE LECIEF
& & & &
CIER ERRIE
+
&
TRANSMIT/ ERROR/ STATUS CHANGE INTERRUPT
+ & &
MCSR
TXMB 0 TXMB 1
RQCP RQCP
TMEIE
+
WKUIE
CMSR
WKUI
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beCAN CONTROLLER (Cont'd) The FIFO interrupt can be generated by the following events: Reception of a new message, FMP bits in the CRFR0 register incremented. FIFO0 full condition, FULL bit in the CRFR0 register set. FIFO0 overrun condition, FOVR bit in the CRFR0 register set. The transmit, error and status change interrupt can be generated by the following events: Transmit mailbox 0 becomes empty, RQCP0 bit in the CTSR register set. Transmit mailbox 1 becomes empty, RQCP1 bit in the CTSR register set. Error condition, for more details on error conditions please refer to the CAN Error Status register (CESR). Wake-up condition, SOF monitored on the
CAN Rx signal. 10.9.6 Register Access Protection Erroneous access to certain configuration registers can cause the hardware to temporarily disturb the whole CAN network. Therefore the following registers can be modified by software only while the hardware is in initialization mode: CBTR0, CBTR1, CFCR0, CFCR1, CFMR and CDGR registers. Although the transmission of incorrect data will not cause problems at the CAN network level, it can severely disturb the application. A transmit mailbox can be only modified by software while it is in empty state (refer to Figure 7. Transmit Mailbox States). The filters must be deactivated before their value can be modified by software. The modification of the filter configuration (scale or mode) can be done by software only in initialization mode.
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beCAN CONTROLLER (Cont'd) 10.9.7 BeCAN Cell Limitations 10.9.7.1 FIFO Corruption FIFO corruption occurs in the following case: WHEN the beCAN RX FIFO already holds two messages (that is, FMP == 2) AND the application releases the FIFO (with the instruction CRFR = B_RFOM;) WHILE the beCAN requests the transfer of a new receive message into the FIFO (this lasts one CPU cycle) THEN the internal FIFO pointer is not updated BUT the FMP bits are updated correctly Figure 109. FIFO Corruption FMP Initial State Receive Message A Receive Message B Receive Message C Release Message A 0 1 2 3 2 FIFO * v --v A v A v A * -* B-
As the FIFO pointer is not updated correctly, this causes the last message received to be overwritten by any incoming message. This means one message is lost as shown in the example in Figure 16. The beCAN will not recover normal operation until a device reset occurs.
When the FIFO is empty, v and * point to the same location
Release Message B 2 and Receive Message D Receive Message E Release Message C Release Message E Release Message B 3 2 1 0
* B C * does not move because FIFO is full (normal operation) *v ABC *v Normal operation DBC v * D B C * Does not move, pointer corruption *v E B C D is overwritten by E v* E B C C released v * E B C E released instead of B *v E B C * and v are not pointing to the same message the FIFO is empty
* pointer to next receive location v pointer to next message to be released
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beCAN CONTROLLER (Cont'd) Workaround To implement the workaround, use the following sequence to release the CAN receive FIFO. This sequence replaces any occurrence of CRFR |= B_RFOM;. Figure 110. Workaround 1
if ((CRFR & 0x03) == 0x02) while (( CMSR & 0x20) && ( CDGR & 0x08) ) CRFR |= B_RFOM; { };
Explanation of Workaround 1 First, we need to make sure no interrupt can occur between the test and the release of the FIFO to avoid any added delay. The workaround checks if the first two FIFO levels are already full (FMP = 2) as the problem happens only in this case. If FMP 2 we release the FIFO immediately, if FMP = 2, we monitor the reception status of the cell. The reception status is available in the CMSR register bit 5 (REC bit). Note: The REC bit was called RX in older versions of the datasheet. If the cell is not receiving, then REC bit in CMSR is at 0, the software can release the FIFO immediately: there is no risk. If the cell is receiving, it is important to make sure the release of the mailbox will not happen at the time when the received message is loaded into the FIFO. We could simply wait for the end of the reception, but this could take a long time (200s for a 100-bit
if ((CRFR & 0x03) == 0x02) ld and cp jrne
frame at 500 kHz), so we also monitor the Rx pin of the microcontroller to minimize the time the application may wait in the while loop. We know the critical window is located at the end of the frame, 6+ CAN bit times after the acknowledge bit (exactly six full bit times plus the time from the beginning of the bit to the sample point). Those bits represent the acknowledge delimiter + the end of frame slot. We know also that those 6+ bits are in recessive state on the bus, therefore if the CAN Rx pin of the device is at `0', (reflecting a CAN dominant state on the bus), this is early enough to be sure we can release the FIFO before the critical time slot. Therefore, if the device hardware pin Rx is at 0 and there is a reception on going, its message will be transferred to the FIFO only 6+ CAN bit times later at the earliest (if the dominant bit is the acknowledge) or later if the dominant bit is part of the message. Compiled with Cosmic C compiler, the workaround generates the following assembly lines:
Cycles
a, CRFR a,#3 a,#2 _RELEASE
3 2 2 3
test: 10 cycles
while (( CMSR & 0x20) && ( CDGR & 0x08) ) { }; _WHILELOOP: btjf CMSR,#5,_RELEASE 5 btjt CDGR,#3,_WHILELOOP 5 loop: 10 cycles CRFR |= B_RFOM; _RELEASE: bset CRFR,#5 5 release: 5 cycles
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beCAN CONTROLLER (Cont'd) In the worst case configuration, if the CAN cell speed is set to the maximum baud rate, one bit time is 8 CPU cycle. In this case the minimum time between the end of the acknowledge and the critical period is 52 CPU cycles (48 for the 6 bit times + 4 for the (PROP SEG + TSeg 1). According to the previous code timing, we need less than 15 cycles from the time we see the dominant state to the time we perform the FIFO release (one full loop + the actual release) therefore the application will never release the FIFO at the critical time when this workaround is implemented. Timing analysis - Time spent in the workaround Inside a CAN frame, the longest period that the Rx pin stays in recessive state is 5 bits. At the end of the frame, the time between the acknowledge dominant bit and the end of reception (signaled by REC bit status) is 8tCANbit, therefore the maximum time spent in the workaround is: 8tCANbit+tloop+ttest+trelease in this case or 8tCANbit+25tCPU. At low speed, this time could represent a long delay for the application, therefore it makes sense to evaluate how frequently this delay occurs. Figure 111. Critical Window Timing Diagram
In order to reach the critical FMP = 2, the CAN node needs to receive two messages without servicing them. Then in order to reach the critical window, the cell has to receive a third one and the application has to release the mailbox at the same time, at the end of the reception. In the application, messages are not processed only if either the interrupt are disabled or higher level interrupts are being serviced. Therefore if:
tIT higher level + tIT disable + tIT CAN < 2 x tCAN frame
the application will never wait in the workaround tIT higher level: This the sum of the duration of all the interrupts with a level strictly higher than the CAN interrupt level tIT disable: This is the longest time the application disables the CAN interrupt (or all interrupts) tIT CAN: This is the maximum duration between the beginning of the CAN interrupt and the actual location of the workaround tCAN frame: This is minimum CAN frame duration
CAN Frame
Critical window: the received message is placed in the FIFO
Acknowledge: last dominant bit in the frame
Time to test RX pin and to release the FIFO 4.5s@4 MHz Time between the end of the acknowledge and the critical windows - 6 full CAN bit times + time to the sample point approx. 13s @ 500 Kbaud
A release is not allowed at this time
Figure 112. Reception of a Sequence of Frames FMP BUS CPU 0 tCAN frame 1 1 tCAN frame 2 tIT disable 2 tCAN frame 3 tIT higher level tIT CAN 2
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beCAN CONTROLLER (Cont'd) Side-effect of Workround 1 Because the while loop lasts 10 CPU cycles, at high baud rate, it is possible to miss a dominant state on the bus if it lasts just one CAN bit time and the bus speed is high enough (see Table 1). Table 29. While Loop Timing
fCPU 8 MHz 4 MHz fCPU Software timing: While loop 1.25 s 2.5 s 10/fCPU Minimum baud rate for possible missed dominant bit 800 Kbaud 400 Kbaud fCPU/10
If this happens, we will continue waiting in the while loop instead of releasing the FIFO immediately. The workaround is still valid because we will not release the FIFO during the critical period. But the application may lose additional time waiting in the while loop as we are no longer able to guarantee a maximum of 6 CAN bit times spent in the workaround. In this particular case the time the application can spend in the workaround may increase up to a full CAN frame, depending of the frame contents. This
case is very rare but happens when a specific sequence is present on in the CAN frame. The example in Figure 20 shows reception at maximum CAN baud rate: In this case tCAN is 8/fCPU and the sampling time is 10/fCPU. If the application is using the maximum baud rate and the possible delay caused by the workaround is not acceptable, there is another workaround which reduces the Rx pin sampling time. Workaround 2 (see Figure 21) first tests that FMP = 2 and the CAN cell is receiving, if not the FIFO can be released immediately. If yes, the program goes through a sequence of test instructions on the RX pin that last longer than the time between the acknowledge dominant bit and the critical time slot. If the Rx pin is in recessive state for more than 8 CAN bit times, it means we are now after the acknowledge and the critical slot. If a dominant bit is read on the bus, we can release the FIFO immediately. This workaround has to be written in assembly language to avoid the compiler optimizing the test sequence. The implementation shown here is for the CAN bus maximum speed (1 Mbaud @ 8 MHz CPU clock).
Figure 113. Reception at Maximum CAN Baud Rate
CAN Bus signal Sampling of Rx pin
R R R RDR R R RDR R R RDR R R RDR R R RD
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Figure 114. Workaround 2
Ld And Cp Jrne a, CRFR a,#3 a,#2 _RELEASE
; test FMP=2 ? ; if not release
Btjf
CMSR,#5,_RELEASE ; test if reception on going. ; if not release CDGR,#3,_RELEASE ; sample RX pin for 8 CAN bit time CDGR,#3,_RELEASE CDGR,#3,_RELEASE CDGR,#3,_RELEASE CDGR,#3,_RELEASE CDGR,#3,_RELEASE CDGR,#3,_RELEASE CDGR,#3,_RELEASE CDGR,#3,_RELEASE CDGR,#3,_RELEASE CDGR,#3,_RELEASE CDGR,#3,_RELEASE CDGR,#3,_RELEASE CDGR,#3,_RELEASE
Btjf Btjf Btjf btjf btjf btjf btjf btjf btjf btjf btjf btjf btjf btjf _RELEASE: bset
CRFR,#5
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beCAN CONTROLLER (Cont'd) 10.9.8 Register Description 10.9.8.1 Control and Status Registers CAN MASTER CONTROL REGISTER (CMCR) Reset Value: 0000 0010 (02h)
7 0 ABOM AWUM NART RFLM 0 TXFP SLEEP INRQ
Bit 3 = RFLM Receive FIFO Locked Mode - Read/Set/Clear 0: Receive FIFO not locked on overrun. Once a receive FIFO is full the next incoming message will overwrite the previous one. 1: Receive FIFO locked against overrun. Once a receive FIFO is full the next incoming message will be discarded. Bit 2 = TXFP Transmit FIFO Priority - Read/Set/Clear This bit controls the transmission order when several mailboxes are pending at the same time. 0: Priority driven by the identifier of the message 1: Priority driven by the request order (chronologically) Bit 1 = SLEEP Sleep Mode Request - Read/Set/Clear This bit is set by software to request the CAN hardware to enter the sleep mode. Sleep mode will be entered as soon as the current CAN activity (transmission or reception of a CAN frame) has been completed. This bit is cleared by software to exit sleep mode. This bit is cleared by hardware when the AWUM bit is set and a SOF bit is detected on the CAN Rx signal. Bit 0 = INRQ Initialization Request - Read/Set/Clear The software clears this bit to switch the hardware into normal mode. Once 11 consecutive recessive bits have been monitored on the Rx signal the CAN hardware is synchronized and ready for transmission and reception. Hardware signals this event by clearing the INAK bit if the CMSR register. Software sets this bit to request the CAN hardware to enter initialization mode. Once software has set the INRQ bit, the CAN hardware waits until the current CAN activity (transmission or reception) is completed before entering the initialization mode. Hardware signals this event by setting the INAK bit in the CMSR register.
Bit 7 = Reserved, must be kept cleared. Bit 6 = ABOM Automatic Bus-Off Management - Read/Set/Clear This bit controls the behaviour of the CAN hardware on leaving the Bus-Off state. 0: The Bus-Off state is left on software request. Refer to Section 0.1.4.5 Error Management, Bus-Off recovery. 1: The Bus-Off state is left automatically by hardware once 128 x 11 recessive bits have been monitored. For detailed information on the Bus-Off state please refer to Section 0.1.4.5 Error Management. Bit 5 = AWUM Automatic Wake-Up Mode - Read/Set/Clear This bit controls the behaviour of the CAN hardware on message reception during sleep mode. 0: The sleep mode is left on software request by clearing the SLEEP bit of the CMCR register. 1: The sleep mode is left automatically by hardware on CAN message detection. The SLEEP bit of the CMCR register and the SLAK bit of the CMSR register are cleared by hardware. Bit 4 = NART No Automatic Retransmission - Read/Set/Clear 0: The CAN hardware will automatically retransmit the message until it has been successfully transmitted according to the CAN standard. 1: A message will be transmitted only once, independently of the transmission result (successful, error or arbitration lost).
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beCAN CONTROLLER (Cont'd) CAN MASTER STATUS REGISTER (CMSR) Reset Value: 0000 0010 (02h)
7 0 0 REC TRAN WKUI ERRI SLAK 0 INAK
quest from the software (set SLEEP bit in CMCR register). This bit is cleared by hardware when the CAN hardware has left sleep mode. Sleep mode is left when the SLEEP bit in the CMCR register is cleared. Please refer to the AWUM bit of the CMCR register description for detailed information for clearing SLEEP bit. Bit 0 = INAK Initialization Acknowledge - Read This bit is set by hardware and indicates to the software that the CAN hardware is now in initialization mode. This bit acknowledges the initialization request from the software (set INRQ bit in CMCR register). This bit is cleared by hardware when the CAN hardware has left the initialization mode and is now synchronized on the CAN bus. To be synchronized the hardware has to monitor a sequence of 11 consecutive recessive bits on the CAN RX signal. CAN TRANSMIT STATUS REGISTER (CTSR) Read / Write ( Reset Value: 0000 0000 (00h)
7 0 0 TXOK1 TXOK0 0
0
Note: To clear a bit of this register the software must write this bit with a one. Bits 7:4 = Reserved. Forced to 0 by hardware. Bit 5 = REC Receive - Read The CAN hardware is currently receiver. Bit 4 = TRAN Transmit - Read The CAN hardware is currently transmitter. Bit 3 = WKUI Wake-Up Interrupt - Read/Clear This bit is set by hardware to signal that a SOF bit has been detected while the CAN hardware was in sleep mode. Setting this bit generates a status change interrupt if the WKUIE bit in the CIER register is set. This bit is cleared by software. Bit 2 = ERRI Error Interrupt - Read/Clear This bit is set by hardware when a bit of the CESR has been set on error detection and the corresponding interrupt in the CEIER is enabled. Setting this bit generates a status change interrupt if the ERRIE bit in the CIER register is set. This bit is cleared by software. Bit 1 = SLAK Sleep Acknowledge - Read This bit is set by hardware and indicates to the software that the CAN hardware is now in sleep mode. This bit acknowledges the sleep mode re-
0
RQCP1 RQCP0
Note: To clear a bit of this register the software must write this bit with a one. Bits 7:6 = Reserved. Forced to 0 by hardware. Bit 5 = TXOK1 Transmission OK for mailbox 1 - Read This bit is set by hardware when the transmission request on mailbox 1 has been completed successfully. Please refer to Figure 7. This bit is cleared by hardware when mailbox 1 is requested for transmission or when the software clears the RQCP1 bit.
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beCAN CONTROLLER (Cont'd) Bit 4 = TXOK0 Transmission OK for mailbox 0 - Read This bit is set by hardware when the transmission request on mailbox 0 has been completed successfully. Please refer to Figure 7. This bit is cleared by hardware when mailbox 0 is requested for transmission or when the software clears the RQCP0 bit. Bits 3:2 = Reserved. Forced to 0 by hardware. Bit 1 = RQCP1 Request Completed for Mailbox 1 - Read/Clear This bit is set by hardware to signal that the last request for mailbox 1 has been completed. The request could be a transmit or an abort request. This bit is cleared by software. Bit 0 = RQCP0 Request Completed for Mailbox 0 - Read/Clear This bit is set by hardware to signal that the last request for mailbox 0 has been completed. The request could be a transmit or an abort request. This bit is cleared by software. CAN TRANSMIT PRIORITY REGISTER (CTPR) All bits of this register are read only. Reset Value: 0000 1100 (0Ch)
7
0 LOW1 LOW0 0 TME1 TME0 0
mailbox are pending for transmission and mailbox 1 has the lowest priority. Bit 5 = LOW0 Lowest Priority Flag for Mailbox 0 - Read This bit is set by hardware when more than one mailbox are pending for transmission and mailbox 0 has the lowest priority. Note: These bits are set to zero when only one mailbox is pending. Bit 4 = Reserved. Forced to 0 by hardware. Bit 3 = TME1 Transmit Mailbox 1 Empty - Read This bit is set by hardware when no transmit request is pending for mailbox 1. Bit 2 = TME0 Transmit Mailbox 0 Empty - Read This bit is set by hardware when no transmit request is pending for mailbox 0. Bit 1:0 = CODE Mailbox Code - Read In case at least one transmit mailbox is free, the code value is equal to the number of the next transmit mailbox free. In case all transmit mailboxes are pending, the code value is equal to the number of the transmit mailbox with the lowest priority.
0
CODE
Bit 7 = Reserved. Forced to 0 by hardware. Bit 6 = LOW1 Lowest Priority Flag for Mailbox 1 - Read This bit is set by hardware when more than one
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beCAN CONTROLLER (Cont'd) CAN RECEIVE FIFO REGISTERS (CRFR) Read / Write Reset Value: 0000 0000 (00h)
7 0 0 RFOM FOVR FULL 0 FMP1 0 FMP0
These bits indicate how many messages are pending in the receive FIFO. FMP is increased each time the hardware stores a new message in to the FIFO. FMP is decreased each time the software releases the output mailbox by setting the RFOM bit. CAN INTERRUPT ENABLE REGISTER (CIER) All bits of this register are set and cleared by software. Read / Write Reset Value: 0000 0000 (00h)
7
WKUIE 0 0 0 FOVIE0 FFIE0 FMPIE0
Note: To clear a bit in this register, software must write a "1" to the bit. Bits 7:6 = Reserved. Forced to 0 by hardware. Bit 5 = RFOM Release FIFO Output Mailbox - Read/Set Set by software to release the output mailbox of the FIFO. The output mailbox can only be released when at least one message is pending in the FIFO. Setting this bit when the FIFO is empty has no effect. If more than one message are pending in the FIFO, the software has to release the output mailbox to access the next message. Cleared by hardware when the output mailbox has been released. Bit 4 = FOVR FIFO Overrun - Read/Clear This bit is set by hardware when a new message has been received and passed the filter while the FIFO was full. This bit is cleared by software. Bit 3 = FULL FIFO Full - Read/Clear Set by hardware when three messages are stored in the FIFO. This bit can be cleared by software writing a one to this bit or releasing the FIFO by means of RFOM. Bit 2 = Reserved. Forced to 0 by hardware. Bits 1:0 = FMP[1:0] FIFO Message Pending - Read
0
TMEIE
Bit 7 = WKUIE Wake-Up Interrupt Enable 0: No interrupt when WKUI is set. 1: Interrupt generated when WKUI bit is set. Bits 6:4 = Reserved. Forced to 0 by hardware. Bit 3 = FOVIE FIFO Overrun Interrupt Enable 0: No interrupt when FOVR bit is set. 1: Interrupt generated when FOVR bit is set. Bit 2 = FFIE FIFO Full Interrupt Enable 0: No interrupt when FULL bit is set. 1: Interrupt generated when FULL bit is set. Bit 1 = FMPIE FIFO Message Pending Interrupt Enable 0: No interrupt on FMP[1:0] bits transition from 00b to 01b. 1: Interrupt generated on FMP[1:0] bits transition from 00b to 01b. Bit 0 = TMEIE Transmit Mailbox Empty Interrupt Enable 0: No interrupt when RQCPx bit is set. 1: Interrupt generated when RQCPx bit is set.
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beCAN CONTROLLER (Cont'd) CAN ERROR STATUS REGISTER (CESR) Read / Write Reset Value: 0000 0000 (00h)
7 0 LEC2 LEC1 LEC0 0 BOFF 0 EPVF EWGF
Bit 1 = EWGF Error Warning Flag - Read This bit is set by hardware when the warning limit has been reached. Receive Error Counter or Transmit Error Counter greater than 96. CAN ERROR INTERRUPT ENABLE REGISTER (CEIER) All bits of this register are set and clear by software. Read/Write Reset Value: 0000 0000 (00h)
7 ERRIE 0 0 LECIE 0 0 BOFIE EPVIE EWGIE
Bit 7 = Reserved. Forced to 0 by hardware. Bits 6:4 = LEC[2:0] Last Error Code - Read/Set/Clear This field holds a code which indicates the type of the last error detected on the CAN bus. If a message has been transferred (reception or transmission) without error, this field will be cleared to `0'. The code 7 is unused and may be written by the CPU to check for update Table 30. LEC Error Types
Code 0 1 2 3 4 5 6 7 Error Type No Error Stuff Error Form Error Acknowledgment Error Bit recessive Error Bit dominant Error CRC Error Set by software
Bit 7 = ERRIE Error Interrupt Enable 0: No interrupt will be generated when an error condition is pending in the CESR. 1: An interrupt will be generation when an error condition is pending in the CESR. Bits 6:5 = Reserved. Forced to 0 by hardware. Bit 4 = LECIE Last Error Code Interrupt Enable 0: ERRI bit will not be set when the error code in LEC[2:0] is set by hardware on error detection. 1: ERRI bit will be set when the error code in LEC[2:0] is set by hardware on error detection. Bit 3 = Reserved. Forced to 0 by hardware.
Bit 3 = Reserved. Forced to 0 by hardware. Bit 2 = BOFF Bus-Off Flag - Read This bit is set by hardware when it enters the busoff state. The bus-off state is entered on TECR overrun, TEC greater than 255, refer to section 0.1.4.5 on page 14. Bit 1 = EPVF Error Passive Flag - Read This bit is set by hardware when the Error Passive limit has been reached (Receive Error Counter or Transmit Error Counter greater than 127).
Bit 2 = BOFIE Bus-Off Interrupt Enable 0: ERRI bit will not be set when BOFF is set. 1: ERRI bit will be set when BOFF is set. Bit 1 = EPVIE Error Passive Interrupt Enable 0: ERRI bit will not be set when EPVF is set. 1: ERRI bit will be set when EPVF is set. Bit 0 = EWGIE Error Warning Interrupt Enable 0: ERRI bit will not be set when EWGF is set. 1: ERRI bit will be set when EWGF is set.
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beCAN CONTROLLER (Cont'd) TRANSMIT ERROR COUNTER REG. (TECR) Read Only Reset Value: 00h
7 TEC7 TEC6 TEC5 TEC4 TEC3 TEC2 TEC1 0 TEC0
Bit 1 = SILM Silent Mode - Read/Set/Clear 0: Normal operation 1: Silent Mode Bit 0 = LBKM Loop Back Mode - Read/Set/Clear 0: Loop Back Mode disabled 1: Loop Back Mode enabled CAN BIT TIMING REGISTER 0 (CBTR0) This register can only be accessed by the software when the CAN hardware is in configuration mode. Read / Write Reset Value: 0000 0000 (00h)
TEC[7:0] is the least significant byte of the 9-bit Transmit Error Counter implementing part of the fault confinement mechanism of the CAN protocol. RECEIVE ERROR COUNTER REG. (RECR) Page: 00h -- Read Only Reset Value: 00h
7 REC7 REC6 REC5 REC4 REC3 REC2 REC1 0 REC0
7 SJW1 SJW0 BRP5 BRP4 BRP3 BRP2 BRP1
0 BRP0
REC[7:0] is the Receive Error Counter implementing part of the fault confinement mechanism of the CAN protocol. In case of an error during reception, this counter is incremented by 1 or by 8 depending on the error condition as defined by the CAN standard. After every successful reception the counter is decremented by 1 or reset to 120 if its value was higher than 128. When the counter value exceeds 127, the CAN controller enters the error passive state. CAN DIAGNOSIS REGISTER (CDGR) All bits of this register are set and clear by software. Read / Write Reset Value: 0000 1100 (0Ch)
7 0 0 0 0 RX SAMP SILM 0
Bit 7:6 SJW[1:0] Resynchronization Jump Width These bits define the maximum number of time quanta the CAN hardware is allowed to lengthen or shorten a bit to perform the resynchronization. Resynchronization Jump Width = (SJW+1). Bit 5:0 BRP[5:0] Baud Rate Prescaler These bits define the length of a time quantum. tq = (BRP+1)/fCPU For more information on bit timing, please refer to Section 0.1.4.6 Bit Timing. CAN BIT TIMING REGISTER 1 (CBTR1) Read / Write Reset Value: 0001 0011 (23h)
7 0 BS22 BS21 BS20 BS13 BS12 BS11 0 BS10
LBKM
Bit 7 = Reserved. Forced to 0 by hardware. Bit 3 = RX CAN Rx Signal - Read Monitors the actual value of the CAN_RX Pin. Bit 2 = SAMP Last Sample Point - Read The value of the last sample point. Bits 6:4 BS2[2:0] Time Segment 2 These bits define the number of time quanta in Time Segment 2. Time Segment 2 = (BS2+1)
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beCAN CONTROLLER (Cont'd) Bits 3:0 BS1[3:0] Time Segment 1 These bits define the number of time quanta in Time Segment 1 Time Segment 1 = (BS1+1) For more information on bit timing, please refer to Section 0.1.4.6 Bit Timing. CAN FILTER PAGE SELECT REGISTER (CPSR) All bits of this register are set and cleared by software. Read / Write Reset Value: 0000 0000 (00h)
7 0 0 0 0 0 FPS2 FPS1 0 FPS0
Bits 7:3 = Reserved. Forced to 0 by hardware. Bits 2:0 = PS[2:0] Page Select - Read/Write This register contains the page number. Table 31. Filter Page Selection
PS[2:0] 0 1 2 3 4 5 6 7 Page Selected Tx Mailbox 0 Tx Mailbox 1 Acceptance Filter 0:1 Acceptance Filter 2:3 Acceptance Filter 4:5 Reserved Configuration/Diagnosis Receive FIFO
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beCAN CONTROLLER (Cont'd) 10.9.8.2 Mailbox Registers This chapter describes the registers of the transmit and receive mailboxes. Refer to Section 0.1.4.4 Message Storage for detailed register mapping. Transmit and receive mailboxes have the same registers except: MCSR register in a transmit mailbox is replaced by MFMI register in a receive mailbox. A receive mailbox is always write protected. A transmit mailbox is write enable only while empty, corresponding TME bit in the CTPR register set. MAILBOX CONTROL STATUS REGISTER (MCSR) Read / Write Reset Value: 0000 0000 (00h)
7 0 0 TERR ALST 0 TXOK RQCP ABRQ TXRQ
Bit 3 = TXOK Transmission OK - Read The hardware updates this bit after each transmission attempt. 0: The previous transmission failed 1: The previous transmission was successful Note: This bit has the same value as the corresponding TXOKx bit in the CTSR register. Bit 2 = RQCP Request Completed - Read/Clear Set by hardware when the last request (transmit or abort) has been performed. Cleared by software writing a "1" or by hardware on transmission request. Note: This bit has the same value as the corresponding RQCPx bit of the CTSR register. Clearing this bit clears all the status bits (TXOK, ALST and TERR) in the MCSR register and the RQCP and TXOK bits in the CTSR register. Bit 1 = ABRQ Abort Request for Mailbox - Read/Set Set by software to abort the transmission request for the corresponding mailbox. Cleared by hardware when the mailbox becomes empty. Setting this bit has no effect when the mailbox is not pending for transmission. Bit 0 = TXRQ Transmit Mailbox Request - Read/Set Set by software to request the transmission for the corresponding mailbox. Cleared by hardware when the mailbox becomes empty. Note: This register is implemented only in transmit mailboxes. In receive mailboxes, the MFMI register is mapped at this location.
Bits 7:6 = Reserved. Forced to 0 by hardware. Bit 5 = TERR Transmission Error - Read This bit is updated by hardware after each transmission attempt. 0: The previous transmission was successful 1: The previous transmission failed due to an error Bit 4 = ALST Arbitration Lost - Read This bit is updated by hardware after each transmission attempt. 0: The previous transmission was successful 1: The previous transmission failed due to an arbitration lost
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beCAN CONTROLLER (Cont'd) MAILBOX FILTER MATCH INDEX (MFMI) This register is read only. Reset Value: 0000 0000 (00h)
7
FMI7 FMI6 FMI5 FMI4 FMI3 FMI2 FMI1
MIDR1
7 0
STID5 FMI0 STID4 STID3 STID2 STID1 STID0 EXID17 EXID16
0
Bits 7:0 = FMI[7:0] Filter Match Index This register contains the index of the filter the message stored in the mailbox passed through. For more details on identifier filtering please refer to Section 0.1.4.3 - Filter Match Index paragraph. Note: This register is implemented only in receive mailboxes. In transmit mailboxes, the MCSR register is mapped at this location. MAILBOX IDENTIFIER REGISTERS (MIDR[3:0]) Read / Write Reset Value: Undefined MIDR0
7
0 IDE RTR STID10 STID9 STID8 STID7
Bits 7:2 = STID[5:0] Standard Identifier 6 least significant bits of the standard part of the identifier. Bits 1:0 = EXID[17:16] Extended Identifier 2 most significant bits of the extended part of the identifier. MIDR2
7
EXID15 EXID14 EXID13 EXID12 EXID11 EXID10 EXID9
0
EXID8
0
STID6
Bits 7:0 = EXID[15:8] Extended Identifier Bits 15 to 8 of the extended part of the identifier. MIDR3
Bit 7 = Reserved. Forced to 0 by hardware.
7 0
EXID6 EXID5 EXID4 EXID3 EXID2 EXID1 EXID0
Bit 6 = IDE Extended Identifier This bit defines the identifier type of message in the mailbox. 0: Standard identifier. 1: Extended identifier. Bit 5 = RTR Remote Transmission Request 0: Data frame 1: Remote frame Bits 4:0 = STID[10:6] Standard Identifier 5 most significant bits of the standard part of the identifier.
EXID7
Bits 7:1 = EXID[6:0] Extended Identifier 6 least significant bits of the extended part of the identifier.
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beCAN CONTROLLER (Cont'd) MAILBOX DATA LENGTH CONTROL REGISTER (MDLC) All bits of this register is write protected when the mailbox is not in empty state. Read / Write Reset Value: xxxx xxxx (xxh)
7
0 0 0 0 DLC3 DLC2 DLC1
MAILBOX DATA REGISTERS (MDAR[7:0]) All bits of this register are write protected when the mailbox is not in empty state. Read / Write Reset Value: Undefined
7
DATA7 DATA6 DATA5 DATA4 DATA3 DATA2 DATA1
0
DATA0
0
DLC0
Bit 7 = Reserved, must be kept cleared. Bits 6:4 = Reserved, forced to 0 by hardware. Bits 3:0 = DLC[3:0] Data Length Code This field defines the number of data bytes a data frame contains or a remote frame request.
Bits 7:0 = DATA[7:0] Data A data byte of the message. A message can contain from 0 to 8 data bytes.
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beCAN CONTROLLER (Cont'd) 10.9.8.3 CAN Filter Registers CAN FILTER CONFIGURATION REG.0 (CFCR0) All bits of this register are set and cleared by software. Read / Write Reset Value: 0000 0000 (00h)
7 0 FSC11 FSC10 FACT1 0 0 FSC01 FSC00 FACT0
CAN FILTER CONFIGURATION REG.1 (CFCR1) All bits of this register are set and cleared by software. Read / Write Reset Value: 0000 0000 (00h)
7 0 FSC31 FSC30 FACT3 0 0 FSC21 FSC20 FACT2
Note: To modify the FFAx and FSCx bits, the beCAN must be in INIT mode. Bit 7 = Reserved. Forced to 0 by hardware. Bits 6:5 = FSC1[1:0] Filter Scale Configuration These bits define the scale configuration of Filter 1. Bit 4 = FACT1 Filter Active The software sets this bit to activate Filter 1. To modify the Filter 1 registers (CF1R[7:0]), the FACT1 bit must be cleared. 0: Filter 1 is not active 1: Filter 1 is active Bit 3 = Reserved. Forced to 0 by hardware. Bits 2:1 = FSC0[1:0] Filter Scale Configuration These bits define the scale configuration of Filter 0. Bit 0 = FACT0 Filter Active The software sets this bit to activate Filter 0. To modify the Filter 0 registers (CF0R[0:7]), the FACT0 bit must be cleared. 0: Filter 0 is not active 1: Filter 0 is active
Bit 7 = Reserved. Forced to 0 by hardware. Bits 6:5 = FSC3[1:0] Filter Scale Configuration These bits define the scale configuration of Filter 3. Bit 4 = FACT3 Filter Active The software sets this bit to activate filter 3. To modify the Filter 3 registers (CF3R[0:7]) the FACT3 bit must be cleared. 0: Filter 3 is not active 1: Filter 3 is active Bit 3 = Reserved. Forced to 0 by hardware. Bits 2:1 = FSC2[1:0] Filter Scale Configuration These bits define the scale configuration of Filter 2. Bit 0 = FACT2 Filter Active The software sets this bit to activate Filter 2. To modify the Filter 2 registers (CF2R[0:7]), the FACT2 bit must be cleared. 0: Filter 2 is not active 1: Filter 2 is active
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beCAN CONTROLLER (Cont'd) CAN FILTER CONFIGURATION REG.1 (CFCR2) All bits of this register are set and cleared by software. Read / Write Reset Value: 0000 0000 (00h)
7 0 FSC51 FSC50 FACT5 0 0 FSC41 FSC40 FACT4
CAN FILTER MODE REGISTER (CFMR0) All bits of this register are set and cleared by software. Read / Write Reset Value: 0000 0000 (00h)
7 FMH3 FML3 FMH2 FML2 FMH1 FML1 FMH0 0 FML0
Bit 7 = Reserved. Forced to 0 by hardware. Bits 6:5 = FSC5[1:0] Filter Scale Configuration These bits define the scale configuration of Filter 5. Bit 4 = FACT5 Filter Active The software sets this bit to activate filter 5. To modify the Filter 5 registers (CF5R[0:7]) the FACT5 bit must be cleared. 0: Filter 5 is not active 1: Filter 5 is active Bit 3 = Reserved. Forced to 0 by hardware. Bits 2:1 = FSC4[1:0] Filter Scale Configuration These bits define the scale configuration of Filter 4. Bit 0 = FACT4 Filter Active The software sets this bit to activate Filter 4. To modify the Filter 4 registers (CF4R[0:7]), the FACT4 bit must be cleared. 0: Filter 4 is not active 1: Filter 4 is active
Bit 7 = FMH3 Filter Mode High Mode of the high registers of Filter 3. 0: High registers are in mask mode 1: High registers are in identifier list mode Bit 6 = FML3 Filter Mode Low Mode of the low registers of Filter 3. 0: Low registers are in mask mode 1: Low registers are in identifier list mode Bit 5 = FMH2 Filter Mode High Mode of the high registers of Filter 2. 0: High registers are in mask mode 1: High registers are in identifier list mode Bit 4 = FML2 Filter Mode Low Mode of the low registers of Filter 2. 0: Low registers are in mask mode 1: Low registers are in identifier list mode Bit 3 = FMH1 Filter Mode High Mode of the high registers of Filter 1. 0: High registers are in mask mode 1: High registers are in identifier list mode Bit 2 = FML1 Filter Mode Low Mode of the low registers of filter 1. 0: Low registers are in mask mode 1: Low registers are in identifier list mode Bit 1 = FMH0 Filter Mode High Mode of the high registers of filter 0. 0: High registers are in mask mode 1: High registers are in identifier list mode Bit 0 = FML0 Filter Mode Low Mode of the low registers of filter 0. 0: Low registers are in mask mode 1: Low registers are in identifier list mode
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beCAN CONTROLLER (Cont'd) CAN FILTER MODE REGISTER (CFMR1) All bits of this register are set and cleared by software. Read / Write Reset Value: 0000 0000 (00h)
7 0 0 0 0 FMH5 FML5 FMH4 0 FML4
FILTER x REGISTER[7:0] (CFxR[7:0]) Read / Write Reset Value: Undefined
7
FB7 FB6 FB5 FB4 FB3 FB2 FB1
0
FB0
Bits 7:4 = Reserved. Forced to 0 by hardware. Bit 3 = FMH5 Filter Mode High Mode of the high registers of Filter 5. 0: High registers are in mask mode 1: High registers are in identifier list mode Bit 2 = FML5 Filter Mode Low Mode of the low registers of filter 5. 0: Low registers are in mask mode 1: Low registers are in identifier list mode Bit 1 = FMH4 Filter Mode High Mode of the high registers of filter 4. 0: High registers are in mask mode 1: High registers are in identifier list mode Bit 0 = FML4 Filter Mode Low Mode of the low registers of filter 4. 0: Low registers are in mask mode 1: Low registers are in identifier list mode
In all configurations: Bits 7:0 = FB[7:0] Filter Bits Identifier Each bit of the register specifies the level of the corresponding bit of the expected identifier. 0: Dominant bit is expected 1: Recessive bit is expected Mask Each bit of the register specifies whether the bit of the associated identifier register must match with the corresponding bit of the expected identifier or not. 0: Don't care, the bit is not used for the comparison 1: Must match, the bit of the incoming identifier must have the same level has specified in the corresponding identifier register of the filter. Note: Each filter x is composed of 8 registers, CFxR[7:0]. Depending on the scale and mode configuration of the filter the function of each register can differ. For the filter mapping, functions description and mask registers association, refer to Section 0.1.4.3 Identifier Filtering. A Mask/Identifier register in mask mode has the same bit mapping as in identifier list mode. Note: To modify these registers, the corresponding FACT bit in the CFCR register must be cleared.
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beCAN CONTROLLER (Cont'd) Figure 115. CAN Register Mapping
68h 69h 6Ah 6Bh 6Ch 6Dh 6Eh 6Fh CAN MASTER CONTROL REGISTER CAN MASTER STATUS REGISTER CAN TRANSMIT STATUS REGISTER CAN TRANSMIT PRIORITY REGISTER CAN RECEIVE FIFO REGISTER CAN INTERRUPT ENABLE REGISTER CAN DIAGNOSIS REGISTER CAN PAGE SELECTION REGISTER CMCR CMSR CTSR CTPR CRFR CIER CDGR CPSR
PAGED REGISTER 0 PAGED REGISTER 1 PAGED REGISTER 2 PAGED REGISTER 3 PAGED REGISTER 4 PAGED REGISTER 5 PAGED REGISTER 6 PAGED REGISTER 7 PAGED REGISTER 8 PAGED REGISTER 9 PAGED REGISTER 10 PAGED REGISTER 11 PAGED REGISTER 12 PA XXh GED REGISTER 13 PAGED REGISTER 14 PAGED REGISTER 15
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beCAN CONTROLLER (Cont'd) 10.9.8.4 Page Mapping for CAN
PAGE 0 70h 71h 72h 73h 74h 75h 76h 77h 78h 79h 7Ah 7Bh 7Ch 7Dh 7Eh 7Fh MCSR MDLC MIDR0 MIDR1 MIDR2 MIDR3 MDAR0 MDAR1 MDAR2 MDAR3 MDAR4 MDAR5 MDAR6 MDAR7 MTSLR MTSHR Tx Mailbox 0 PAGE 6 70h 71h 72h 73h 74h 75h 76h 77h 78h 79h 7Ah 7Bh 7Ch 7Dh 7Eh 7Fh CESR CEIER TECR RECR BTCR0 BTCR1 Reserved Reserved CFMR0 CFMR1 CFCR0 CFCR1 CFCR2 Reserved Reserved Reserved Configuration/Diagnosis PAGE 1 MCSR MDLC MIDR0 MIDR1 MIDR2 MIDR3 MDAR0 MDAR1 MDAR2 MDAR3 MDAR4 MDAR5 MDAR6 MDAR7 MTSLR MTSHR Tx Mailbox 1 PAGE 7 MFMI MDLC MIDR0 MIDR1 MIDR2 MIDR3 MDAR0 MDAR1 MDAR2 MDAR3 MDAR4 MDAR5 MDAR6 MDAR7 MTSLR MTSHR Receive FIFO PAGE 2 CF0R0 CF0R1 CF0R2 CF0R3 CF0R4 CF0R5 CF0R6 CF0R7 CF1R0 CF1R1 CF1R2 CF1R3 CF1R4 CF1R5 CF1R6 CF1R7 Acceptance Filter 0:1 PAGE 3 CF2R0 CF2R1 CF2R2 CF2R3 CF2R4 CF2R5 CF2R6 CF2R7 CF3R0 CF3R1 CF3R2 CF3R3 CF3R4 CF3R5 CF3R6 CF3R7 Acceptance Filter 2:3 PAGE 4 CF4R0 CF4R1 CF4R2 CF4R3 CF4R4 CF4R5 CF4R6 CF4R7 CF5R0 CF5R1 CF5R2 CF5R3 CF5R4 CF5R5 CF5R6 CF5R7 Acceptance Filter 4:5
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beCAN CONTROLLER (Cont'd) Table 32. beCAN Control and Status Page - Register Map and Reset Values
Address (Hex.) 68h 69h 6Ah 6Bh 6Ch 6Dh 6Eh 6Fh Register Name CMCR Reset Value CMSR Reset Value CTSR Reset Value CTPR Reset Value CRFR Reset Value CIER Reset Value CDGR Reset Value CFPS R Reset Value 0 0 0 0 0 0 0 0 0 0 W KUI E 0 0 0 0 0 0 LOW 1 0 0 0 0 7 6 ABOM 0 5 AW UM 0 REC 0 TXOK1 0 LO W0 0 RFO M 0 0 1 FOVR 0 0 4 NART 0 TRAN 0 TX OK0 0 0 TME1 1 FULL 0 FOVIE0 0 RX 1 0 FFIE0 0 SAM P 1 FP S2 0 0 TM E0 1 0 FMP1 0 FMPIE0 0 SILM 0 FPS1 0 3 RFLM 0 WK UI 0 2 TXFP 0 ERRI 0 1 SLEEP 1 SLAK 1 RQC P1 0 0 INRQ 0 INAK 0 R QC P 0 0 C OD E 0 0 FMP0 0 TMEIE 0 LBKM 0 FPS0 0
Table 33. beCAN Mailbox Pages - Register Map and Reset Values
Address (Hex.) 70h Receive 70h Transmit 71h 72h 73h 74h 75h 76h:7Dh Register Name MFMI Reset Value MCSR Reset Value MDLC Reset Value MIDR0 Reset Value MIDR1 Reset Value MIDR2 Reset Value MIDR3 Reset Value MDAR [0:7] Reset Value x STID5 x EXID15 x EXID7 x MD AR7 x 0 0 x x IDE x STID4 x EXID14 x EXID6 x M DAR6 x x RTR x STID3 x EXID13 x EX ID5 x MDAR 5 x x STID10 x STID 2 x EX ID12 x EXID 4 x M DAR4 x 0 7 FMI7 0 6 FM I6 0 5 FMI5 0 TE RR 0 4 FM I4 0 ALST 0 3 FM I3 0 TXOK 0 DLC3 x STID 9 x STID 1 x EXID11 x EXID 3 x M DAR3 x 2 FMI2 0 RQ CP 0 DLC2 x STID8 x STID0 x EXID10 x EXID2 x MDAR2 x 1 FMI1 0 ABRQ 0 DLC1 x STID7 x EXID17 x EXID9 x EXID1 x MDA R1 x 0 FM I0 0 TXRQ 0 DLC0 x STID 6 x EX ID16 x EXID8 x EXID0 x M DAR0 x
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Address (Hex.) 7Eh 7Fh
Register Name MTS LR Reset Value MTSH R Reset Value
7 TIME7 x TIM E 15 x
6 TIM E 6 x TIME14 x
5 TIME5 x TIM E 13 x
4 TIME4 x TIME12 x
3 TIME3 x TIME11 x
2 TIME2 x TIME10 x
1 TIM E 1 x TIM E 9 x
0 TIME0 x TIME8 x
Table 34. beCAN Filter Configuration Page - Register Map and Reset Values
Address (Hex.) 70h 71h 72h 73h 74h 75h 76h 77h 78h 79h 7Ah 7Bh 7Ch Register Name CESR Reset Value CEIER Reset Value TECR Reset Value RECR Reset Value CBTR0 Reset Value CBTR1 Reset Value Reserved Reserved CFM R0 Reset Value CFM R1 Reset Value CFCR 0 Reset Value CFCR 1 Reset Value CFCR 2 Reset Value 0 x x FMH3 0 0 FFA1 0 FFA3 0 FFA5 0 0
ERRIE
7
6 LEC2 0 0 TEC6 0 REC 6 0 SJW 0 0 BS22 0 x x FML3 0 0 FSC11 0 FSC31 0 FSC51 0
5 LEC1 0 0 TEC5 0 R EC5 0 B RP5 0 BS21 1 x x FM H2 0 0 FSC10 0 FSC30 0 FSC50 0
4 LEC0 0 LECIE 0 TEC4 0 REC4 0 BRP4 0 BS20 0 x x FML2 0 0 FACT1 0 FACT3 0 FACT5 0
3
2 BO FF
1 EPVF 0 EP VIE 0 TEC1 0 REC1 0 BRP1 0 BS11 1 x x FMH0 0 FMH4 0 FSC00 0 FSC20 0 FSC40 0
0 EWG F 0 E WG I E 0 TEC0 0 REC0 0 BRP0 0 BS10 1 x x FML0 0 FML4 0 FACT0 0 FACT2 0 FACT4 0
0 0 TEC3 0 REC3 0 BRP3 0 BS13 0 x x FMH1 0 FMH5 0 FFA0 0 FFA2 0 FFA4 0
0 BOFIE 0 TEC 2 0 RE C2 0 BR P2 0 B S1 2 0 x x FM L1 0 FM L5 0 FSC01 0 FSC21 0 FSC41 0
0 TEC7 0 REC7 0 SJW1 0
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10.10 10-BIT A/D CONVERTER (ADC) 10.10.1 Introduction The on-chip Analog to Digital Converter (ADC) peripheral is a 10-bit, successive approximation converter with internal sample and hold circuitry. This peripheral has up to 16 multiplexed analog input channels (refer to device pin out description) that allow the peripheral to convert the analog voltage levels from up to 16 different sources. The result of the conversion is stored in a 10-bit Data Register. The A/D converter is controlled through a Control/Status Register. 10.10.2 Main Features 10-bit conversion Up to 16 channels with multiplexed input Linear successive approximation Data register (DR) which contains the results Conversion complete status flag On/off bit (to reduce consumption) The block diagram is shown in Figure 116. Figure 116. ADC Block Diagram f CPU fCPU, fCPU/2, fCPU/4 fADC 10.10.3 Functional Description 10.10.3.1 Digital A/D Conversion Result The conversion is monotonic, meaning that the result never decreases if the analog input does not and never increases if the analog input does not. If the input voltage (VAIN) is greater than VDDA (high-level voltage reference) then the conversion result is FFh in the ADCDRH register and 03h in the ADCDRL register (without overflow indication). If the input voltage (VAIN) is lower than VSSA (lowlevel voltage reference) then the conversion result in the ADCDRH and ADCDRL registers is 00 00h. The A/D converter is linear and the digital result of the conversion is stored in the ADCDRH and ADCDRL registers. The accuracy of the conversion is described in the Electrical Characteristics Section. RAIN is the maximum recommended impedance for an analog input signal. If the impedance is too high, this will result in a loss of accuracy due to leakage and sampling not being completed in the allotted time.
EOC SPEED ADON SLOW CH3
CH2
CH1
CH0
AD CCSR
4
AIN0
AIN1
ANALOG MUX
AINx
ANALOG TO DIGITAL CONVERTER
A DCD RH
D9
D8
D7
D6
D5
D4
D3
D2
AD CDR L
0
0
0
0
0
0
D1
D0
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10-BIT A/D CONVERTER (ADC) (Cont'd) 10.10.3.2 A/D Conversion The analog input ports must be configured as input, no pull-up, no interrupt. Refer to the "I/O ports" chapter. Using these pins as analog inputs does not affect the ability of the port to be read as a logic input. In the ADCCSR register: Select the CS[3:0] bits to assign the analog channel to convert. ADC Conversion mode In the ADCCSR register: Set the ADON bit to enable the A/D converter and to start the conversion. From this time on, the ADC performs a continuous conversion of the selected channel. When a conversion is complete: The EOC bit is set by hardware. The result is in the ADCDR registers. A read to the ADCDRH resets the EOC bit. To read the 10 bits, perform the following steps: 1. Poll EOC bit 2. Read the ADCDRL register 3. Read the ADCDRH register. This clears EOC automatically. To read only 8 bits, perform the following steps: 1. Poll EOC bit 2. Read the ADCDRH register. This clears EOC automatically. 10.10.3.3 Changing the conversion channel The application can change channels during conversion. When software modifies the CH[3:0] bits in the ADCCSR register, the current conversion is stopped, the EOC bit is cleared, and the A/D converter starts converting the newly selected channel. 10.10.3.4 ADCDR consistency If an End Of Conversion event occurs after software has read the ADCDRLSB but before it has read the ADCDRMSB, there would be a risk that the two values read would belong to different samples. To guarantee consistency: The ADCDRL and the ADCDRH registers are locked when the ADCCRL is read The ADCDRL and the ADCDRH registers are unlocked when the ADCDRH register is read or when ADON is reset. This is important, as the ADCDR register will not be updated until the ADCDRH register is read. 10.10.4 Low Power Modes Note: The A/D converter may be disabled by resetting the ADON bit. This feature allows reduced power consumption when no conversion is needed and between single shot conversions. Mode WAIT Description No effect on A/D Converter A/D Converter disabled. After wakeup from Halt mode, the A/D Converter requires a stabilization time tSTAB (see Electrical Characteristics) before accurate conversions can be performed.
H AL T
10.10.5 Interrupts None.
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10-BIT A/D CONVERTER (ADC) (Cont'd) 10.10.6 Register Description CONTROL/STATUS REGISTER (ADCCSR) Read / Write (Except bit 7 read only) Reset Value: 0000 0000 (00h)
7
EOC SPEED ADON SLOW CH3 CH2 CH1
Channel Pin* AIN0 AIN1 AIN2 AIN3 AIN4 AIN5 AIN6 AIN7 AIN8 AIN9 AIN10 AIN11 AIN12 AIN13 AIN14 AIN15
CH3 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1
CH2 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1
CH1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1
CH0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
0
CH0
Bit 7 = EOC End of Conversion This bit is set by hardware. It is cleared by software reading the ADCDRH register or writing to any bit of the ADCCSR register. 0: Conversion is not complete 1: Conversion complete Bit 6 = SPEED A/D clock selection This bit is set and cleared by software. Table 35. A/D Clock Selection
fADC fCPU/2 fCPU (where fCPU <= 4 MHz) fCPU/4 fCPU/2 (same frequency as SLOW=0, SPEED=0) SLOW 0 0 1 1 SPEED 0 1 0 1
DATA REGISTER (ADCDRH) Read Only Reset Value: 0000 0000 (00h)
7
D9 D8 D7 D6 D5 D4 D3
0
D2
Bit 5 = ADON A/D Converter on This bit is set and cleared by software. 0: Disable ADC and stop conversion 1: Enable ADC and start conversion Bit 4 = SLOW A/D Clock Selection This bit is set and cleared by software. It works together with the SPEED bit. Refer to Table 35. Bits 3:0 = CH[3:0] Channel Selection These bits are set and cleared by software. They select the analog input to convert.
*The number of channels is device dependent. Refer to the device pinout description.
Bits 7:0 = D[9:2] MSB of Analog Converted Value DATA REGISTER (ADCDRL) Read Only Reset Value: 0000 0000 (00h)
7
0 0 0 0 0 0 D1
0
D0
Bits 7:2 = Reserved. Forced by hardware to 0. Bits 1:0 = D[1:0] LSB of Analog Converted Value
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10-BIT A/D CONVERTER (ADC) (Cont'd) Table 36. ADC Register Map and Reset Values
Address (Hex.) 45h 46h 47h Register Label ADCCSR Reset Value ADCDRH Reset Value ADCDRL Reset Value 7 EO C 0 D9 0 0 0 6 SP EED 0 D8 0 0 0 5 ADON 0 D7 0 0 0 4 SLOW 0 D6 0 0 0 3 CH3 0 D5 0 0 0 2 CH2 0 D4 0 0 0 1 CH1 0 D3 0 D1 0 0 CH0 0 D2 0 D0 0
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11 INSTRUCTION SET
11.1 CPU ADDRESSING MODES The CPU features 17 different addressing modes which can be classified in seven main groups:
Addressing Mode Inherent Im mediate Direct Indexed Indirect Relative Bit operation Example nop ld A,#$55 ld A,$55 ld A,($55,X) ld A,([$55],X) jrne loop bset byte,#5
The CPU Instruction set is designed to minimize the number of bytes required per instruction: To do Table 37. CPU Addressing Mode Overview
M ode Inherent Im mediate Short Long No Offset Short Long Short Long Short Long Relative Relative Bit Bit Bit Bit Direct Direct Direct Direct Direct Indirect Indirect Indirect Indirect Direct Indirect Direct Indirect Direct Indirect Relative Relative Indexed Indexed Indexed Indexed Indexed nop ld A,#$55 ld A,$10 ld A,$1000 ld A,(X) ld A,($10,X) ld A,($1000,X) ld A,[$10] ld A,[$10.w] ld A,([$10],X) ld A,([$10.w],X) jrne loop jrne [$10] bset $10,#7 bset [$10],#7 btjt $10,#7,skip btjt [$10],#7,skip Syntax
so, most of the addressing modes may be subdivided in two submodes called long and short: Long addressing mode is more powerful because it can use the full 64 Kbyte address space, however it uses more bytes and more CPU cycles. Short addressing mode is less powerful because it can generally only access page zero (0000h 00FFh range), but the instruction size is more compact, and faster. All memory to memory instructions use short addressing modes only (CLR, CPL, NEG, BSET, BRES, BTJT, BTJF, INC, DEC, RLC, RRC, SLL, SRL, SRA, SWAP) The ST7 Assembler optimizes the use of long and short addressing modes.
Destination
Pointer Address (Hex.)
Pointer Size (Hex.)
Length (Bytes) +0 +1
00..FF 0000..FFFF 00..FF 00..1FE 0000..FFFF 00..FF 0000..FFFF 00..1FE 0000..FFFF PC+/-127 PC+/-127 00..FF 00..FF 00..FF 00..FF 00..FF byte 00..FF byte 00..FF byte 00..FF 00..FF 00..FF 00..FF byte word byte word
+1 +2 +0 +1 +2 +2 +2 +2 +2 +1 +2 +1 +2 +2 +3
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INSTRUCTION SET OVERVIEW (Cont'd) 11.1.1 Inherent All Inherent instructions consist of a single byte. The opcode fully specifies all the required information for the CPU to process the operation.
Inherent Instruction NOP TRAP WFI HALT RET IRET SIM RIM SCF RCF RSP LD CLR PUSH/POP INC/DEC TNZ CPL, NEG MUL SLL, SRL, SRA, RLC, RRC SW AP Function No operation S/W Interrupt Wait For Interrupt (Low Power Mode) Halt Oscillator (Lowest Power Mode) Sub-routine Return Interrupt Sub-routine Return Set Interrupt Mask (level 3) Reset Interrupt Mask (level 0) Set Carry Flag Reset Carry Flag Reset Stack Pointer Load Clear Push/Pop to/from the stack Increment/Decrem ent Test Negative or Zero 1 or 2 Complement Byte Multiplication Shift and Rotate Operations Swap Nibbles
11.1.3 Direct In Direct instructions, the operands are referenced by their memory address. The direct addressing mode consists of two submodes: Direct (short) The address is a byte, thus requires only one byte after the opcode, but only allows 00 - FF addressing space. Direct (long) The address is a word, thus allowing 64 Kbyte addressing space, but requires 2 bytes after the opcode. 11.1.4 Indexed (No Offset, Short, Long) In this mode, the operand is referenced by its memory address, which is defined by the unsigned addition of an index register (X or Y) with an offset. The indirect addressing mode consists of three submodes: Indexed (No Offset) There is no offset, (no extra byte after the opcode), and allows 00 - FF addressing space. Indexed (Short) The offset is a byte, thus requires only one byte after the opcode and allows 00 - 1FE addressing space. Indexed (long) The offset is a word, thus allowing 64 Kbyte addressing space and requires 2 bytes after the opcode. 11.1.5 Indirect (Short, Long) The required data byte to do the operation is found by its memory address, located in memory (pointer). The pointer address follows the opcode. The indirect addressing mode consists of two submodes: Indirect (short) The pointer address is a byte, the pointer size is a byte, thus allowing 00 - FF addressing space, and requires 1 byte after the opcode. Indirect (long) The pointer address is a byte, the pointer size is a word, thus allowing 64 Kbyte addressing space, and requires 1 byte after the opcode.
11.1.2 Immediate Immediate instructions have 2 bytes, the first byte contains the opcode, the second byte contains the operand value.
Immediate Instruction LD CP BCP AND, OR, XOR ADC, ADD, SUB, SBC Load C o mpare Bit Compare Logical Operations Arithmetic Operations Function
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INSTRUCTION SET OVERVIEW (Cont'd) 11.1.6 Indirect Indexed (Short, Long) This is a combination of indirect and short indexed addressing modes. The operand is referenced by its memory address, which is defined by the unsigned addition of an index register value (X or Y) with a pointer value located in memory. The pointer address follows the opcode. The indirect indexed addressing mode consists of two submodes: Indirect Indexed (Short) The pointer address is a byte, the pointer size is a byte, thus allowing 00 - 1FE addressing space, and requires 1 byte after the opcode. Indirect Indexed (Long) The pointer address is a byte, the pointer size is a word, thus allowing 64 Kbyte addressing space, and requires 1 byte after the opcode. Table 38. Instructions Supporting Direct, Indexed, Indirect and Indirect Indexed Addressing Modes
Long and Short Instructions LD CP AND, OR, XOR ADC, ADD, SUB, SBC BCP Load Compare Logical Operations Arithmetic Additions/Substractions operations Bit Compare Function
11.1.7 Relative mode (Direct, Indirect) This addressing mode is used to modify the PC register value, by adding an 8-bit signed offset to it.
Available Relative Direct/Indirect Instructions JRxx CALLR Function Conditional Jump Call Relative
The relative addressing mode consists of two submodes: Relative (Direct) The offset is following the opcode. Relative (Indirect) The offset is defined in memory, which address follows the opcode.
Short Instructions Only CLR INC, DEC TNZ CPL, NEG BSET, BRES BTJT, BTJF SLL, SRL, SRA, RLC, RRC SW AP CALL, JP Clear
Function Increment/Decrement Test Negative or Zero 1 or 2 Complement Bit Operations Bit Test and Jump Operations Shift and Rotate Operations Swap Nibbles Call or Jump subroutine
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INSTRUCTION SET OVERVIEW (Cont'd) 11.2 INSTRUCTION GROUPS The ST 7 family devices use an Instruction Set consisting of 63 instructions. The instructions may
Load and Transfer Stack operation Increment/Decrement Compare and Tests Logical operations Bit Operation Conditional Bit Test and Branch Arithmetic operations Shift and Rotates Unconditional Jump or Call Conditional Branch Interruption management Condition Code Flag modification LD PUSH INC CP AND BSET BTJT ADC SLL JRA JRxx TRAP SIM WFI RIM HALT SCF IRET RCF CLR POP DEC TNZ OR BRES BTJF ADD SRL JRT SUB SRA JRF SBC RLC JP MUL RRC CALL SW AP CALLR SLA NOP RET BCP XOR CPL NEG RSP
be subdivided into 13 main groups as illustrated in the following table:
Using a prebyte The instructions are described with one to four opcodes. In order to extend the number of available opcodes for an 8-bit CPU (256 opcodes), three different prebyte opcodes are defined. These prebytes modify the meaning of the instruction they precede. The whole instruction becomes: PC-2 End of previous instruction PC-1 Prebyte PC Opcode PC+1 Additional word (0 to 2) according to the number of bytes required to compute the effective address
These prebytes enable instruction in Y as well as indirect addressing modes to be implemented. They precede the opcode of the instruction in X or the instruction using direct addressing mode. The prebytes are: PDY 90 Replace an X based instruction using immediate, direct, indexed, or inherent addressing mode by a Y one. PIX 92 Replace an instruction using direct, direct bit, or direct relative addressing mode to an instruction using the corresponding indirect addressing mode. It also changes an instruction using X indexed addressing mode to an instruction using indirect X indexed addressing mode. PIY 91 Replace an instruction using X indirect indexed addressing mode by a Y one.
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INSTRUCTION SET OVERVIEW (Cont'd)
Mnem o ADC ADD AND BCP BRES BSET BTJF BTJT CALL CALLR CLR CP CPL DEC HALT IRET INC JP JRA JRT JRF JRIH JRIL JRH JRNH JRM JRNM JRMI JRPL JREQ JRNE JRC JRNC JRULT JRUGE JRUGT Description Add with Carry Addition Logical And Bit compare A, Memory Bit Reset Bit Set Jump if bit is false (0) Jump if bit is true (1) Call subroutine Call subroutine relative Clear Arithmetic Compare One Complement Decrement Halt Interrupt routine return Increm ent Absolute Jump Jump relative always Jump relative Never jump Jump if ext. INT pin = 1 Jump if ext. INT pin = 0 Jump if H = 1 Jump if H = 0 Jump if I1:0 = 11 Jump if I1:0 <> 11 Jump if N = 1 (minus) Jump if N = 0 (plus) Jump if Z = 1 (equal) Jump if Z = 0 (not equal) Jump if C = 1 Jump if C = 0 Jump if C = 1 Jump if C = 0 Jump if (C + Z = 0) jrf * (ext. INT pin high) (ext. INT pin low) H=1? H=0? I1:0 = 11 ? I1:0 <> 11 ? N=1? N=0? Z=1? Z=0? C=1? C=0? Unsigned < Jmp if unsigned >= Unsigned > Pop CC, A, X, PC inc X jp [TBL.w] reg, M tst(Reg - M) A = FFH-A dec Y reg, M reg reg, M reg, M 1 I1 H 0 I0 N N Z Z C M 0 N N N 1 Z Z Z C 1 Function/Example A=A+M+C A=A+M A=A.M tst (A . M) bres Byte, #3 bset Byte, #3 btjf Byte, #3, Jmp1 btjt Byte, #3, Jmp1 A A A A M M M M C C Dst Src M M M M I1 H H H I0 N N N N N Z Z Z Z Z C C C
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INSTRUCTION SET OVERVIEW (Cont'd)
Mnem o JRULE LD MUL NEG NOP OR POP PUSH RCF RET RIM RLC RRC RSP SBC SCF SIM SLA SLL SRL SRA SUB SW AP TNZ TRAP WFI XOR Description Jump if (C + Z = 1) Load Multiply Negate (2's compl) No Operation OR operation Pop from the Stack Push onto the Stack Reset carry flag Subroutine Return Enable Interrupts Rotate left true C Rotate right true C Reset Stack Pointer Substract with Carry Set carry flag Disable Interrupts Shift left Arithmetic Shift left Logic Shift right Logic Shift right Arithmetic Substraction SWAP nibbles Test for Neg & Zero S/W trap Wait for Interrupt Exclusive OR A = A XOR M A M I1:0 = 10 (level 0) C <= A <= C C => A => C S = Max allowed A=A-M-C C=1 I1:0 = 11 (level 3) C <= A <= 0 C <= A <= 0 0 => A => C A7 => A => C A=A-M A7-A4 <=> A3-A0 tnz lbl1 S/W interrupt 1 1 1 0 N Z reg, M reg, M reg, M reg, M A reg, M M 1 1 N N 0 N N N N Z Z Z Z Z Z Z C C C C C A M N Z C 1 reg, M reg, M 1 0 N N Z Z C C A=A+M pop reg pop CC push Y C=0 A reg CC M M M M reg, CC 0 I1 H I0 N Z C N Z Function/Example Unsigned <= dst <= src X,A = X * A neg $10 reg, M A, X, Y reg, M M, reg X, Y, A 0 N Z N Z 0 C Dst Src I1 H I0 N Z C
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12 ELECTRICAL CHARACTERISTICS
12.1 PARAMETER CONDITIONS Unless otherwise specified, all voltages are referred to VSS. 12.1.1 Minimum and Maximum Values Unless otherwise specified the minimum and maximum values are guaranteed in the worst conditions of ambient temperature, supply voltage and frequencies by tests in production on 100% of the devices with an ambient temperature at TA = 25C and TA = TAmax (given by the selected temperature range). Data based on characterization results, design simulation and/or technology characteristics are indicated in the table footnotes and are not tested in production. Based on characterization, the minimum and maximum values refer to sample tests and represent the mean value plus or minus three times the standard deviation (mean3). 12.1.2 Typical Values Unless otherwise specified, typical data is based VDD = 5V (for the on TA = 25C, 4.5V VDD 5.5V voltage range). They are given only as design guidelines and are not tested. Typical ADC accuracy values are determined by characterization of a batch of samples from a standard diffusion lot over the full temperature range, where 95% of the devices have an error less than or equal to the value indicated (mean2). 12.1.3 Typical Curves Unless otherwise specified, all typical curves are given only as design guidelines and are not tested. 12.1.4 Loading Capacitor The loading conditions used for pin parameter measurement are shown in Figure 117. Figure 117. Pin Loading Conditions 12.1.5 Pin Input Voltage The input voltage measurement on a pin of the device is described in Figure 118. Figure 118. Pin input voltage
ST7 P IN
VIN
ST7 P IN
CL
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12.2 ABSOLUTE MAXIMUM RATINGS Stresses above those listed as "absolute maximum ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device under these condi12.2.1 Voltage Characteristics
Symbol VDD - VS S VPP - VSS VI N |VDDx| and |VSSx| |VSSA - VSSx| VESD(HBM) VESD(MM) Supply voltage Programming Voltage Input voltage on any pin1)2) Variations between different digital power pins Variations between digital and analog ground pins Electro-static discharge voltage (Human Body Model) Electro-static discharge voltage (Machine Model) Ratings
tions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.
Maximum value 6.5 13 VSS - 0.3 to VDD + 0.3 50 50
Unit V
mV
see Section 12.8.3 on page 233
12.2.2 Current Characteristics
Symbol I VDD IVSS IIO Ratings Total current into VDD power lines (source)
3)
Maximum value 150 25 50 - 25
Unit
Total current out of VSS ground lines (sink)3) Output current sunk by any standard I/O and control pin Output current sunk by any high sink I/O pin Output current source by any I/Os and control pin Injected current on VPP pin Injected current on RESET pin
mA 5 +5 5 25
IINJ(PIN)2)4)
Injected current on OSC1 and OSC2 pins Injected current on PB3 (on Flash devices) Injected current on any other pin5)
IINJ(PIN)2)
Total injected current (sum of all I/O and control pins)5)
12.2.3 Thermal Characteristics
Symbol TSTG TJ Ratings Storage temperature range Value -65 to +150 Unit C
Maximum junction temperature (see Section 13.2 "THERMAL CHARACTERISTICS")
Notes: 1. Directly connecting the RESET and I/O pins to VDD or VSS could damage the device if an unintentional internal reset is generated or an unexpected change of the I/O configuration occurs (for example, due to a corrupted program counter). To guarantee safe operation, this connection has to be done through a pull-up or pull-down resistor (typical: 4.7k for RESET, 10k for I/Os). Unused I/O pins must be tied in the same way to VDD or VSS according to their reset configuration. 2. IINJ(PIN) must never be exceeded. This is implicitly insured if VIN maximum is respected. If VIN maximum cannot be respected, the injection current must be limited externally to the IINJ(PIN) value. A positive injection is induced by VIN>VDD while a negative injection is induced by VIN < VSS. For true open-drain pads, there is no positive injection current, and the corresponding VIN maximum must always be respected 3. All power (VDD) and ground (VSS) lines must always be connected to the external supply. 4. Negative injection disturbs the analog performance of the device. See note in "10-BIT ADC CHARACTERISTICS" on page 245. 5. When several inputs are submitted to a current injection, the maximum IINJ(PIN) is the absolute sum of the positive and negative injected currents (instantaneous values). These results are based on characterization with IINJ(PIN) maximum current injection on four I/O port pins of the device.
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12.3 OPERATING CONDITIONS 12.3.1 General Operating Conditions
Symbol fCPU Parameter Internal clock frequency Extended Operating voltage VDD Standard Operating Voltage Operating Voltage for Flash Write/Erase VPP = 11.4 to 12.6V 1 Suffix Version 5 Suffix Version TA Ambient temperature range 6 Suffix Version 7 Suffix Version 3 Suffix Version -40 No Flash Write/Erase. Analog parameters not guaranteed. Conditions Min 0 3.8 4.5 4.5 0 -10 M ax 8 4.5 5.5 5.5 70 85 85 105 125 C Unit M Hz V
Figure 119. fCPU Maximum vs VDD
fCPU [MHz]
FUNCTIONALITY GUARANTEED IN THIS AREA UNLESS OTHERWISE SPECIFIED IN THE TABLES OF PARAMETRIC DATA FUNCTIONALITY GUARANTEED IN THIS AREA
8 FUNCTIONALITY NOT GUARANTEED IN THIS AREA
6
4 2 1 0 3.5 3.8 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE [V]
Note: It is mandatory to connect all available VDD and VDDA pins to the supply voltage and all VSS and VSSA pins to ground.
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12.3.2 Operating Conditions with Low Voltage Detector (LVD) Subject to general operating conditions for TA.
Symbol VIT+(LVD) VIT-(LVD) Vhys(LVD) VtPOR tg(VDD) Parameter Reset release threshold (VDD rise) Reset generation threshold (VDD fall) LVD voltage threshold hysteresis1) VDD rise time rate1) VDD glitches filtered (not detected) by Measured at VIT-(LVD) LVD1) VIT+(LVD)-VIT-(LVD) Conditions Min 4.0 1 ) 3.8 150 6 100 40 Typ 4.2 4.0 200 Max 4.5 4.251) 250 Unit V mV s/V ms/V ns
Notes: 1. Data based on characterization results, not tested in production.
12.3.3 Auxiliary Voltage Detector (AVD) Thresholds Subject to general operating conditions for TA.
Symbol V IT+( AV D) VIT-(AVD) Vhys(AVD) VITParameter 10 AVDF flag toggle threshold (VDD rise) 01 AVDF flag toggle threshold (VDD fall) AVD voltage threshold hysteresis Voltage drop between AVD flag set and LVD reset activated VIT+(AVD)-VIT-(AVD) VIT-(AVD)-VIT-(LVD) Conditions Min 4.41) 4.2 Typ 4.6 4.4 250 450 mV Max 4.9 V 4.651 ) Unit
1. Data based on characterization results, not tested in production.
Figure 120. LVD Startup Behavior
5V VIT+ LVD RESET
VD
D
2V Reset state not defined in this area t
Note: When the LVD is enabled, the MCU reaches its authorized operating voltage from a reset state. However, in some devices, the reset signal may be undefined until VDD is approximately 2V. As a consequence, the I/Os may toggle when VDD is below this voltage. Because Flash write access is impossible below this voltage, the Flash memory contents will not be corrupted.
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12.4 SUPPLY CURRENT CHARACTERISTICS The following current consumption specified for the ST7 functional operating modes over temperature range does not take into account the clock source current consumption. To get the total deSymbol Parameter
vice consumption, the two current values must be added (except for HALT mode for which the clock is stopped).
Flash Devices ROM Devices Typ 1) 1.8 3.2 6 10 0.5 0.6 0.85 1.25 1 1.8 3.4 6.4 0.4 0.5 0.6 0.8 <1 0.5 Max2 ) 3 5 8 15 2.7 3 3.6 4 3 4 5 7 1.2 1.3 1.8 2 10 50 1.2 30 70 Typ 1 1.1 2.2 4.4 8.9 0.1 0.2 0.4 0.8 0.7 1.4 2.9 5.7 0.07 0.14 0.28 0.56 <1 0.18 25 Max2) 2 3.5 6 12 0.2 0.4 0.8 1.5 3 4 5 7 0.12 0.25 0.5 1 10 50 0.25 30 70 A mA A
Conditions fOSC = 2 MHz, fCPU = 1 MHz fOSC = 4 MHz, fCPU = 2 MHz fOSC = 8 MHz, fCPU = 4 MHz fOSC = 16 MHz, fCPU = 8 MHz
3)
Unit
Supply current in RUN mode3)
Supply current in SLOW mode
fOSC = 2 MHz, fCPU = 62.5kHz fOSC = 4 MHz, fCPU = 125 kHz fOSC = 8 MHz, fCPU = 250 kHz fOSC = 16 MHz, fCPU = 500 kHz fOSC = 2 MHz, fCPU = 1 MHz fOSC = 4 MHz, fCPU = 2 MHz fOSC = 8 MHz, fCPU = 4 MHz fOSC = 16 MHz, fCPU = 8 MHz fOSC = 2 MHz, fCPU = 62.5 kHz fOSC = 4 MHz, fCPU = 125 kHz fOSC = 8 MHz, fCPU = 250 kHz fOSC = 16 MHz, fCPU = 500 kHz VDD = 5.5V -40C TA +85C -40C TA +125C
mA
Supply current in WAIT mode3) I DD Supply current in SLOW WAIT mode2) Supply current in HALT mode4) Supply current in ACTIVE HALT mode4)5) Supply current in AWUFH mode4)5)
VDD = 5.5V
-40C TA +85C -40C TA +125C
25
Notes: 1. Typical data are based on TA = 25C, VDD = 5V (4.5V VDD 5.5V range). 2. Data based on characterization results, tested in production at VDD max., fCPU max. and TA max. 3. Measurements are done in the following conditions: - Program executed from Flash, CPU running with Flash (for flash devices). - All I/O pins in input mode with a static value at VDD or VSS (no load) - All peripherals in reset state. - Clock input (OSC1) driven by external square wave. - In SLOW and SLOW WAIT mode, fCPU is based on fOSC divided by 32. To obtain the total current consumption of the device, add the clock source (Section 12.5.3) and the peripheral power consumption (Section 12.4.2). 4. All I/O pins in input mode with a static value at VDD or VSS (no load). Data based on characterization results, tested in production at VDD max., fCPU max. and TA max. 5. This consumption refers to the Halt period only and not the associated run period which is software dependent.
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SUPPLY CURRENT CHARACTERISTICS (Cont'd) 12.4.1 Supply and Clock Managers The previous current consumption specified for the ST7 functional operating modes over temperature range does not take into account the clock
Symbol IDD(RES) IDD(PLL) IDD(LVD) Param e ter Supply current of resonator oscillator PLL supply current LVD supply current
2)3)
source current consumption. To obtain the total device consumption, the two current values must be added (except for HALT mode).
Conditions Typ 360 150 300 Max1 ) Unit A
See Section 12.5.3 on page 227 VDD = 5V HALT mode, VDD = 5V
Notes: 1. Data based on characterization results, not tested in production. 2. Data based on characterization results done with the external components specified in Section 12.5.3, not tested in production. 3. As the oscillator is based on a current source, the consumption does not depend on the voltage.
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12.4.2 On-Chip Peripherals TA = 25C, fCPU = 8 MHz.
Symbol IDD(TIM) I DD(TIM8) IDD(ART) IDD(SPI) IDD(SCI) IDD(ADC) IDD(CAN) Parameter 16-bit Timer supply current1) 8-bit Timer supply current 1) ART PWM supply current2) SPI supply current3) SCI supply current4) ADC supply current when converting CAN supply current 6)
5)
Conditions
Typ 50 75
Unit
VDD = 5.0V 400 800
A
Notes: 1. Data based on a differential IDD measurement between reset configuration (timer counter running at fCPU/4) and timer counter stopped (only TIMD bit set). Data valid for one timer. 2. Data based on a differential IDD measurement between reset configuration (timer stopped) and timer counter enabled (only TCE bit set). 3. Data based on a differential IDD measurement between reset configuration (SPI disabled) and a permanent SPI master communication at maximum speed (data sent equal to 55h).This measurement includes the pad toggling consumption. 4. Data based on a differential IDD measurement between SCI low power state (SCID = 1) and a permanent SCI data transmit sequence. Data valid for one SCI. 5. Data based on a differential IDD measurement between reset configuration and continuous A/D conversions. 6. Data based on a differential IDD measurement between reset configuration (CAN disabled) and a permanent CAN data transmit sequence with RX and TX connected together. This measurement include the pad toggling consumption.
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12.5 CLOCK AND TIMING CHARACTERISTICS Subject to general operating conditions for VDD, fOSC, and TA. 12.5.1 General Timings
Symbol t c(INS T ) tv(IT) Parameter Instruction cycle time Interrupt reaction time tv(IT) = tc(INST) + 10
2)
Conditions fCPU = 8 MHz fCPU = 8 MHz
Min 2 250 10 1.25
Typ1) 3 375
Max 12 1500 22 2.75
Unit tCPU ns tCPU s
12.5.2 External Clock Source
Symbol VOSC1H VOSC1L tw(OSC1H) tw(OSC1L) tr(OSC1) tf(OSC1) IL Parameter OSC1 input pin high level voltage OSC1 input pin low level voltage OSC1 high or low time3) OSC1 rise or fall time3) OSCx Input leakage current VSS VIN VDD see Figure 121 Conditions Min 0.7 x V D D VS S 25 ns 5 1 A Typ M ax VDD 0.3 x V D D Unit V
Figure 121. Typical Application with an External Clock Source
90% VOSC1H 10%
VOSC1L tr(OSC1) tf(OSC1) tw(OSC1H) tw(OSC1L)
OSC2
Not connected internally fOSC
EXTERNAL CLOCK SOURCE
OSC1
IL ST72XXX
Notes: 1. Data based on typical application software. 2. Time measured between interrupt event and interrupt vector fetch. tc(INST) is the number of tCPU cycles needed to finish the current instruction execution. 3. Data based on design simulation and/or technology characteristics, not tested in production.
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CLOCK AND TIMING CHARACTERISTICS (Cont'd) 12.5.3 Crystal and Ceramic Resonator Oscillators The ST7 internal clock can be supplied with four different Crystal/Ceramic resonator oscillators. All the information given in this paragraph is based on characterization results with specified typical external components. In the application, the resonator and the load capacitors have to be placed as
Symbol fOSC RF CL1 CL2 Parameter Oscillator Frequency3) Feedback resistor Recommended load capacitance versus equivalent serial resistance of the crystal or ceramic resonator (RS) Param e ter OSC2 driving current
close as possible to the oscillator pins in order to minimize output distortion and start-up stabilization time. Refer to the crystal/ceramic resonator manufacturer for more details (frequency, package, accuracy...). 1)2)
Conditions Min 1 >2 >4 >8 20 22 22 18 15 Typ 80 160 310 610 M ax 2 4 8 16 40 56 46 33 33 Max 150 250 460 910 Unit MHz k pF
LP: Low power oscillator MP: Medium power oscillator MS: Medium speed oscillator HS: High speed oscillator RS = 200 RS = 200 RS = 200 RS = 100 LP oscillator MP oscillator MS oscillator HS oscillator
Symbol i2
Conditions VDD = 5V VI N = VS S LP oscillator MP oscillator MS oscillator HS oscillator
Unit A
Figure 122. Typical Application with a Crystal or Ceramic Resonator
WHEN RESONATOR WITH INTEGRATED CAPACITORS
i2
fOSC OSC1
CL1
RESONATOR CL2 OSC2
RF ST72XXX
Notes: 1. Resonator characteristics given by the crystal/ceramic resonator manufacturer. 2. tSU(OSC) is the typical oscillator start-up time measured between VDD = 2.8V and the fetch of the first instruction (with a quick VDD ramp-up from 0 to 5V (< 50s). 3. The oscillator selection can be optimized in terms of supply current using an high quality resonator with small RS value. Refer to crystal/ceramic resonator manufacturer for more details.
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CLOCK CHARACTERISTICS (Cont'd) 12.5.4 PLL Characteristics Operating conditions: VDD 3.8 to 5.5V @ TA 0 to 70C1) or VDD 4.5 to 5.5V @ TA -40 to 125C
Symbol VDD(PLL) fOSC fCPU/fCPU Parameter PLL Voltage Range PLL input frequency range PLL jitter1) fOSC = 4 MHz, VDD = 4.5 to 5.5V fOSC = 2 MHz, VDD = 4.5 to 5.5V Conditions TA = 0 to +70C TA = -40 to +125C Min 3.8 4.5 2 Note 2 Typ M ax 5.5 4 M Hz % Unit
Notes: 1. Data characterized but not tested. 2. Under characterization
Figure 123. PLL Jitter vs Signal Frequency1)
0.8 0.7 0.6 +/-Jitter (%) 0.5 0.4 0.3 0.2 0.1 0 2000 1000 500 250 125 Application Signal Frequency (KHz) PLL ON PLL OFF
The user must take the PLL jitter into account in the application (for example in serial communication or sampling of high frequency signals). The PLL jitter is a periodic effect, which is integrated over several CPU cycles. Therefore, the longer the period of the application signal, the less it is impacted by the PLL jitter. Figure 123 shows the PLL jitter integrated on application signals in the range 125 kHz to 2 MHz. At frequencies of less than 125 kHz, the jitter is negligible.
Notes: 1. Measurement conditions: fCPU = 4 MHz, TA = 25C
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CLOCK CHARACTERISTICS (Cont'd) 12.6 Auto Wakeup from Halt Oscillator (AWU)
Symbol fAWU tRCSRT Parameter AWU oscillator frequency1) AWU oscillator startup time Conditions Min 50 Typ 100 10 Max 250 Unit kHz s
1. Data based on characterization results, not tested in production.
Figure 124. AWU Oscillator Freq. @ TA 25C
200 150 100 50 Ta=25C
Freq(KHz)
4.4
5 Vdd
5.6
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12.7 MEMORY CHARACTERISTICS 12.7.1 RAM and Hardware Registers
Symbol VRM Param e ter Data retention mode
1)
Conditions HALT mode (or RESET)
Min 1.6
Typ
M ax
Unit V
12.7.2 FLASH Memory
DUAL VOLTAGE HDFLASH MEMORY Symbol Parameter fCPU VP P IPP tVPP tRET NRW TP R O G TERASE Operating frequency Programming voltage3) VPP current4)5) Internal VPP stabilization time Data retention Write erase cycles Programming or erasing temperature range TA = 85C TA = 105C TA = 125C TA = 25C 40 15 7 100 -40 25 85 Conditions Read mode Write / Erase mode 4.5V VDD 5.5V Read (VPP = 12V) Write / Erase Min2) 0 1 11.4 Typ Max2 ) 8 8 12.6 200 30 Unit MH z V A mA s years cycles C
104 )
Notes: 1. Minimum VDD supply voltage without losing data stored in RAM (in HALT mode or under RESET) or in hardware registers (only in HALT mode). Not tested in production. 2. Data based on characterization results, not tested in production. 3. VPP must be applied only during the programming or erasing operation and not permanently for reliability reasons. 4. Data based on simulation results, not tested in production. 5. In Write / erase mode the IDD supply current consumption is the same as in Run mode (see Section 12.2.2)
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12.8 EMC CHARACTERISTICS Susceptibility tests are performed on a sample basis during product characterization. 12.8.1 Functional EMS (Electro Magnetic Susceptibility) Based on a simple running application on the product (toggling two LEDs through I/O ports), the product is stressed by two electro magnetic events until a failure occurs (indicated by the LEDs). ESD: Electro-Static Discharge (positive and negative) is applied on all pins of the device until a functional disturbance occurs. This test conforms with the IEC 1000-4-2 standard. FTB: A Burst of Fast Transient voltage (positive and negative) is applied to VDD and VSS through a 100pF capacitor, until a functional disturbance occurs. This test conforms with the IEC 1000-44 standard. A device reset allows normal operations to be resumed. The test results are given in the table below based on the EMS levels and classes defined in application note AN1709. 12.8.1.1 Designing hardened software to avoid noise problems EMC characterization and optimization are performed at component level with a typical applicaSymbol Parameter
tion environment and simplified MCU software. It should be noted that good EMC performance is highly dependent on the user application and the software in particular. Therefore it is recommended that the user applies EMC software optimization and prequalification tests in relation with the EMC level requested for his application. Software recommendations: The software flowchart must include the management of runaway conditions such as: Corrupted program counter Unexpected reset Critical Data corruption (control registers...) Prequalification trials: Most of the common failures (unexpected reset and program counter corruption) can be reproduced by manually forcing a low state on the RESET pin or the Oscillator pins for 1 second. To complete these trials, ESD stress can be applied directly on the device, over the range of specification values. When unexpected behavior is detected, the software can be hardened to prevent unrecoverable errors occurring (see application note AN1015).
Conditions Level/ Class 3B 2B 3B 2B
VF E S D
LQFP64, VDD = 5V, TA = +25C, Voltage limits to be applied on any I/O pin to induce a fOSC = 8 MHz, conforms to IEC 1000-4-2 functional disturbance LQFP44, VDD = 5V, TA = +25C, fOSC = 8 MHz, conforms to IEC 1000-4-2 LQFP64, VDD = 5V, TA = +25C, Fast transient voltage burst limits to be applied fOSC = 8 MHz, conforms to IEC 1000-4-4 through 100pF on VDD and VDD pins to induce a funcLQFP44, VDD = 5V, TA = +25C, tional disturbance fOSC = 8 MHz, conforms to IEC 1000-4-4
V FFTB
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EMC CHARACTERISTICS (Cont'd) 12.8.2 Electro Magnetic Interference (EMI) Based on a simple application running on the product (toggling two LEDs through the I/O ports), the product is monitored in terms of emission. This
Symbol Parameter Conditions
emission test is in line with the norm SAE J 1752/ 3 which specifies the board and the loading of each pin.
Monitored Frequency Band 0.1 MHz to 30 MHz 30 MHz to 130 MHz 130 MHz to 1 GHz SAE EMI Level 0.1 MHz to 30 MHz 30 MHz to 130 MHz 130 MHz to 1 GHz SAE EMI Level 0.1 MHz to 30 MHz 30 MHz to 130 MHz 130 MHz to 1 GHz SAE EMI Level Max vs. [fOSC/fCPU] 8/4 MHz 10 12 8 2.5 31 32 11 3.0 10 15 -3 2.0 16/8 MHz 13 19 14 3 32 37 16 3.5 18 25 1 2.5 d B V d B V d B V
Unit
Flash devices: VDD = 5V, TA = +25C, LQFP44 package conforming to SAE J 1752/3 Flash devices: VDD = 5V, TA = +25C, Peak level1) LQFP64 package conforming to SAE J 1752/3 ROM devices: VDD = 5V, TA = +25C, LQFP64 package conforming to SAE J 1752/3 Notes: 1. Not tested in production.
SE M I
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EMC CHARACTERISTICS (Cont'd) 12.8.3 Absolute Maximum Ratings (Electrical Sensitivity) Based on two different tests (ESD and LU) using specific measurement methods, the product is stressed in order to determine its performance in terms of electrical sensitivity (see Table 39 and Table 40 below). For more details, refer to application note AN1181. 12.8.3.1 Electro-Static Discharge (ESD) Electro-Static Discharges (a positive then a negative pulse separated by 1 second) are applied to the pins of each sample according to each pin combination. The sample size depends on the Table 39. Absolute Maximum Ratings
Symbol VESD(MM) Ratings
number of supply pins in the device (3 parts*(n+1) supply pin). Two models can be simulated: Human Body Model and Machine Model. This test conforms to the JESD22-A114A/A115A standard. 12.8.3.2 Static Latch-Up LU: Two complementary static tests are required on 6 parts to assess the latch-up performance. A supply overvoltage (applied to each power supply pin) and a current injection (applied to each input, output and configurable I/ O pin) are performed on each sample. This test conforms to the EIA/JESD 78 IC latch-up standard.
Conditions
Maximum value1) 2000 200 750 on corner pins, 500 on others
Unit
VESD(HBM) Electro-static discharge voltage (Human Body Model) Electro-static discharge voltage (Machine Model) TA = +25C
V
VESD(CDM) Electro-static discharge voltage (Charge Device Model) Notes: 1. Data based on characterization results, not tested in production.
Table 40. Electrical Sensitivities
Symbol LU Parameter Static latch-up class Conditions T A = +125C conforming to JESD 78 Class II level A
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12.9 I/O PORT PIN CHARACTERISTICS 12.9.1 General Characteristics Subject to general operating conditions for VDD, fOSC, and TA unless otherwise specified.
Symbol VI L VIH Vhys VI L VIH Vhys IINJ(PIN) IINJ(PIN)3) I lkg IS RP U CI O tf(IO)out tr(IO)out t w(IT)in Parameter Input low level voltage1) CMOS ports 0 . 7 x VD D 1 0.8 TTL ports Flash devices ROM devices 2 400 0 +4 4 4 25 VS S VI N VDD
5)
Conditions
Min
Typ
Max 0.3 x VDD
Unit
Input high level voltage1) Schmitt trigger voltage hysteresis2) Input low level voltage1) Input high level voltage1) Schmitt trigger voltage hysteresis2) Injected Current on PB3
V
mV
Injected Current on any other I/O pin VDD = 5V Total injected current (sum of all I/O and control pins)7) Input leakage current4) Static current consumption I/O pin capacitance Output high to low level fall time Output low to high level rise time External interrupt pulse time7) CL = 50pF Between 10% and 90% 1 Weak pull-up equivalent resistor6)
mA
Input leakage current on robust pins See "10-BIT ADC CHARACTERISTICS" on page 245 1 200 50 90 5 25 250 Floating input mode VIN = VSS VDD = 5V A k pF ns t CPU
Notes: 1. Data based on characterization results, not tested in production. 2. Hysteresis voltage between Schmitt trigger switching levels. Based on characterization results, not tested. 3. When the current limitation is not possible, the VIN absolute maximum rating must be respected, otherwise refer to IINJ(PIN) specification. A positive injection is induced by VIN > VDD while a negative injection is induced by VIN < VSS. Refer to Section 12.2 on page 220 for more details. 4. Leakage could be higher than max. if negative current is injected on adjacent pins. 5. Configuration not recommended, all unused pins must be kept at a fixed voltage: Using the output mode of the I/O, for example, or an external pull-up or pull-down resistor (see Figure 125). Data based on design simulation and/or technology characteristics, not tested in production. 6. The RPU pull-up equivalent resistor is based on a resistive transistor (corresponding IPU current characteristics described in Figure 126). 7. To generate an external interrupt, a minimum pulse width must be applied on an I/O port pin configured as an external interrupt source.
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I/O PORT PIN CHARACTERISTICS (Cont'd) Figure 125. Connecting Unused I/O Pins Figure 127. IPU vs VDD with VIN = VSS
VDD 10k
ST72XXX
100
UNUSED I/O PORT
Ipu (A)
80 60 40 20 0 3.5
Ta=-45C Ta=25C Ta=130C
10k
UNUSED I/O PORT
4
ST72XXX
4.5 Vdd
5
5.5
Figure 126. RPU vs VDD with VIN = VSS
200
150 Rpu (Ko)
Ta=-45C Ta=25C Ta=130C
100
50
0 3.5 4 4.5 Vdd 5 5.5
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I/O PORT PIN CHARACTERISTICS (Cont'd) 12.9.2 Output Driving Current Subject to general operating conditions for VDD, fOSC, and TA unless otherwise specified.
Symbol Parameter Output low level voltage for a standard I/O pin when eight pins are sunk at same time (see Figure 128) VDD= 5 V Output low level voltage for a high sink I/O pin when four pins are sunk at same time (see Figure 129 and Figure 132) Output high level voltage for an I/O pin when four pins are sourced at same time (see Figure 130 and Figure 133) Conditions IIO=+5mA IIO=+2mA IIO=+20mA, TA85C T A 85C IIO=+8mA IIO=-5mA, TA85C VDD-1.4 TA85C VDD-1.6 IIO=-2mA VDD-0.7 Min M ax 1.2 0.5 1.3 1.5 0.6 Unit
VOL1)
V
VOH2)
Figure 128. Typical VOL at VDD = 5V (Standard)
0.8 0.7 -45C 0.6 Voh(V) 0.5 0.4 0.3 25C
Figure 130. Typical VOH at VDD = 5V
4.9 4.8 4.7 4.6 Voh(V) 4.5 4.4 4.3
-45C 25C 130C
130C
0.2 0.1 2 Iio(mA) 5
4.2 4.1 -2
-5 Iio(mA)
Figure 129. Typical VOL at VDD = 5V (High-sink)
0.8 0.7 0.6 0.5 Vol (V) 0.4 0.3 0.2 0.1 0 2 5 Iol (mA) 8 20
-45C 25C 130C
Notes: 1. The IIO current sunk must always respect the absolute maximum rating specified in Section 12.2.2 and the sum of IIO (I/O ports and control pins) must not exceed IVSS. 2. The IIO current sourced must always respect the absolute maximum rating specified in Section 12.2.2 and the sum of IIO (I/O ports and control pins) must not exceed IVDD. True open drain I/O pins does not have VOH.
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I/O PORT PIN CHARACTERISTICS (Cont'd) Figure 131. Typical VOL vs VDD (Standard I/Os)
1.1 1 0.9 Vol(V) Iio=5mA 0.8 0.7 0.6 0.5 0.4 0.3 3 4 Vdd(V) 5 6 0.15 0.1 3 4 Vdd(V) 5 6 -45C 25C Vol(V) Iio=2mA 130C 0.3 0.4 -45C 25C 130C
0.35
0.25 0.2
Figure 132. Typical VOL vs VDD (High-sink I/Os)
0.4 -45C 0.35 0.3 25C Vol(V) Iio=20mA 130C 1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.1 3 4 Vdd(V) 5 6 0.3 3 4 Vdd(V) 5 6 -45C 25C 130C
Vol(V) Iio=8mA
0.25 0.2
0.15
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I/O PORT PIN CHARACTERISTICS (Cont'd) Figure 133. Typical VOH vs VDD
6 6 -45C 5 Voh(V) Iio=5mA 25C 130C 4
5 Voh(V) Iio=2mA
4
-45C 25C 130C
3
3
2
2 3 4 Vdd(V) 5 6
1 3 4 Vdd(V) 5 6
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12.10 CONTROL PIN CHARACTERISTICS 12.10.1 Asynchronous RESET Pin Subject to general operating conditions for VDD, fOSC, and TA unless otherwise specified.
Symbol VI L VIH Vhys VO L RO N th(RSTL)in tg(RSTL)in Param e ter Input low level voltage1) 0.7 x VDD VDD = 5V VDD = 5V VIN = VSS Internal reset source 2.5 200 IIO = +5mA IIO = +2mA 20 1.5 0.68 0.28 40 30 0.95 0.45 80 k s ns V Input high level voltage1) Schmitt trigger voltage hysteresis2) Output low level voltage3) Weak pull-up equivalent resistor4) External reset pulse hold time5) Filtered glitch duration6) Conditions Min Typ Max 0.3 x VDD Unit
tw(RSTL)out Generated reset pulse duration
Notes: 1. Data based on characterization results, not tested in production. 2. Hysteresis voltage between Schmitt trigger switching levels. 3. The IIO current sunk must always respect the absolute maximum rating specified in Section 12.2.2 and the sum of IIO (I/O ports and control pins) must not exceed IVSS. 4. To guarantee the reset of the device, a minimum pulse has to be applied to the RESET pin. All short pulses applied on the RESET pin with a duration below th(RSTL)in can be ignored. 5. The reset network (the resistor and two capacitors) protects the device against parasitic resets, especially in noisy environments. 6. Data guaranteed by design, not tested in production.
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CONTROL PIN CHARACTERISTICS (Cont'd) Figure 134. RESET Pin Protection When LVD Is Enabled1)2)
V DD
ST72XXX
Recommended
EXTERNAL RESET
0.01F
O p tional (note 2.2)
RON
Filter
INTERNAL RESET
1M
PULSE GENERATOR
WATCHDOG LVD RESET
Figure 135. RESET Pin Protection When LVD Is Disabled1)
VDD
VDD ST72XXX
USER EXTERNAL RESET CIRCUIT 0.01F
4.7k
R ON
Filter
INTERNAL RESET
PULSE GENERATOR
WATCHDOG
Required
Note 1: 1.1 The reset network protects the device against parasitic resets. 1.2 The output of the external reset circuit must have an open-drain output to drive the ST7 reset pad. Otherwise the device can be damaged when the ST7 generates an internal reset (LVD or watchdog). 1.3 Whatever the reset source is (internal or external), the user must ensure that the level on the RESET pin can go below the VIL max. level specified in Section 12.10.1. Otherwise the reset will not be taken into account internally. 1.4 Because the reset circuit is designed to allow the internal RESET to be output in the RESET pin, the user must ensure that the current sunk on the RESET pin (by an external pull-up for example) is less than the absolute maximum value specified for IINJ(RESET) in Section 12.2.2 on page 220. Note 2: 2.1 When the LVD is enabled, it is mandatory not to connect a pull-up resistor. A 10nF pull-down capacitor is recommended to filter noise on the reset line. 2.2. In case a capacitive power supply is used, it is recommended to connect a1MW pull-down resistor to the RESET pin to discharge any residual voltage induced by this capacitive power supply (this will add 5A to the power consumption of the MCU). 2.3. Tips when using the LVD: 1. Check that all recommendations related to reset circuit have been applied (see notes above) 2. Check that the power supply is properly decoupled (100nF + 10F close to the MCU). Refer to AN1709. If this cannot be done, it is recommended to put a 100nF + 1MW pull-down on the RESET pin. 3. The capacitors connected on the RESET pin and also the power supply are key to avoiding any start-up marginality. In most cases, steps 1 and 2 above are sufficient for a robust solution. Otherwise: Replace 10nF pull-down on the RESET pin with a 5F to 20F capacitor.
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CONTROL PIN CHARACTERISTICS (Cont'd) Figure 136. RESET RPU vs VDD
100 Rpu (kOhm) 80 60 40 20 0 3.5 4 4.5 Vdd 5 5.5 Ta=-45C Ta=25C Ta=130C
12.10.2 ICCSEL/VPP Pin Subject to general operating conditions for VDD, fOSC, and TA unless otherwise specified.
Symbol VI L VIH IL Param e ter Input low level voltage1) V I N = VS S Input high level voltage1) Input leakage current Conditions Min VSS V D D -0. 1 Max 0.2 12.6 1 Unit
V
A
Figure 137. Two Typical Applications with ICCSEL/VPP Pin2)
ICCSEL/VPP VPP 10k
PROGRAMMING TOOL
ST72XXX
ST72XXX
Notes: 1. Data based on design simulation and/or technology characteristics, not tested in production. 2. When ICC mode is not required by the application ICCSEL/VPP pin must be tied to VSS.
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12.11 TIMER PERIPHERAL CHARACTERISTICS Subject to general operating conditions for VDD, fOSC, and TA unless otherwise specified. 12.11.1 8-Bit PWM-ART Autoreload Timer
Symbol Parameter Conditions Min 1 fCPU = 8 MHz 125 0 fCPU/2 8 VDD = 5V, Res = 8-bits fCPU = 8 MHz 1 0.125 20 128 16 Typ Max Unit t CPU ns M Hz bit mV t CPU s
Refer to I/O port characteristics for more details on the input/output alternate function characteristics (output compare, input capture, external clock, PWM output...).
tres(PWM) PWM resolution time fEXT fPWM Res P W M VOS t COUNTER ART external clock frequency PWM repetition rate PWM resolution PWM/DAC output step voltage Timer clock period when internal clock is selected
12.11.2 8-Bit Timer
Symbol Parameter Conditions Min 1 2 fCPU = 8 MHz 250 0 fCPU/4 8 fCPU = 8 MHz 2 0.250 8000 1000 Typ Max Unit t CPU ns M Hz bit t CPU s
tw(ICAP)in Input capture pulse time tres(PWM) PWM resolution time fPWM Res P W M PWM repetition rate PWM resolution
tCOUNTER Timer clock period
12.11.3 16-Bit Timer
Symbol Parameter Conditions Min 1 2 fCPU = 8 MHz 250 0 fCPU/4 16 fCPU = 8 MHz 2 0.250 8 1 Typ Max Unit t CPU ns M Hz bit t CPU s
tw(ICAP)in Input capture pulse time tres(PWM) PWM resolution time fEXT fPWM Res P W M t COUNTER Timer external clock frequency PWM repetition rate PWM resolution Timer clock period when internal clock is selected
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12.12 COMMUNICATION INTERFACE CHARACTERISTICS 12.12.1 SPI - Serial Peripheral Interface Subject to general operating conditions for VDD, fOSC, and TA unless otherwise specified.
Symbol Parameter
Refer to I/O port characteristics for more details on the input/output alternate function characteristics (SS, SCK, MOSI, MISO).
Min Max Unit
Conditions Master, fCPU = 8 MHz Slave, fCPU = 8 MHz
fSCK = 1 / tc(SCK) SPI clock frequency tr(SCK) tf(SCK) tsu(SS)1) th(SS) tw(SCKH)1) tw(SCKL)1) tsu(MI)1) tsu(SI)1) th(MI)1) th(SI)1) ta(SO)1) tdis(SO)1) tv(SO)1) th(SO)1) tv(MO)1) th(MO)1)
1)
fCPU / 128 = 0.0625 fCPU / 4 = 2 MHz 0 f CPU / 2 = 4 See I/O port pin description
SPI clock rise and fall time SS setup time4) SS hold time SCK high and low time Data input setup time Data input hold time Data output access time Data output disable time Data output valid time Data output hold time Data output valid time Data output hold time Slave Master Slave Master Slave Master Slave Slave Slave (after enable edge) Master (after enable edge)
(4 x TCPU) + 50 120 100 90
100 ns 0 120 240 90 0 120 0
Figure 138. SPI Slave Timing Diagram with CPHA = 03)
SS INPUT tsu(SS) SCK INPUT CPHA = 0 CPOL = 0 CPHA = 0 CPOL = 1 ta(SO) MISO OUTPUT tw(SCKH) tw(SCKL) tv(SO) th(SO) tr(SCK) tf(SCK)
LSB OUT
tc(SCK)
th(SS)
tdis(SO)
See note 2
See note 2
MSB OUT
BIT6 OUT
tsu(SI)
th(SI)
MOSI INPUT
MSB IN
BIT1 IN
LSB IN
Notes: 1. Data based on design simulation and/or characterization results, not tested in production. 2. When no communication is on-going the data output line of the SPI (MOSI in master mode, MISO in slave mode) has its alternate function capability released. In this case, the pin status depends on the I/O port configuration. 3. Measurement points are done at CMOS levels: 0.3 x VDD and 0.7 x VDD. 4. Depends on fCPU. For example, if fCPU = 8 MHz, then TCPU = 1 / fCPU = 125ns and tsu(SS) = 550ns.
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COMMUNICATION INTERFACE CHARACTERISTICS (Cont'd) Figure 139. SPI Slave Timing Diagram with CPHA = 11)
SS INPUT tsu(SS) SCK INPUT CPHA = 0 CPOL = 0 CPHA = 0 CPOL = 1 ta(SO) tw(SCKH) tw(SCKL) tv(SO) th(SO) tr(SCK) tf(SCK)
LSB OUT
tc(SCK)
th(SS)
tdis(SO)
MISO OUTPUT
See note 2
Hz
MSB OUT
BIT6 OUT
See note 2
tsu(SI)
th(SI)
MOSI INPUT
MSB IN
BIT1 IN
LSB IN
Figure 140. SPI Master Timing Diagram1)
SS INPUT tc(SCK) CPHA = 0 CPOL = 0 SCK INPUT CPHA = 0 CPOL = 1 CPHA = 1 CPOL = 0 CPHA = 1 CPOL = 1 tw(SCKH) tw(SCKL) tsu(MI) MISO INPUT tv(MO) th(MI) tr(SCK) tf(SCK)
MSB IN
BIT6 IN
LSB IN
th(MO)
MOSI OUTPUT
See note 2
MSB OUT
BIT6 OUT
LSB OUT
See note 2
Notes: 1. Measurement points are done at CMOS levels: 0.3 x VDD and 0.7 x VDD. 2. When no communication is on-going the data output line of the SPI (MOSI in master mode, MISO in slave mode) has its alternate function capability released. In this case, the pin status depends on the I/O port configuration.
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COMMUNICATIONS INTERFACE CHARACTERISTICS (Cont'd) 12.12.2 CAN - Controller Area Network Interface Subject to general operating condition for VDD, fOSC, and TA unless otherwise specified. Refer to I/O port characteristics for more details on
Symbol tp(RX:TX) Parameter CAN controller propagation time
1)
the input/output alternate function characteristics (CANTX and CANRX).
Min Typ Max 60 Unit ns
Conditions
1. Data based on characterization results, not tested in production.
12.13 10-BIT ADC CHARACTERISTICS Subject to general operating conditions for VDD, fCPU, and TA unless otherwise specified.
Symbol fADC VAIN RAIN CAIN fAIN Ilkg CADC t CONV IADC Param e ter ADC clock frequency Conversion voltage range2) External input impedance External capacitor on analog input Variation frequency of analog input signal Negative input leakage current on ro- V < V | I | < 400A on IN SS, IN bust analog pins (refer to Table 2 on adjacent robust analog pin page 8) Internal sample and hold capacitor Conversion time Analog part Digital part fADC = 4 MHz Sunk on VDDA2) Sunk on VDD 5 6 3.5 14 3.6 0.2 Conditions Min1) 0.4 VSSA Typ Max 1 ) 4 VDDA see Figure 141 and Figure 142 6 Unit MHz V k pF Hz A pF s 1/fADC mA
Notes: 1. Data based on characterization results, not tested in production. 2. When VDDA and VSSA pins are not available on the pinout, the ADC refers to VDD and VSS.
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ADC CHARACTERISTICS (Cont'd) Figure 141. RAIN Max vs fADC with CAIN = 0pF1)2)
45 40
Figure 142. Recommended CAIN/RAIN Values3)
1000
Cain 10 nF
Max. R AIN (Kohm)
35 30 25 20 15 10 5 0 0 10 30
4 MHz
Max. R AIN (Kohm)
2 MHz 1 MHz
100
Cain 22 nF Cain 47 nF
10
1
0.1
70
0.01
0.1
1
10
CPARASI TI C (pF)
fAI N(K Hz )
Figure 143. Typical Application with ADC
VDD VT 0.6V RAIN VAIN C AIN VT 0.6V IL 1A AINx
ST72XXX
2k(max)
10-Bit A/D Conversion CADC 6pF
Notes: 1. CPARASITIC represents the capacitance of the PCB (dependent on soldering and PCB layout quality) plus the pad capacitance (3pF). A high CPARASITIC value will downgrade conversion accuracy. To remedy this, fADC should be reduced. 2. Any added external serial resistor will downgrade the ADC accuracy (especially for resistance greater than 10k). Data based on characterization results, not tested in production. 3. This graph shows that depending on the input signal variation (fAIN), CAIN can be increased for stabilization time and reduced to allow the use of a larger serial resistor (RAIN). It is valid for all fADC frequencies 4 MHz.
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ADC CHARACTERISTICS (Cont'd) 12.13.0.1 Analog Power Supply and Reference Pins Depending on the MCU pin count, the package may feature separate VDDA and VSSA analog power supply pins. These pins supply power to the A/D converter cell and function as the high and low reference voltages for the conversion. In smaller packages VDDA and VSSA pins are not available and the analog supply and reference pads are internally bonded to the VDD and VSS pins. Separation of the digital and analog power pins allow board designers to improve A/D performance. Conversion accuracy can be impacted by voltage drops and noise in the event of heavily loaded or badly decoupled power supply lines (see Section 12.13.0.2 "General PCB Design Guidelines"). 12.13.0.2 General PCB Design Guidelines To obtain best results, some general design and layout rules should be followed when designing the application PCB to shield the noise-sensitive, analog physical interface from noise-generating CMOS logic signals. Use separate digital and analog planes. The analog ground plane should be connected to the digital ground plane via a single point on the PCB. Figure 144. Power Supply Filtering
ST72XXX 1 to 10F
ST7 DIGITAL NOISE FILTERING
Filter power to the analog power planes. It is recommended to connect capacitors, with good high frequency characteristics, between the power and ground lines, placing 0.1F and optionally, if needed 10pF capacitors as close as possible to the ST7 power supply pins and a 1 to 10F capacitor close to the power source (see Figure 144). The analog and digital power supplies should be connected in a star network. Do not use a resistor, as VDDA is used as a reference voltage by the A/D converter and any resistance would cause a voltage drop and a loss of accuracy. Properly place components and route the signal traces on the PCB to shield the analog inputs. Analog signals paths should run over the analog ground plane and be as short as possible. Isolate analog signals from digital signals that may switch while the analog inputs are being sampled by the A/D converter. Do not toggle digital outputs on the same I/O port as the A/D input being converted. 12.13.0.3 Software Filtering of Spurious Conversion Results For EMC performance reasons, it is recommended to filter A/D conversion outliers using software filtering techniques.
0.1F
V SS
VDD
VDD
POWER SUPPLY SOURCE EXTERNAL NOISE FILTERING
0.1F
VDDA
VSSA
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ADC CHARACTERISTICS (Cont'd) ADC Accuracy with fCPU = 8 MHz, fADC = 4 MHz RAIN < 10k, VDD = 5V
Symbol |ET| |EO| |EG| |ED| |EL| Offset error1) Gain Error
1)
Parameter Total unadjusted error1)
Conditions
Typ 3.2 1 0.7 1.5 1.2
M ax 5 4 2.3 3.6
Unit
LS B
Differential linearity error1) Integral linearity error1)
Figure 145. ADC Accuracy Characteristics
Digital Result ADCDR 1023 1022 1021 1LSB IDEAL V V DDA SSA = ----------------------------------------
EG
(1) Example of an actual transfer curve (2) The ideal transfer curve (3) End point correlation line
1024
(2) ET 7 6 5 4 3 2 1 0 1 V SSA 2 3 4 1 LSBIDEAL EO EL ED (3) (1)
ET=Total Unadjusted Error: maximum deviation between the actual and the ideal transfer curves. EO=Offset Error: deviation between the first actual transition and the first ideal one. EG=Gain Error: deviation between the last ideal transition and the last actual one. ED=Differential Linearity Error: maximum deviation between actual steps and the ideal one. EL=Integral Linearity Error: maximum deviation between any actual transition and the end point correlation line.
Vin (LSBIDEAL) 5 6 7 1021 1022 1023 1024 VDDA
Notes: 1. Data based on characterization results, not tested in production. ADC Accuracy vs. Negative Injection Current: Injecting negative current on any of the standard (non-robust) analog input pins should be avoided as this significantly reduces the accuracy of the conversion being performed on another analog input. It is recommended to add a Schottky diode (pin to ground) to standard analog pins which may potentially inject negative current. The effect of negative injection current on robust pins is specified in Section 12.9. Any positive injection current within the limits specified for IINJ(PIN) and IINJ(PIN) in Section 12.9 does not affect the ADC accuracy.
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13 PACKAGE CHARACTERISTICS
13.1 PACKAGE MECHANICAL DATA Figure 146. 64-Pin Low Profile Quad Flat Package (14x14)
D D1 A1 A A2
Dim. A A1 A2
mm Min 0.05 1.35 0.30 0.09 16.00 14.00 16.00 14.00 0.80 0 0.45 3.5 0.60 1.00 64 7 0 1.40 0.37 Typ Max 1.60 0.15 0.0020 Min
inches1) Typ Max 0.0630 0.0059
1.45 0.0531 0.0551 0.0571 0.45 0.0118 0.0146 0.0177 0.20 0.0035 0.6299 0.5512 0.6299 0.5512 0.0315 3.5 0.0394 Number of Pins 7 0.75 0.0177 0.0236 0.0295 0.0079
b
b c D
e E1 E
D1 E E1 e L
L L1 c h
L1 N
Note 1. Values in inches are converted from mm and rounded to 4 decimal digits.
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Figure 147. 64-Pin Low Profile Quad Flat Package (10 x10)
inches1) Max 1.60 0.05 1.35 0.17 0.09 12.00 10.00 12.00 10.00 0.50 0 0.45 3.5 0.60 1.00 64 7 0 1.40 0.22 0.15 0.0020 Min Typ Max 0.0630 0.0059
Dim.
D D1 A1 A A2
mm Min Typ
A A1 A2 b
1.45 0.0531 0.0551 0.0571 0.27 0.0067 0.0087 0.0106 0.20 0.0035 0.4724 0.3937 0.4724 0.3937 0.0197 3.5 0.0394 Number of Pins 7 0.75 0.0177 0.0236 0.0295 0.0079
b
c D D1
E1
E e
E E1 e
c
L L1 N
L1
L
Note 1. Values in inches are converted from mm and rounded to 4 decimal digits.
Figure 148. 44-Pin Low Profile Quad Flat Package (10x10)
Dim. mm Min Typ Max 1.60 0.05 1.35 0.30 0.09 12.00 10.00 12.00 10.00 0.80 0 0.45 3.5 0.60 1.00 7 0 1.40 0.37 0.15 0.0020 Min inches1) Typ Max 0.0630 0.0059
D D1 A1 b
A A2
A A1 A2 b C D D1
1.45 0.0531 0.0551 0.0571 0.45 0.0118 0.0146 0.0177 0.20 0.0035 0.4724 0.3937 0.4724 0.3937 0.0315 3.5 0.0394 Number of Pins 7 0.75 0.0177 0.0236 0.0295 0.0079
E1 E
e
E E1 e L
L1 L h
c
L1
N 44 Note 1. Values in inches are converted from mm and rounded to 4 decimal digits.
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Figure 149. 32-Pin Low Profile Quad Flat Package (7x7)
Dim.
A A2 A1
mm Min Typ Max 1.60 0.05 1.35 0.30 0.09 9.00 7.00 9.00 7.00 0.80 0 0.45 3.5 0.60 1.00 7 0 1.40 0.37 0.15 0.0020 Min
inches1) Typ Max 0.0630 0.0059
D D1
A A1 A2 b C D D1 E E1
c
1.45 0.0531 0.0551 0.0571 0.45 0.0118 0.0146 0.0177 0.20 0.0035 0.3543 0.2756 0.3543 0.2756 0.0315 3.5 0.0394 Number of Pins 7 0.75 0.0177 0.0236 0.0295 0.0079
e E1 E
b
L1 L h
e L L1
N 32 Note 1. Values in inches are converted from mm and rounded to 4 decimal digits.
13.2 THERMAL CHARACTERISTICS
Symbol
Ratings Package thermal resistance (junction to ambient) LQFP64 LQFP44 LQFP32 Power dissipation1) Maximum junction temperature
2)
Value 60 52 70 500 150
Unit
RthJA PD TJmax
C/W
mW C
Notes: 1. The maximum power dissipation is obtained from the formula PD = (TJ - TA) / RthJA. The power dissipation of an application can be defined by the user with the formula: PD = PINT + PPORT where PINT is the chip internal power (IDD x VDD) and PPORT is the port power dissipation depending on the ports used in the application. 2. The maximum chip-junction temperature is based on technology characteristics.
13.3 SOLDERING AND GLUEABILITY INFORMATION In order to meet environmental requirements, ST offers these devices in ECOPACK packages. These packages have a lead-free second level interconnect. The category of second level interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an ST trademark. ECOPACK specifications are available at www.st.com.
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14 DEVICE CONFIGURATION AND ORDERING INFORMATION
Each device is available for production in user programmable versions (FLASH) as well as in factory coded versions (ROM/FASTROM). ST72561 devices are ROM versions. ST72P561 devices are Factory Advanced Service Technique ROM (FASTROM) versions: They are factory-programmed HDFlash devices. ST72F561 FLASH devices are shipped to customers with a default content (FFh), while ROM factory coded parts contain the code supplied by the customer. This implies that FLASH devices have to be configured by the customer using the Option Bytes while the ROM devices are factory-configured. 14.1 FLASH OPTION BYTES The option bytes allows the hardware configuration of the microcontroller to be selected. They have no address in the memory map and can be accessed only in programming mode (for example using a standard ST7 programming tool). The default content of the FLASH is fixed to FFh. To program directly the FLASH devices using ICP, FLASH devices are shipped to customers with a reserved internal clock source enabled. In masked ROM devices, the option bytes are fixed in hardware by the ROM code (see option list). OPTION BYTE 0 OPT7 = WDGHALT Watchdog reset on HALT This option bit determines if a RESET is generated when entering HALT mode while the Watchdog is
STATIC OPTION BYTE 0 7 Reserved P LLOFF WDG HALT SW PKG 1 1 0 1 0 FMP_R 7 AFI_MA P 1 1 0 1 O S C T Y P E O S C R A N GE 1 1 0 0 1 1 0 1 Reserved 1
active. 0: No Reset generation when entering Halt mode 1: Reset generation when entering Halt mode OPT6 = WDGSW Hardware or software watchdog This option bit selects the watchdog type. 0: Hardware (watchdog always enabled) 1: Software (watchdog to be enabled by software) OPT5 = Reserved, must be kept at default value. OPT4 = LVD Voltage detection This option bit enables the voltage detection block (LVD).
Selected Low Voltage Detector LVD Off LVD On VD 1 0
OPT3 = PLL OFF PLL activation This option bit activates the PLL which allows multiplication by two of the main input clock frequency. The PLL is guaranteed only with an input frequency between 2 and 4 MHz. 0: PLL x2 enabled 1: PLL x2 disabled Caution: The PLL can be enabled only if the "OSC RANGE" (OPT11:10) bits are configured to "MP 2~4 MHz". Otherwise, the device functionality is not guaranteed.
STATIC OPTION BYTE 1 0 R ST C 1
LVD
Default(*)
1
1
1
1
1
1
(*): Option bit values programmed by ST
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FLASH OPTION BYTES (Cont'd) OPT2:1 = PKG[1:0] Package selection These option bits select the device package.
P KG Selected Package 1 LQFP 64 LQFP 44 LQFP 32 1 0 0 0 x 1 0
AFI Mapping 0 T16_ICAP2 is mapped on PD1 T16_ICAP2 is mapped on PC1
AFI_MAP(0) 0 1
OPT5:4 = OSCTYPE[1:0] Oscillator Type These option bits select the ST7 main clock source type.
OSC T YPE Clock Source 1 Resonator Oscillator Reserved Reserved internal clock source (used only in ICC mode) External Source 0 0 1 1 0 0 1 0 1
Note: Pads that are not bonded to external pins are in input pull-up configuration when the package selection option bits have been properly programmed. The configuration of these pads must be kept in reset state to avoid added current consumption. OPT0 = FMP_R Flash memory read-out protection Read-out protection, when selected provides a protection against program memory content extraction and against write access to Flash memory. Erasing the option bytes when the FMP_R option is selected causes the whole user memory to be erased first, and the device can be reprogrammed. Refer to Section 4.3.1 and the ST7 Flash Programming Reference Manual for more details. 0: Read-out protection enabled 1: Read-out protection disabled OPTION BYTE 1 OPT7:6 = AFI_MAP[1:0] AFI Mapping These option bits allow the mapping of some of the Alternate Functions to be changed.
AFI Mapping 1 T16_OCMP1 on PD3 T16_OCMP2 on PD5 T16_ICAP1 on PD4 LINSCI2_SCK not available LINSCI2_TDO not available LINSCI2_RDI not available T16_OCMP1 on PB6 T16_OCMP2 on PB7 T16_ICAP1 on PC0 LINSCI2_SCK on PD3 LINSCI2_TDO on PD5 LINSCI2_RDI on PD4 AFI_M A P(1)
OPT3:2 = OSCRANGE[1:0] Oscillator range If the resonator oscillator type is selected, these option bits select the resonator oscillator. This selection corresponds to the frequency range of the resonator used. If external source is selected with the OSCTYPE option, then the OSCRANGE option must be selected with the corresponding range.
OS CRANGE Typ. Freq. Range 1 LP MP MS HS 1~2 MHz 2~4 MHz 4~8 MHz 8~16 MHz 0 0 1 1 0 0 1 0 1
0
OPT1 = Reserved OPT0 = RSTC RESET clock cycle selection This option bit selects the number of CPU cycles inserted during the RESET phase and when exiting HALT mode. For resonator oscillators, it is advised to select 4096 due to the long crystal stabilization time. 0: Reset phase with 4096 CPU cycles 1: Reset phase with 256 CPU cycles
1
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DEVICE CONFIGURATION AND ORDER INFORMATION (cont'd) 14.2 TRANSFER OF CUSTOMER CODE Customer code is made up of the ROM/FASTROM contents and the list of the selected options (if any). The ROM/FASTROM contents are to be sent on diskette, or by electronic means, with the S19 hexadecimal file generated by the development tool. All unused bytes must be set to FFh. The selected options are communicated to STMicroelectronics using the correctly completed OPTION LIST appended. Figure 150. ROM Factory Coded Device Types
DEVICE PACKAGE VERSION / XXX Code name (defined by STMicroelectronics) 6 = Standard -40 to +85 C 3 = Standard -40 to +125 C
Refer to application note AN1635 for information on the counter listing returned by ST after code has been transferred. The STMicroelectronics Sales Organization will be pleased to provide detailed information on contractual points.
T= Low Profile Quad Flat Pack ST72561AR9, ST72561AR7, ST72561AR6, ST72561AR4 ST72561J9, ST72561J7, ST72561J6, ST72561J4 ST72561K9,ST72561K7, ST72561K6, ST72561K4
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TRANSFER OF CUSTOMER CODE (cont'd) Figure 151. FASTROM Factory Coded Device Types
DEVICE PACKAGE VERSION / XXX Code name (defined by STMicroelectronics) 6 = -40 to +85 C 3 = -40 to +125 C
T= Low Profile Quad Flat Pack ST72P561AR9, ST72P561AR7, ST72P561AR6, ST72P561AR4 ST72P561J9,ST72P561J7, ST72P561J6, ST72P561J4 ST72P561K9,ST72P561K7 ST72P561K6,ST72P561K4
Figure 152. FLASH Device Types
D EVIC E P A C K A G E V E R S I O N 6 = -40 to +85 C 3 = -40 to +125 C
T= Low Profile Quad Flat Pack ST72F561AR9, ST72F561AR7, ST72F561AR6 ST72F561J9, ST72F561J7,ST72F561J64 ST72F561K9, ST72F561K7, ST72F561K6
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TRANSFER OF CUSTOMER CODE (Cont'd)
ST72561 MICROCONTROLLER OPTION LIST (Last update: September 2006)
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . Contact . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . Phone No . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . Reference/ROM Code* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . *The ROM/FASTROM code name is assigned by STMicroelectronics. ROM/FASTROM code must be sent in .S19 format. .Hex extension cannot be processed. Device Type/Memory Size/Package (check only one option) Customer Address
ROM :
| | | | | | FASTRO M: | | | |
-----------------------| Package -----------------------| LQFP64 10x10: | L QFP44: | L QFP32: | -----------------------| Package -----------------------| LQFP64 10x10: | LQFP44: | LQFP32: |
------------------------- | 60K ------------------------- | [ ] ST72561AR9 | [ ] ST72561J9 | [ ] ST72561K9 | ------------------------- | 60K ------------------------- | [ ] ST72P561AR9 | [ ] ST72P561J9 | [ ] ST72P561K9 |
------------------------- | 48K ------------------------- | [ ] ST72561AR7 | [ ] ST72561J7 | [ ] ST72561K7 | ------------------------- | 48K ------------------------- | [ ] ST72P561AR7 | [ ] ST72P561J7 | [ ] ST72P561K7 |
------------------------ | 32K ------------------------ | [ ] ST72561AR6 | [ ] ST72561J6 | [ ] ST72561K6 | ------------------------ | 32K ------------------------ | [ ] ST72P561AR6 | [ ] ST72P561J6 | [ ] ST72P561K6 |
------------------------ | 16K ------------------------ | [ ] ST72561AR4 | [ ] ST72561J4 | [ ] ST72561K4 | ------------------------ | 16K ------------------------ | [ ] ST72P561AR4 | [ ] ST72P561J4 | [ ] ST72P561K4 |
Conditioning: [ ] Tray [ ] Tape & Reel Special Marking: [ ] No [ ] Yes "_ _ _ _ _ _ _ _ _ _ " (10 char. max) Authorized characters are letters, digits, '.', '-', '/' and spaces only. Temp. Range. Please refer to datasheet for specific sales conditions: --------------------------------------| Temp. Range --------------------------------------[] | -40C to +85C [] | -40C to +125C Clock Source Selection: Oscillator/External source range: [ ] LP: Low power (1 to 2 MHz) [ ] MP: Medium power (2 to 4 MHz) [ ] MS: Medium speed (4 to 8 MHz) [ ] HS: High speed (8 to 16 MHz) [ ] Disabled [ ] Enabled [ ] Disabled [ ] Enabled [ ] Software Activation [ ] Hardware Activation [ ] Reset [ ] No Reset [ ] Disabled [ ] 256 Cycles [ ] 4096 Cycles [ ] Mapped (AFIMAP[1] = 1) [ ] On PC1 (AFIMAP[0] = 1) [ ] Enabled [ ] Resonator: [ ] External Source
LVD PLL1 Watchdog Selection Watchdog Reset on Halt Read-out Protection Reset Delay LINSCI2 Mapping T16_ICAP2 Mapping
[ ] Not available (AFIMAP[1] = 0) [ ] On PD1 (AFIMAP[0] = 0)
Comments: Supply Operating Range in the application: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Notes Signature Date
1 If
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
PLL is enabled, medium power (2 to 4 MHz range) has to be selected (MP)
Please download the latest version of this option list from: http://www.st.com
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15 DEVELOPMENT TOOLS
Full details of tools available for the ST7 from third party manufacturers can be obtained from the STMicroelectronics Internet site: www.st.com/mcu Tools from iSystem and Hitex include C compliers, emulators and gang programmers. Note: Before designing the board layout, it is recommended to check the overall dimensions of the socket as they may be greater than the dimensions of the device. For footprint and other mechanical information about these sockets and adapters, refer to the manufacturer's datasheet. ST Programming Tools ST7MDT25-EPB: For in-socket or ICC programming ST7-STICK: For ICC programming
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16 IMPORTANT NOTES
16.1 ALL DEVICES 16.1.1 RESET Pin Protection with LVD Enabled As mentioned in note 2 below Figure 134 on page 240, when the LVD is enabled, it is recommended not to connect a pull-up resistor or capacitor. A 10nF pull-down capacitor is required to filter noise on the reset line. 16.1.2 Clearing Active Interrupts Outside Interrupt Routine When an active interrupt request occurs at the same time as the related flag or interrupt mask is being cleared, the CC register may be corrupted. Concurrent interrupt context The symptom does not occur when the interrupts are handled normally, that is, when: The interrupt request is cleared (flag reset or interrupt mask) within its own interrupt routine The interrupt request is cleared (flag reset or interrupt mask) within any interrupt routine The interrupt request is cleared (flag reset or interrupt mask) in any part of the code while this interrupt is disabled If these conditions are not met, the symptom can be avoided by implementing the following sequence: Perform SIM and RIM operation before and after resetting an active interrupt request Example: SIM reset flag or interrupt mask RIM Nested interrupt context The symptom does not occur when the interrupts are handled normally, that is, when: The interrupt request is cleared (flag reset or interrupt mask) within its own interrupt routine The interrupt request is cleared (flag reset or interrupt mask) within any interrupt routine with higher or identical priority level The interrupt request is cleared (flag reset or interrupt mask) in any part of the code while this interrupt is disabled If these conditions are not met, the symptom can be avoided by implementing the following sequence: PUSH CC SIM reset flag or interrupt mask POP CC 16.1.3 External Interrupt Missed To avoid any risk of generating a parasitic interrupt, the edge detector is automatically disabled for one clock cycle during an access to either DDR and OR. Any input signal edge during this period will not be detected and will not generate an interrupt. This case can typically occur if the application refreshes the port configuration registers at intervals during runtime. Workaround The workaround is based on software checking the level on the interrupt pin before and after writing to the PxOR or PxDDR registers. If there is a level change (depending on the sensitivity programmed for this pin) the interrupt routine is invoked using the call instruction with three extra PUSH instructions before executing the interrupt routine (this is to make the call compatible with the IRET instruction at the end of the interrupt service routine). But detection of the level change does ensure that edge occurs during the critical 1 cycle duration and the interrupt has been missed. This may lead to occurrence of same interrupt twice (one hardware and another with software call). To avoid this, a semaphore is set to '1' before checking the level change. The semaphore is changed to level '0' inside the interrupt routine. When a level change is detected, the semaphore status is checked and if it is '1' this means that the last interrupt has been missed. In this case, the interrupt routine is invoked with the call instruction. There is another possible case, that is, if writing to PxOR or PxDDR is done with global interrupts disabled (interrupt mask bit set). In this case, the semaphore is changed to '1' when the level change is detected. Detecting a missed interrupt is done after the global interrupts are enabled (interrupt mask bit reset) and by checking the status of the semaphore. If it is '1' this means that the last interrupt was missed and the interrupt routine is invoked with the call instruction. To implement the workaround, the following software sequence is to be followed for writing into the PxOR/PxDDR registers. The example is for Port PF1 with falling edge interrupt sensitivity. The
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IMPORTANT NOTES (Cont'd) software sequence is given for both cases (global interrupt disabled/enabled). Case 1: Writing to PxOR or PxDDR with Global Interrupts Enabled: LD A,#01 LD sema,A ; set the semaphore to '1' LD A,PFDR AND A,#02 LD X,A ; store the level before writing to PxOR/PxDDR LD A,#$90 LD PFDDR,A ; Write to PFDDR LD A,#$ff LD PFOR,A ; Write to PFOR LD A,PFDR AND A,#02 LD Y,A ; store the level after writing to PxOR/PxDDR LD A,X ; check for falling edge cp A,#02 jrne OUT TNZ Y jrne OUT LD A,sema ; check the semaphore status if edge is detected CP A,#01 jrne OUT call call_routine; call the interrupt routine OUT:LD A,#00 LD sema,A .call_routine ; entry to call_routine P US H A P US H X PUSH CC .ext1_rt ; entry to interrupt routine LD A,#00 LD sema,A IRET Case 2: Writing to PxOR or PxDDR with Global Interrupts Disabled: SIM ; set the interrupt mask LD A,PFDR AND A,#$02
LD X,A ; store the level before writing to PxOR/PxDDR LD A,#$90 LD PFDDR,A; Write into PFDDR LD A,#$ff LD PFOR,A ; Write to PFOR LD A,PFDR AND A,#$02 LD Y,A ; store the level after writing to PxOR/ PxDDR LD A,X ; check for falling edge cp A,#$02 jrne OUT TNZ Y jrne OUT LD A,#$01 LD sema,A ; set the semaphore to '1' if edge is detected RIM ; reset the interrupt mask LD A,sema ; check the semaphore status CP A,#$01 jrne OUT call call_routine; call the interrupt routine RIM OUT: RIM JP while_loop .call_routine ; entry to call_routine P US H A P US H X PUSH CC .ext1_rt ; entry to interrupt routine LD A,#$00 LD sema,A IRET 16.1.4 Unexpected Reset Fetch If an interrupt request occurs while a "POP CC" instruction is executed, the interrupt controller does not recognise the source of the interrupt and, by default, passes the RESET vector address to the CPU. Workaround To solve this issue, a "POP CC" instruction must always be preceded by a "SIM" instruction.
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IMPORTANT NOTES (Cont'd) 16.1.5 Header Time-out Does Not Prevent Wake-up from Mute Mode Normally, when LINSCI is configured in LIN slave mode, if a header time-out occurs during a LIN header reception (that is, header length > 57 bits), the LIN Header Error bit (LHE) is set, an interrupt occurs to inform the application but the LINSCI should stay in mute mode, waiting for the next header reception. Problem Description The LINSCI sampling period is Tbit / 16. If a LIN Header time-out occurs between the 9th and the 15th sample of the Identifier Field Stop Bit (refer to Figure 153), the LINSCI wakes up from mute mode. Nevertheless, LHE is set and LIN Header Detection Flag (LHDF) is kept cleared. In addition, if LHE is reset by software before this 15th sample (by accessing the SCISR register and Figure 153. Header Reception Event Sequence
reading the SCIDR register in the LINSCI interrupt routine), the LINSCI will generate another LINSCI interrupt (due to the RDRF flag setting). Impact on application Software may execute the interrupt routine twice after header reception. Moreover, in reception mode, as the receiver is no longer in mute mode, an interrupt will be generated on each data byte reception. Workaround The problem can be detected in the LINSCI interrupt routine. In case of timeout error (LHE is set and LHLR is loaded with 00h), the software can check the RWU bit in the SCICR2 register. If RWU is cleared, it can be set by software. Refer to Figure 154 on page 261. Workaround is shown in bold characters.
LIN Synch Break
LIN Synch Field
Identifier Field
T HEADER
ID field STOP bit Critical Window Active mode is set (RWU is cleared)
RDRF flag is set
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IMPORTANT NOTES (Cont'd) Figure 154.LINSCI Interrupt Routine @interrupt void LINSCI_IT ( void ) /* LINSCI interrupt routine */ { /* clear flags */ SCISR_buffer = SCISR; SCIDR_buffer = SCIDR; if ( SCISR_buffer & LHE )/* header error ? */ { if (!LHLR)/* header time-out? */ { if ( !(SCICR2 & RWU) )/* active mode ? */ { _asm("sim");/* disable interrupts */ SCISR; SCIDR;/* Clear RDRF flag */ SCICR2 |= RWU;/* set mute mode */ SCISR; SCIDR;/* Clear RDRF flag */ SCICR2 |= RWU;/* set mute mode */ _asm("rim");/* enable interrupts */ } } } } 16.1.6 TIMD set simultaneously with OC interrupt If the 16-bit timer is disabled at the same time the output compare event occurs then the output compare flag gets locked and cannot be cleared before the timer is enabled again. Impact on the application: If output compare interrupt is enabled, then the output compare flag cannot be cleared in the timer interrupt routine. Consequently the interrupt service routine is called repeatedly and the application get stuck which causes the watchdog reset if enabled by the application. Workaround: Disable the timer interrupt before disabling the timer. Again while enabling, first enable the timer, then the timer interrupts. Perform the following to disable the timer: TACR1 or TBCR1 = 0x00h; // Disable the compare interrupt TACSR | or TBCSR | = 0x40; // Disable the timer Perform the following to enable the timer again: TACSR & or TBCSR &= ~0x40; // Enable the timer TACR1 or TBCR1 = 0x40; // Enable the compare interrupt
Example using Cosmic compiler syntax
16.1.7 CAN FIFO Corruption The beCAN FIFO gets corrupted when a message is received and simultaneously a message is released while FMP = 2. For details and a description of the workaround refer to Section 10.9.7.1 on page 187. 16.2 FLASH/FASTROM DEVICES ONLY 16.2.1 LINSCI Wrong Break Duration SCI mode A single break character is sent by setting and resetting the SBK bit in the SCICR2 register. In some cases, the break character may have a longer duration than expected: - 20 bits instead of 10 bits if M = 0 - 22 bits instead of 11 bits if M = 1 In the same way, as long as the SBK bit is set, break characters are sent to the TDO pin. This may lead to generate one break more than expected. Occurrence The occurrence of the problem is random and proportional to the baud rate. With a transmit frequency of 19200 baud (fCPU = 8 MHz and
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SCIBRR = 0xC9), the wrong break duration occurrence is around 1%. Workaround If this wrong duration is not compliant with the communication protocol in the application, software can request that an Idle line be generated before the break character. In this case, the break duration is always correct assuming the application is not doing anything between the idle and the break. This can be ensured by temporarily disabling interrupts. The exact sequence is:
- Disable interrupts - Reset and Set TE (IDLE request) - Set and Reset SBK (Break Request) - Re-enable interrupts LIN mode If the LINE bit in the SCICR3 is set and the M bit in the SCICR1 register is reset, the LINSCI is in LIN master mode. A single break character is sent by setting and resetting the SBK bit in the SCICR2 register. In some cases, the break character may have a longer duration than expected: - 24 bits instead of 13 bits
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IMPORTANT NOTES (Cont'd) Occurrence The occurrence of the problem is random and proportional to the baud rate. With a transmit frequency of 19200 baud (fCPU = 8 MHz and SCIBRR = 0xC9), the wrong break duration occurrence is around 1%. Analysis The LIN protocol specifies a minimum of 13 bits for the break duration, but there is no maximum value. Nevertheless, the maximum length of the header is specified as (14+10+10+1) x 1.4 = 49 bits. This is composed of: - the synch break field (14 bits) - the synch field (10 bits) - the identifier field (10 bits) Every LIN frame starts with a break character. Adding an idle character increases the length of each header by 10 bits. When the problem occurs, the header length is increased by 11 bits and becomes ((14+11)+10+10+1) = 45 bits. To conclude, the problem is not always critical for LIN communication if the software keeps the time between the sync field and the ID smaller than 4 bits, that is, 208s at 19200 baud.
The workaround is the same as for SCI mode but considering the low probability of occurrence (1%), it may be better to keep the break generation sequence as it is. 16.2.2 16-bit and 8-bit Timer PWM Mode In PWM mode, the first PWM pulse is missed after writing the value FFFCh in the OC1R or OC2R register. 16.3 ROM DEVICES ONLY 16.3.1 16-bit Timer PWM Mode Buffering Feature Change In all devices, the frequency and period of the PWM signal are controlled by comparing the counter with a 16-bit buffer updated by the OCiHR and OCiLR registers. In ROM devices, contrary to the description in Section 10.5.3.5 on page 103, the output compare function is not inhibited after a write instruction to the OCiHR register. Instead the buffer update at the end of the PWM period is inhibited until OCiLR is written. This improved buffer handling is fully compatible with applications written for Flash devices.
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17 REVISION HISTORY
Date Revision Main changes Added standard version 16K ROM/Flash devices Modified data retention in Section 12.7 Added "6" and "3" standard version device type coding to Figure 152 and Figure 150 on page 254 Modified power consumption Section 12.4 Added CDM in Section 12.8.3.1 Added "External interrupt missed" Section 16.1.3 Replaced TQFP with LQFP packages throughout document Changed device summary on page 1 Changed Section 9.2.1 on page 46 Changed title of Section 9.6 on page 50 from "I/O Port Implementation" to "I/O Port Register Configurations" Changed Section 10.6.3.3 on page 114 Corrected name of bit 5 in SPICSR register in Table 22 on page 121 Changed Section 12.5.4 on page 228 Added links to Table 39 and Table 40 in Section 12.8.3 on page 233 Removed EMC protection circuitry in Figure 135 on page 240 (device works correctly without these components) Changed Section 12.12.1 on page 243 Changed title of Figure 146 on page 249 Changed title of Figure 124 on page 210 Changed title of Figure 147 on page 249 Changed notes in Section 13.2 on page 251 Changed AFI mapping for "OPTION BYTE 1" on page 253 Chan |
