ST7232A
8-BIT MICROCONTROLLER WITH 8K FLASH/ROM, ADC, 4 TIMERS, SPI, SCI INTERFACE
Memories 8K dual voltage High Density Flash (HDFlash) or ROM with read-out protection capability. InApplication Programming and In-Circuit Programming for HDFlash devices 384 bytes RAM HDFlash endurance: 100 cycles, data retention: 40 years at 85C Clock, Reset And Supply Management Clock sources: crystal/ceramic resonator oscillators and bypass for external clock PLL for 2x frequency multiplication Four Power Saving Modes: Halt, Active-Halt, Wait and Slow Interrupt Management Nested interrupt controller 14 interrupt vectors plus TRAP and RESET 6 external interrupt lines (on 4 vectors) Up to 32 I/O Ports 32/24 multifunctional bidirectional I/O lines 22/17 alternate function lines 12/10 high sink outputs 4Timers Main Clock Controller with: Real time base, Beep and Clock-out capabilities Configurable watchdog timer Two 16-bit Timers with: 2 input captures, 2 output compares, PWM and pulse generator modes 2 Communications Interfaces SPI synchronous serial interface SCI asynchronous serial interface
TQFP32 7x7
S D IP32 400mil
TQ FP44
SDIP42
1 Analog peripheral (low current coupling) 10-bit ADC with up to 12 robust input ports 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 In-Circuit Testing capability
Device Summary
Features
Program memory - bytes RAM (stack) bytes Operating Voltage Temp. Range Package
ST72F32AK1 ST72F32AK2 ST72F32AJ1 ST72F32AJ2 ST7232AK1 ST7232AK2 ST7232AJ1 ST7232AJ2
FLASH 4K FLASH 8K FLASH 4K FLASH 8K ROM 4K ROM 8K ROM 4K ROM 8K
384 (256) 3.8V to 5.5V up to -40C to +125C SDIP32 400mils / SDIP42 600mils / TQFP32 7x7 TQFP44 10x10
384 (256) 3.8V to 5.5V up to -40C to +125C SDIP32 400mils / SDIP42 600mils / TQFP32 7x7 TQFP44 10x10
Rev. 2
December 2005 1/157
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Table of Contents
1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2 PIN DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3 REGISTER & MEMORY MAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4 FLASH PROGRAM MEMORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4.2 4.3 4.4 4.5 4.6 4.7 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 STRUCTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4.3.1 Read-out Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 ICC INTERFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 ICP (IN-CIRCUIT PROGRAMMING) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 IAP (IN-APPLICATION PROGRAMMING) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 RELATED DOCUMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.7.1 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5 CENTRAL PROCESSING UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5.2 5.3 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 CPU REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6 SUPPLY, RESET AND CLOCK MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 6.1 PHASE LOCKED LOOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 6.2 6.3 MULTI-OSCILLATOR (MO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 RESET SEQUENCE MANAGER (RSM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 25 25 26 26 27
6.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3.2 Asynchronous External RESET pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3.3 External Power-On RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3.4 Internal Watchdog RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4 SYSTEM INTEGRITY MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.4.1 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 7 INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 7.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 7.2 7.3 7.4 7.5 7.6 7.7 MASKING AND PROCESSING FLOW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 INTERRUPTS AND LOW POWER MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 CONCURRENT & NESTED MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 INTERRUPT REGISTER DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 EXTERNAL INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 7.6.1 I/O Port Interrupt Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 EXTERNAL INTERRUPT CONTROL REGISTER (EICR) . . . . . . . . . . . . . . . . . . . . . . . 35
8 POWER SAVING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 8.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 8.2 8.3 8.4 SLOW MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 WAIT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 ACTIVE-HALT AND HALT MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 157 8.4.1 ACTIVE-HALT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 8.4.2 HALT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
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9 I/O PORTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 9.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 9.2 FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 42 42 42 45 9.2.1 Input Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2.2 Output Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2.3 Alternate Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.3 I/O PORT IMPLEMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.4 9.5
LOW POWER MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
9.5.1 I/O Port Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 10 ON-CHIP PERIPHERALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 10.1 WATCHDOG TIMER (WDG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 10.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1.2 Main Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1.4 How to Program the Watchdog Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1.5 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1.6 Hardware Watchdog Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1.7 Using Halt Mode with the WDG (WDGHALT option) . . . . . . . . . . . . . . . . . . . . . . . 10.1.8 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1.9 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2 MAIN CLOCK CONTROLLER WITH REAL TIME CLOCK AND BEEPER (MCC/RTC) . 10.2.1 Programmable CPU Clock Prescaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.2 Clock-out Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.3 Real Time Clock Timer (RTC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.4 Beeper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.5 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.7 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3 16-BIT TIMER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3.2 Main Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3.4 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3.6 Summary of Timer modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3.7 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4 SERIAL PERIPHERAL INTERFACE (SPI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4.2 Main Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4.3 General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4.4 Clock Phase and Clock Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4.5 Error Flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4.6 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4.7 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 . ... 10.4.8 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.5 SERIAL COMMUNICATIONS INTERFACE (SCI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 48 48 49 51 51 51 51 51 53 53 53 53 53 54 54 54 56 56 56 56 68 68 68 69 76 76 76 76 80 81 83 83 84 87
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10.5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 10.5.2 Main Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 10.5.3 General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 10.5.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 10.5.5 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 10.5.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 10.5.7 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 10.6 10-BIT A/D CONVERTER (ADC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 10.6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.6.2 Main Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.6.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.6.4 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.6.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.6.6 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 INSTRUCTION SET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 CPU ADDRESSING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1.1 Inherent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1.2 Immediate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1.3 Direct . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1.4 Indexed (No Offset, Short, Long) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1.5 Indirect (Short, Long) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1.6 Indirect Indexed (Short, Long) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1.7 Relative mode (Direct, Indirect) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 INSTRUCTION GROUPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 103 104 104 104 105 107 107 108 108 108 108 108 109 109 110
12 ELECTRICAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 12.1 PARAMETER CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 12.1.1 Minimum and Maximum values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1.2 Typical values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1.3 Typical curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1.4 Loading capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1.5 Pin input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.2 ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.2.1 Voltage Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.2.2 Current Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.2.3 Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.3 OPERATING CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 113 113 113 113 114 114 114 115 115
12.3.1 Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 12.4 SUPPLY CURRENT CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 12.4.1 CURRENT CONSUMPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.4.2 Supply and Clock Managers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.4.3 On-Chip Peripherals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.5 CLOCK AND TIMING CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 118 119 120
12.5.1 General Timings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 12.5.2 External Clock Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 12.5.3 Crystal and Ceramic Resonator Oscillators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 157 12.5.4 PLL Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 12.6 MEMORY CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
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12.6.1 RAM and Hardware Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 12.6.2 FLASH Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 12.7 EMC CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 12.7.1 Functional EMS (Electro Magnetic Susceptibility) . . . . . . . . . . . . . . . . . . . . . . . . 12.7.2 Electro Magnetic Interference (EMI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.7.3 Absolute Maximum Ratings (Electrical Sensitivity) . . . . . . . . . . . . . . . . . . . . . . . . 12.8 I/O PORT PIN CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 126 127 128
12.8.1 General Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 12.8.2 Output Driving Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 12.9 CONTROL PIN CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 12.9.1 Asynchronous RESET Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 12.9.2 ICCSEL/VPP Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 12.10 TIMER PERIPHERAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 12.10.116-Bit Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 12.11 COMMUNICATION INTERFACE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . 135 12.11.1SPI - Serial Peripheral Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 12.12 10-BIT ADC CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 12.12.1Analog Power Supply and Reference Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.12.2General PCB Design Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.12.3ADC Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 PACKAGE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.1 PACKAGE MECHANICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 139 140 141 141
13.2 THERMAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 13.3 SOLDERING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 14 ST7232A DEVICE CONFIGURATION AND ORDERING INFORMATION . . . . . . . . . . . . . . . 145 14.1 FLASH OPTION BYTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 14.2 ROM DEVICE ORDERING INFORMATION AND TRANSFER OF CUSTOMER CODE 147 14.3 VERSION-SPECIFIC SALES CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 14.4 FLASH DEVICE ORDERING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 14.5 DEVELOPMENT TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 14.5.1 Socket and Emulator Adapter Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151 14.6 ST7 APPLICATION NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 15 KNOWN LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 15.1 ALL FLASH AND ROM DEVICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 15.1.1 Safe Connection of OSC1/OSC2 Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.1.2 Unexpected Reset Fetch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.1.3 Clearing active interrupts outside interrupt routine . . . . . . . . . . . . . . . . . . . . . . . . 15.1.4 16-bit Timer PWM Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.1.5 SCI Wrong Break duration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.1.6 39-Pulse ICC Entry Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.2 ROM DEVICES ONLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 154 154 154 154 155 155
15.2.1 I/O Port A and F Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 15.2.2 External clock source with PLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 16 REVISION HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 156 ...
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To obtain the most recent version of this datasheet, please check at www.st.com>products>technical literature>datasheet. Please also pay special attention to the Section "KNOWN LIMITATIONS" on page 154.
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1 INTRODUCTION
The ST72F32A and ST7232A devices are members of the ST7 microcontroller family designed for the 5V operating range. The 32 and 44-pin devices are designed for midrange applications 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. Figure 1. Device Block Diagram
8-BIT CORE ALU RESET VPP VSS VDD CONTROL
Under software control, all devices can be placed in WAIT, SLOW, ACTIVE-HALT or HALT mode, reducing power consumption when the application is in idle or stand-by state. The enhanced instruction set and addressing modes of the ST7 offer both power and flexibility to software developers, enabling the design of highly efficient and compact application code. In addition to standard 8-bit data management, all ST7 microcontrollers feature true bit manipulation, 8x8 unsigned multiplication and indirect addressing modes.
PROGRAM MEMORY (8K Bytes) RAM (384 Bytes)
WATCHDOG OSC1 OSC2 OSC ADDRESS AND DATA BUS MCC/RTC/BEEP
PORT A
PORT F TIMER A BEEP PORT E
PORT B
PORT C SCI TIMER B PORT D SPI 10-BIT ADC VAREF VSSA
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2 PIN DESCRIPTION
Figure 2. 32-Pin SDIP Package Pinout
(HS) PB4 AIN0 / PD0 AIN1 / PD1 VAREF VSSA MCO / AIN8 / PF0 BEEP / (HS) PF1 OCMP1_A / AIN10 / PF4 ICAP1_A / (HS) PF6 EXTCLK_A / (HS) PF7 AIN12 / OCMP2_B / PC0 AIN13 / OCMP1_B / PC1 ICAP2_B / (HS) PC2 ICAP1_B / (HS) PC3 ICCDATA/ MISO / PC4 AIN14 / MOSI / PC5
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
ei3
32 ei2 31 30 29 28
PB3 PB0 PE1 / RDI PE0 / TDO VDD_2 OSC1 OSC2 VSS_2 RESET VPP / ICCSEL PA7 (HS) PA6 (HS) PA4 (HS) PA3 (HS) PC7 / SS / AIN15 PC6 / SCK / ICCCLK (HS) 20mA high sink capability eix associated external interrupt vector
ei1
27 26 25 24 23 22 21 20 ei0 19 18 17
Figure 3. 32-Pin TQFP 7x7 Package Pinout
VAREF VSSA MCO / AIN8 / PF0 BEEP / (HS) PF1 OCMP1_A / AIN10 / PF4 ICAP1_A / (HS) PF6 EXTCLK_A / (HS) PF7 AIN12 / OCMP2_B / PC0
32 31 30 29 28 27 26 25 24 1 ei3 ei2 23 2 22 3 ei1 21 4 20 5 19 6 18 7 ei0 17 8 9 10 11 12 13 14 15 16 AIN13 / OCMP1_B / PC1 ICAP2_B / (HS) PC2 ICAP1_B / (HS) PC3 ICCDATA / MISO / PC4 AIN14 / MOSI / PC5 ICCCLK / SCK / PC6 AIN15 / SS / PC7 (HS) PA3
PD1 / AIN1 PD0 / AIN0 PB4 (HS) PB3 PB0 PE1 / RDI PE0 / TDO VDD_2
OSC1 OSC2 VSS_2 RESET VPP / ICCSEL PA7 (HS) PA6 (HS) PA4 (HS)
(HS) 20mA high sink capability eix associated external interrupt vector
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PIN DESCRIPTION (Cont'd) Figure 4. 42-Pin SDIP and 44-Pin TQFP Package Pinouts
RDI / PE1 PB0 PB1 PB2 PB3 (HS) PB4 AIN0 / PD0 AIN1 / PD1 AIN2 / PD2 AIN3 / PD3 AIN4 / PD4
44 43 42 41 40 39 38 37 36 35 34 1 33 2 32 3 31 ei0 ei2 4 30 5 29 ei3 6 28 7 27 8 26 9 25 ei1 10 24 11 23 12 13 14 15 16 17 18 19 20 21 22 AIN5 / PD5 VAREF VSSA MCO / AIN8 / PF0 BEEP / (HS) PF1 (HS) PF2 OCMP1_A / AIN10 / PF4 ICAP1_A / (HS) PF6 EXTCLK_A / (HS) PF7 VDD_0 VSS_0
PE0 / TDO VDD_2 OSC1 OSC2 VSS_2 RESET VPP / ICCSEL PA7 (HS) PA6 (HS) PA5 (HS) PA4 (HS)
VSS_1 VDD_1 PA3 (HS) PC7 / SS / AIN15 PC6 / SCK / ICCCLK PC5 / MOSI / AIN14 PC4 / MISO / ICCDATA PC3 (HS) / ICAP1_B PC2 (HS) / ICAP2_B PC1 / OCMP1_B / AIN13 PC0 / OCMP2_B / AIN12
(HS) PB4 AIN0 / PD0 AIN1 / PD1 AIN2 / PD2 AIN3 / PD3 AIN4 / PD4 AIN5 / PD5 V AREF VSSA MCO / AIN8 / PF0 BEEP / (HS) PF1 (HS) PF2 AIN10 / OCMP1_A / PF4 ICAP1_A / (HS) PF6 EXTCLK_A / (HS) PF7 AIN12 / OCMP2_B / PC0 AIN13 / OCMP1_B / PC1 ICAP2_B/ (HS) PC2 ICAP1_B / (HS) PC3 ICCDATA / MISO / PC4 AIN14 / MOSI / PC5
1 ei3 2 3 4 5 6 7 8 9 10 11 ei1 12 13 14 15 16 17 18 19 20 21
ei2
ei0
42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22
PB3 PB2 PB1 PB0 PE1 / RDI PE0 / TDO VDD_2 OSC1 OSC2 VSS_2 RESET VPP / ICCSEL PA7 (HS) PA6 (HS) PA5 (HS) PA4 (HS) VSS_1 VDD_1 PA3 (HS) PC7 / SS / AIN15 PC6 / SCK / ICCCLK (HS) 20mA high sink capability eix associated external interrupt vector
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PIN DESCRIPTION (Cont'd) For external pin connection guidelines, refer to See "ELECTRICAL CHARACTERISTICS" on page 113. Legend / Abbreviations for Table 1: Type: I = input, O = output, S = supply Input level: A = Dedicated analog input In/Output level: C = CMOS 0.3VDD/0.7VDD CT= CMOS 0.3VDD/0.7VDD with input trigger Output level: HS = 20mA high sink (on N-buffer only) Port and control configuration: Input: float = floating, wpu = weak pull-up, int = interrupt 1), ana = analog ports Output: OD = open drain 2), PP = push-pull Refer to "I/O PORTS" on page 42 for more details on the software configuration of the I/O ports. The RESET configuration of each pin is shown in bold. This configuration is valid as long as the device is in reset state. Table 1. Device Pin Description
Pin n TQFP44 TQFP32 Type SDIP42 SDIP32 Pin Name Level Output Input Port Input float wpu ana int Main function Output (after reset) OD X X X X X X X X X X X X X PP X X X X X X X Port B4 Port D0 Port D1 Port D2 Port D3 Port D4 Port D5 ADC Analog Input 0 ADC Analog Input 1 ADC Analog Input 2 ADC Analog Input 3 ADC Analog Input 4 ADC Analog Input 5
Alternate Function
6 7 8 9
1 30 1 2 31 2 3 32 3 4
PB4 (HS) PD0/AIN0 PD1/AIN1 PD2/AIN 2 PD3/AIN3 PD4/AIN4 PD5/AIN5
I/O CT I/O CT I/O CT I/O CT I/O CT I/O CT I/O CT S S I / O CT I/O CT I / O CT I/O CT I / O CT I/O CT S S I/O CT
HS
X X X X X X X
ei3 X X X X X X
10 5 11 6 12 7 13 8 14 9 1 2 4 5 6 7
VAREF VSSA PF0/MCO/AIN 8 PF1 (HS)/BEEP PF2 (HS)
Analog Reference Voltage for ADC Analog Ground Voltage X HS HS X X X HS HS X X X X X ei1 ei1 ei1 X X X X X X X X X X X X X X Port F0 Port F1 Port F2 Port F4 Port F6 Port F7 Timer A OutADC Analog put ComInput 10 pare 1 Timer A Input Capture 1 Timer A External Clock Source Main clock out (fCPU) ADC Analog Input 8
15 10 3 16 11 4 17 12 18 13 5 19 14 6
Beep signal output
8 9
PF4/OCMP1_A / AIN10 PF6 (HS)/ICAP1_A PF7 (HS)/ EXTCLK_A VDD_0 VSS_0 PC0/OCMP 2_B/ AIN12
20 15 7 10 21 22 23 16 8 11
Digital Main Supply Voltage Digital Ground Voltage X X X X X Port C0 Timer B OutADC Analog put ComInput 12 pare 2
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Pin n TQFP44 TQFP32 Type SDIP42 SDIP32 Pin Name
Level Output Input
Port Input fl oat wpu ana int
OD
PP
Main function Output (after reset)
Alternate Function
24 17 9 12
PC1/OCMP 1_B/ AIN13
I/O CT I/O CT I/O CT I/O CT HS HS
X X X X
X X X X
X
X X X X
X X X X
Port C1 Port C2 Port C3 Port C4
Timer B OutADC Analog put ComInput 13 pare 1 Timer B Input Capture 2 Timer B Input Capture 1 SPI Master In / Slave Out Data SPI Master Out / Slave In Data SPI Serial Clock SPI Slave Select (active low) ICC Data Input ADC Analog Input 14 ICC Clock Output ADC Analog Input 15
25 18 10 13 PC2 (HS)/ICAP2_B 26 19 11 14 PC3 (HS)/ICAP1_B 27 20 12 15 PC4/MISO/ICCDA TA
28 21 13 16 PC5/MOSI/A IN14 29 22 14 17 PC6/SCK/ICCC LK 30 23 15 18 PC7/SS/AIN15 31 24 16 19 PA3 (HS) 32 25 33 26 35 28 VDD_1 VSS_1 PA5 (HS)
I/O C T I / O CT I/O CT I/O CT S S I/O CT I/O CT I/O CT I/O CT HS HS HS HS HS
X X X X
X X X ei0
X
X X
X X X X
Port C5 Port C6 Port C7 Port A3
X
X X
Digital Main Supply Voltage Digital Ground Voltage X X X X X X X X T T X X Port A4 Port A5 Port A6 1) Port A7 1) Must be tied low. In the flash programming mode, this pin acts as the programming voltage input VPP. See Section 12.9.2 for more details. High voltage must not be applied to ROM devices. Top priority non maskable interrupt. Digital Ground Voltage Resonator oscillator inverter output External clock input or Resonator oscillator inverter input Digital Main Supply Voltage X X X X X X X X ei2 ei2 ei2 ei2 X X X X X X X X X X X X Port E0 Port E1 Port B0 Port B1 Port B2 Port B3 SCI Transmit Data Out SCI Receive Data In
34 27 17 20 PA4 (HS) 36 29 18 21 PA6 (HS) 37 30 19 22 PA7 (HS)
38 31 20 23 VPP /ICCSEL
I
39 32 21 24 RESE T 40 33 22 25 VSS_2 41 34 23 26 OSC 2 42 35 24 27 OSC1 43 36 25 28 VDD_2 44 37 26 29 PE0/TDO 1 38 2 7 3 0 PE1 / RDI 2 39 2 8 3 1 PB0 3 40 4 41 PB1 PB2
I/O CT S O I S I / O CT I/O CT I/O CT I/O CT I/O CT I/O CT
Caution: Negative current injection not allowed on this pin5)
5 42 2 9 3 2 PB3
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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. In the open drain output column, "T" defines a true open drain I/O (P-Buffer and protection diode to VDD are not implemented). See See "I/O PORTS" on page 42. and Section 12.8 I/O PORT PIN CHARACTERISTICS for more details. 3. OSC1 and OSC2 pins connect a crystal/ceramic resonator, or an external source to the on-chip oscillator; see Section 1 INTRODUCTION and Section 12.5 CLOCK AND TIMING CHARACTERISTICS for more details. 4. On the chip, each I/O port has 8 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. 5. For details refer to Section 12.8.1 on page 128
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3 REGISTER & MEMORY MAP
As shown in Figure 5, the MCU is capable of addressing 64K bytes of memories and I/O registers. The available memory locations consist of 128 bytes of register locations, up to 384 bytes of RAM and up to 8 Kbytes of user program memory. The RAM space includes up to 256 bytes for the stack from 0100h to 01FFh. Figure 5. Memory Map
0080h 0000h 007Fh 0080h
The highest address bytes contain the user reset and interrupt vectors. IMPORTANT: Memory locations marked as "Reserved" must never be accessed. Accessing a reserved area can have unpredictable effects on the device.
HW Registers (see Table 2)
Short Addressing RAM (zero page)
00FFh 0100h
RAM (384 Bytes)
047Fh 0480h
256 Bytes Stack
01FFh 0200h
Reserved Reserved
027Fh or 047Fh E000h
E000h FFDFh FFE0h FFFFh
Program Memory (4K or 8K) Interrupt & Reset Vectors (see Table 8)
8 KBytes
F000h
4 Kbytes
FFFFh
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Table 2. Hardware Register Map
Address 0000h 0001h 0002h 0003h 0004h 0005h 0006h 0007h 0008h 0009h 000Ah 000Bh 000Ch 000Dh 000Eh 000Fh 0010h 0011h 0012h to 0020h 0021h 0022h 0023h 0024h 0025h 0026h 0027h 0028h 0029h 002Ah 002Bh 002Ch 002Dh 002Eh to 0030h MC C MCCS R MCCB CR FLAS H W ATCHDOG SPIDR SPICR SPICSR ISPR0 ISPR1 ISPR2 ISPR3 EIC R FCSR WD G C R Block Register Label PADR PADDR PAOR PBDR PBDDR PBOR PCDR PCDDR PCOR PDADR PDDDR PDOR PEDR PEDDR PEOR PFDR PFDDR PFOR 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 Port F Data Register Port F Data Direction Register Port F Option Register Reset Status 00h1 ) 00h 00h 00h1 ) 00h 00h 00h1 ) 00h 00h 00h1 ) 00h 00h 00h1 ) 00h 00h 00h1 ) 00h 00h 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 / W2 ) R / W2 ) R/W R/W R/W
Port A 2)
Port B
2)
Port C
Port D
2)
Port E
2)
Port F 2)
Reserved Area (15 Bytes)
SPI
SPI Data I/O Register SPI Control Register SPI 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 Flash Control/Status Register Watchdog Control Register Reserved Area (1 Byte) Main Clock Control / Status Register Main Clock Controller: Beep Control Register
xxh 0xh 00h FFh FFh FFh FFh 00h 00h 7Fh
R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W
ITC
00h 00h
R/W R/W
Reserved Area (3 Bytes)
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Address 0031h 0032h 0033h 0034h 0035h 0036h 0037h 0038h 0039h 003Ah 003Bh 003Ch 003Dh 003Eh 003Fh 0040h 0041h 0042h 0043h 0044h 0045h 0046h 0047h 0048h 0049h 004Ah 004Bh 004Ch 004Dh 004Eh 004Fh 0050h 0051h 0052h 0053h 0054h 0055h 0056h 0057h 0058h to 006Fh 0070h 0071h 0072h 0073h 007Fh
Block
Register Label TACR2 TACR1 TACSR TAIC1HR TAIC1LR TAOC1HR TAOC1LR TACHR TACLR TAACHR TAACLR TAIC2HR TAIC2LR TAOC2HR TAOC2LR
Register Name Timer A Control Register 2 Timer A Control Register 1 Timer A Control/Status Register Timer A Input Capture 1 High Register Timer A Input Capture 1 Low Register Timer A Output Compare 1 High Register Timer A Output Compare 1 Low Register Timer A Counter High Register Timer A Counter Low Register Timer A Alternate Counter High Register Timer A Alternate Counter Low Register Timer A Input Capture 2 High Register Timer A Input Capture 2 Low Register Timer A Output Compare 2 High Register Timer A Output Compare 2 Low Register Reserved Area (1 Byte)
Reset Status 00h 00h xxxx x0xxb xxh xxh 80h 00h FFh FCh FFh FCh xxh xxh 80h 00h
Remarks 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
TIME R A
TIME R B
TBCR2 TBCR1 TBCSR TBIC1HR TBIC1LR TBOC1HR TBOC1LR TBCHR TBCLR TBACHR TBACLR TBIC2HR TBIC2LR TBOC2HR TBOC2LR SCISR SCIDR SCIBRR SCICR1 SCICR2 SCIERPR SCIETPR
Timer B Control Register 2 Timer B Control Register 1 Timer B Control/Status Register Timer B Input Capture 1 High Register Timer B Input Capture 1 Low Register Timer B Output Compare 1 High Register Timer B Output Compare 1 Low Register Timer B Counter High Register Timer B Counter Low Register Timer B Alternate Counter High Register Timer B Alternate Counter Low Register Timer B Input Capture 2 High Register Timer B Input Capture 2 Low Register Timer B Output Compare 2 High Register Timer B Output Compare 2 Low Register SCI Status Register SCI Data Register SCI Baud Rate Register SCI Control Register 1 SCI Control Register 2 SCI Extended Receive Prescaler Register Reserved area SCI Extended Transmit Prescaler Register
00h 00h xxxx x0xxb xxh xxh 80h 00h FFh FCh FFh FCh xxh xxh 80h 00h C0h xxh 00h x000 0000h 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
SCI
Reserved Area (24 Bytes)
AD C
ADCCSR ADCDRH ADCDRL
Control/Status Register Data High Register Data Low Register Reserved Area (13 Bytes)
00h 00h 00h
R/W Read Only Read Only
Legend: x=undefined, R/W=read/write
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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 3. Sectors available in Flash devices
Flash Size (bytes) 4K 8K > 8K Available Sectors Sector 0 Sectors 0,1 Sectors 0,1, 2
Three 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. 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 needs a minimum of 4 and up to 6 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) (See caution) 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 ICC CONNECTOR HE10 CONNECTOR TYPE
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 (optional, 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 management 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. Caution: External clock ICC entry mode is mandatory. Pin 9 must be connected to the OSC1 or OSCIN pin of the ST7 and OSC2 must be grounded.
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ICCSEL/VPP
ICCDATA
RESET
ICCCLK
OSC2
OSC1
VDD
VSS
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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, USB or CAN 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. 4.7.1 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 4. Flash Control/Status Register Address and Reset Value
Address (Hex.) 0029h 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 6 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 inst ructions. 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 (i.e. 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) 5 Crystal/Ceramic resonator oscillators 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 Figure 11. Clock, Reset and Supply Block Diagram
OSC2 OSC1 MULTIOSCILLATOR (MO) fOSC2 PLL (option) SYSTEM INTEGRITY MANAGEMENT RESET SEQUENCE RESET MANAGER (RSM) VSS VDD WATCHDOG MAIN CLOCK fCPU CONTROLLER WITH REALTIME CLOCK (MCC/RTC)
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. Figure 10. PLL Block Diagram
PLL x 2
fOSC 0 fOSC2 1
/2
PLL OPTION BIT
fOSC
SICSR
0 0 0 0 WDG RF
TIMER (WDG)
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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 4 crystal or ceramic resonator oscillators Each oscillator is optimized for a given frequency range in terms of consumption and is selectable through the option byte. The associated hardware configurations are shown in Table 5. 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 (>16MHz.), putting the ST7 in an unsafe/undefined state. The product behaviour must therefore be considered undefined when the OSC pins are left unconnected. External Clock Source In this 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 4 oscillators with different frequency ranges has to be done by option byte in order to reduce consumption (refer to Section 14.1 on page 145 for more details on the frequency ranges). In this mode of the multioscillator, the resonator and the load capacitors have to 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 5. ST7 Clock Sources
Hardware Configuration
External Clock
ST7 OS C1 OSC 2
EX TERNAL SO URCE
Crystal/Ceramic Resonators
ST7 OSC 1 OSC2
CL 1
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 two RESET sources as shown in Figure 13: External RESET source pulse 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 3 phases as shown in Figure 12: 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 stabilise 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. Figure 13. Reset Block Diagram The RESET vector fetch phase duration is 2 clock c ycles. Figure 12. RESET Sequence Phases
RESET
Active Phase INTERNAL RESET 256 or 4096 CLOCK CYCLES FETCH VECTOR
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 14). 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
WATCHDO G 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 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. Figure 14. RESET Sequences
EXTERNAL RESET WATCHDOG RESET
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 Watchdog RESET The RESET sequence generated by a internal Watchdog counter overflow is shown in Figure 14. Starting from the Watchdog counter underflow, the device RESET pin acts as an output that is pulled low during at least tw(RSTL)out.
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 6.4.1 Register Description SYSTEM INTEGRITY (SI) CONTROL/STATUS REGISTER (SICSR) Read / Write Reset Value: 0000 000x (00h) Bit 0 = WDGRF Watchdog reset flag This bit indicates that the last Reset was generated by the Watchdog peripheral. It is set by hard7 0 ware (watchdog reset) and cleared by software WDG (writing zero). 0 0 0 0 0 0 0
RF
Bits 7:1 = Reserved, must be kept cleared.
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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 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 each interrupt vector (see Table 6). The processing flow is shown in Figure 15 Figure 15. Interrupt Processing Flowchart
RESET PENDING INTERRUPT N Y TRAP 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
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 6. Interrupt Software Priority Levels
Interrupt software priority Level 0 (main) Level 1 Level 2 Level 3 (= interrupt disable) Level Low I1 1 0 0 1 I0 0 1 0 1
High
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 16 describes this decision process. Figure 16. Priority Decision Process
PENDING INTERRUPTS
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. 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 15. 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. 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. 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 (i.e. waiting for being serviced) will therefore be lost if the clear sequence is executed.
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 and TRAP 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 15). After stacking the PC, X, A and CC registers (except for RESET), the corresponding
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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 16. 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 17. Concurrent Interrupt Management
TRAP SOFTW ARE PRIORITY LEVEL IT2 IT1 IT4 IT3 IT0 I1 I0
7.4 CONCURRENT & NESTED MANAGEMENT The following Figure 17 and Figure 18 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 18. The interrupt hardware priority is given in this order from the lowest to the highest: MAIN, IT4, IT3, IT2, IT1, IT0. The software priority is given for each interrupt. Warning: A stack overflow may occur without notifying the software of the failure.
HARDWARE PRIORITY
TRAP 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 18. Nested Interrupt Management
TRAP
SOFTW ARE PRIORITY LEVEL
IT0
IT2
IT1
IT4
IT3
I1
I0
HARDWARE PRIORITY
TRAP 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 ISPR0
INTERRUPT SOFTWARE PRIORITY REGISTERS (ISPRX) Read/Write (bit 7:4 of ISPR3 are read only) Reset Value: 1111 1111 (FFh)
7 I1_3 I1_7 I0_3 I0_7 I1_2 I1_6 I0_2 I0_6 I1_1 I1_5 I0_1 I0_5 I0_9 I1_0 I1_4 I1_8 0 I0_0 I0_4 I0_8
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 0 1 I0 0 1 0 1
ISPR1 ISPR2 ISPR3
I1_11 I0_11 I1_10 I0_10 I1_9 1 1 1 1
I1_13 I0_13 I1_12 I0_12
High
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: 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 correspondance 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 can not 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, and TRAP vectors have no software priorities. When one is serviced, the I1 and I0 bits of the CC register are both set. Caution: If the I1_x and I0_x bits are modified while the interrupt x is executed the following behaviour 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 7. Dedicated Interrupt Instruction Set
Instruction HALT IR ET 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 8. Interrupt Mapping
Source Block RE SET TRAP 0 1 2 3 4 5 6 7 8 9 10 11 SPI T IME R A T IME R B SCI MCC/RTC ei0 ei1 e i2 e i3 Reset Software interrupt Not used Main clock controller time base interrupt External interrupt port A3..0 External interrupt port F2..0 External interrupt port B3..0 External interrupt port B7..4 Not used SPI peripheral interrupts TIMER A peripheral interrupts TIMER B peripheral interrupts SCI Peripheral interrupts Not used SPICSR T ASR T BSR SCIS R Lower Priority yes 1) no no no no no no no N/A MCCSR Higher Priority yes yes y es y es y es y es no no no no Register Label Priority Order Exit from HALT yes no Exit from ACTIVE HA LT y es no Address Vector FFFEh-FFFFh FFFCh-FFFDh FFFAh-FFFBh FFF8h-FFF9h FFF6h-FFF7h FFF4h-FFF5h FFF2h-FFF3h FFF0h-FFF1h FFEEh-FFE Fh FFECh-FFED h FFEAh-FFEB h FFE8h-FFE9h FFE6h-FFE7h FFE4h-FFE5h
N
Description
N/A
Note 1: Unexpected exit from HALT may occur when SPI is in slave mode. 7.6 EXTERNAL INTERRUPTS 7.6.1 I/O Port Interrupt Sensitivity The external interrupt sensitivity is controlled by the IPA, IPB and ISxx bits of the EICR register (Figure 19). This control allows to have up to 4 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 Falling and rising edge Falling edge and low level Rising edge and high level (only for ei0 and ei2) 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], IPA or IPB bits of the EICR.
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Figure 19. External Interrupt Control bits
PORT A3 INTERRUPT PAOR.3 PADDR.3 PA3
EICR IS20 IS21 ei0 INTERRUPT SOURCE
SENSITIVITY CONTROL
IPA BIT PORT F [2:0] INTERRUPTS PFOR.2 PFDDR.2 PF2 EICR IS20 IS21 PF2 PF1 PF0
SENSITIVITY CONTROL
ei1 INTERRUPT SOURCE
PORT B [3:0] INTERRUPTS PBOR.3 PBDDR.3 PB3
EICR IS10 IS11 PB3 PB2 PB1 PB0
SENSITIVITY CONTROL
ei2 INTERRUPT SOURCE
IPB BIT
PORT B [7:4] INTERRUPTS PBOR.7 PBDDR.7 PB7
EICR IS10 IS11 PB7 PB6 PB5 PB4
SENSITIVITY CONTROL
ei3 INTERRUPT SOURCE
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INTERRUPTS (Cont'd) 7.7 EXTERNAL INTERRUPT CONTROL REGISTER (EICR) Read / Write Reset Value: 0000 0000 (00h)
7 IS11 IS10 IPB I S21 I S20 IPA 0 0 0
Bit 4:3 = IS2[1:0] ei0 and ei1 sensitivity The interrupt sensitivity, defined using the IS2[1:0] bits, is applied to the following external interrupts:
- ei0 (port A3..0) Bit 7:6 = IS1[1:0] ei2 and ei3 sensitivity The interrupt sensitivity, defined using the IS1[1:0] bits, is applied to the following external interrupts: - ei2 (port B3..0)
External Interrupt Sensitivity IS11 IS10 IPB bit =0 0 0 1 1 0 1 0 1 Falling edge & low level Rising edge only Falling edge only IPB bit =1 Rising edge & high level Falling edge only Rising edge only 0 1 1 1 0 1 External Interrupt Sensitivity IS21 IS20 IPA bit =0 0 0 Falling edge & low level Rising edge only Falling edge only IPA bit =1 Rising edge & high level Falling edge only Rising edge only
Rising and falling edge
Rising and falling edge
- ei1 (port F2..0)
I S 21 IS20 0 0 1 0 1 External Interrupt Sensitivity Falling edge & low level Rising edge only Falling edge only Rising and falling edge
- ei3 (port B4)
IS11 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
0 1 1
These 2 bits can be written only when I1 and I0 of the CC register are both set to 1 (level 3). Bit 2 = IPA Interrupt polarity for port A This bit is used to invert the sensitivity of the port A [3:0] external interrupts. It can be set and cleared by software only when I1 and I0 of the CC register are both set to 1 (level 3). 0: No sensitivity inversion 1: Sensitivity inversion Bits 1:0 = Reserved, must always be kept cleared.
These 2 bits can be written only when I1 and I0 of the CC register are both set to 1 (level 3). Bit 5 = IPB Interrupt polarity for port B This bit is used to invert the sensitivity of the port B [3:0] external interrupts. It can be set and cleared by software only when I1 and I0 of the CC register are both set to 1 (level 3). 0: No sensitivity inversion 1: Sensitivity inversion
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INTERRUPTS (Cont'd) Table 9. Nested Interrupts Register Map and Reset Values
Address (Hex.) 0024h Register Label ISPR0 Reset Value ISPR1 Reset Value ISPR2 Reset Value ISPR3 Reset Value EICR Reset Value 7 ei1 I1_3 1 SP I 0025h I1_7 1 AVD 0026h I1_11 1 I0_11 1 I1_10 1 I0_7 1 I1_6 1 SCI I0_10 1 I0_6 1 I0_3 1 I1_2 1 6 5 ei0 I0_2 1 4 3 2 1 0
MCC + SI I1_1 I0_1 1 1 e i3 I1_5 I0_5 1 1 T IM ER B I1_9 I0_9 1 1 I1_13 1 IS20 0 I0_13 1 IPA 0
1 ei2
1
I1_4 I0_4 1 1 T IME R A I1_8 I0_8 1 1 I1_12 1 0 I0_12 1 0
0027h 0028h
1 IS11 0
1 IS10 0
1 IPB 0
1 IS21 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, four main power saving modes are implemented in the ST7 (see Figure 20): SLOW, WAIT (SLOW WAIT), ACTIVE HALT and 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 20. Power Saving Mode Transitions
High
fOSC2/2 fOSC2/4 f OSC2
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 when entering the WAIT mode while the device is already in SLOW mode. Figure 21. SLOW Mode Clock Transitions
RUN SLOW MCCS R WAIT SLOW WAIT ACTIVE HALT HALT Low PO WER CONS UMPTION
fCPU
fOSC2 CP1:0 SMS 00 01
NEW SLOW FREQUENCY REQUEST
NORMAL RUN MODE REQUEST
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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 22. Figure 22. WAIT Mode Flow-chart
OSCILLATOR PERIPHERALS CP U I[1:0] BITS ON ON OFF 10
WFI I N S T R U C T I O N
N RE SET N INTERRUP T Y OSCILLATOR PERIPHERALS CP U I[1:0] BITS ON OFF ON 10 Y
256 OR 4096 CPU CLOCK CYCLE DELAY
OSCILLATOR ON PERIPHERALS ON CP U ON I[1:0] BITS XX 1)
FETC H RES ET VEC TOR OR SERVICE INTERRUPT
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 ACTIVE-HALT AND HALT MODES ACTIVE-HALT and HALT modes are the two lowest power consumption modes of the MCU. They are both entered by executing the `HALT' instruction. The decision to enter either in ACTIVE-HALT or HALT mode is given by the MCC/RTC interrupt enable flag (OIE bit in MCCSR register).
MCCSR O I E bi t 0 1 Power Saving Mode entered when HALT instruction is executed HALT mode ACTIVE-HALT mode
pending on option byte). Otherwise, the ST7 enters HALT mode for the remaining tDELAY period. Figure 23. ACTIVE-HALT Timing Overview
RUN ACTIVE 256 OR 4096 CPU HA LT CYCLE DELAY 1) RESET OR INTER RUPT RUN
HA LT IN STRUCTION [MCCS R.OIE=1]
FE TCH VECTOR
Figure 24. ACTIVE-HALT Mode Flow-chart 8.4.1 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 the OIE bit of the Main Clock Controller Status register (MCCSR) is set (see Section 10.2 on page 53 for more details on the MCCSR register). The MCU can exit ACTIVE-HALT mode on reception of either an MCC/RTC interrupt, a specific interrupt (see Table 8, "Interrupt Mapping," on page 33) or a RESET. When exiting ACTIVEHALT mode by means of an interrupt, no 256 or 4096 CPU cycle delay occurs. The CPU resumes operation by servicing the interrupt or by fetching the reset vector which woke it up (see Figure 24). When entering ACTIVE-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 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 ACTIVEHALT mode is provided by the oscillator interrupt. Note: As soon as the interrupt capability of one of the oscillators is selected (MCCSR.OIE bit set), entering ACTIVE-HALT mode 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. CAUTION: When exiting ACTIVE-HALT mode following an interrupt, OIE bit of MCCSR register must not be cleared before tDELAY after the interrupt occurs (tDELAY = 256 or 4096 tCPU delay deHALT INSTRUCTION (MCCSR.OIE=1) OSCILLATOR PERIPHERALS 2) CPU I[1:0] BITS N N ON OFF OFF 10
RESET Y
INTERRUPT 3) Y
OSCILLATOR PERIPHERALS CPU I[1:0] BITS
ON OFF ON XX 4)
256 OR 4096 CPU CLOCK CYCLE DELAY OSCILLATOR PERIPHERALS CPU I[1:0] BITS ON ON ON XX 4)
FETCH RESET VECTOR OR SERVICE INTERRUPT
Notes: 1. This delay occurs only if the MCU exits ACTIVEHALT mode by means of a RESET. 2. Peripheral clocked with an external clock source can still be active. 3. Only the MCC/RTC interrupt and some specific interrupts can exit the MCU from ACTIVE-HALT mode (such as external interrupt). Refer to Table 8, "Interrupt Mapping," on page 33 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 restored when the CC register is popped.
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POWER SAVING MODES (Cont'd) 8.4.2 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 53 for more details on the MCCSR register). The MCU can exit HALT mode on reception of either a specific interrupt (see Table 8, "Interrupt Mapping," on page 33) 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 14.1 on page 145) for more details. Figure 25. HALT Timing Overview
RUN HA LT 256 OR 4096 CPU CYCLE DELAY RESET OR INTER RUPT FE TCH VECTOR RUN FETC H RES ET VEC TOR OR SERVICE INTERRUPT
Figure 26. HALT Mode Flow-chart
H AL T INSTRUCTION (MCCSR.OIE=0) ENABLE W D GH A L T 1 ) 1 W ATCHDO G RE SET OSCILLATOR OFF PERIPHERALS 2) OFF CP U OFF I[1:0] BITS 10 0 W ATCHDOG DISABLE
N RE SET N Y INTERRUPT 3) Y OSCILLATOR ON PERIPHERALS OFF CP U ON I[1:0] BITS XX 4) 256 OR 4096 CPU CLOCK C YCL E DE LAY OSCILLATOR ON PERIPHERALS ON CP U ON I[1:0] BITS XX 4)
HA LT IN STRUCTION [MCCS R.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 8, "Interrupt Mapping," on page 33 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) 8.4.2.1 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).
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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 2 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 27 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 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 27. I/O Port General Block Diagram
REGISTER ACCESS ALTERNATE OUTPUT 1 0 ALTERNATE ENABLE DR
VDD
P-BUFFER (see table below) PULL-UP (see table below) VDD
DDR P U LL-UP C ON D I T I O N If implemented OR SEL N-BUFFER DDR SEL C MOS SCHMITT TRIGGER AN ALOG INPUT DIODES (see table below) PAD
OR
E XTERNAL IN TERR UPT SOURCE (eix)
Table 10. 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 t o VS S
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 11. 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 O UTPUT 2 )
VDD RPU
DR REGISTER ACCESS
PAD
DR REGISTER
R/W
DATA BUS
ALTERNATE ENABLE
ALTERNATE OUTPUT
P U S H - P U L L OU T P U T 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 28 Other transitions are potentially risky and should be avoided, since they are likely to present unwanted side-effects such as spurious interrupt generation.
Figure 28. 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 Yes Exit from Halt Yes
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I/O PORTS (Cont'd) 9.5.1 I/O Port Implementation The I/O port register configurations are summarised as follows. Standard Ports PA5:4, PC7:0, PD5:0, PE1:0, PF7:6, 4
MODE floating input pull-up input open drain output push-pull output D DR 0 0 1 1 OR 0 1 0 1
PA3, PB3, PF2 (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
True Open Drain Ports PA7:6
MODE floating input open drain (high sink ports) DDR 0 1
Interrupt Ports PB4, PB2:0, PF1:0 (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
Table 12. Port Configuration
Port Pin name
PA7:6 PA5:4 PA3 PB3 PB4, PB2:0 PC7:0 PD5:0 PE1:0 PF7:6, 4 PF2 PF1:0
Input OR = 0
floating floating floating floating floating floating floating floating floating floating floating pull-up floating interrupt floating interrupt pull-up interrupt pull-up pull-up pull-up pull-up floating interrupt pull-up interrupt
Output OR = 1 OR = 0 OR = 1
true open-drain open drain push-pull open drain push-pull open drain push-pull open drain push-pull open drain push-pull open drain push-pull open drain push-pull open drain push-pull open drain push-pull open drain push-pull
Port A
Port B Port C Port D Port E Port F
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I/O PORTS (Cont'd) Table 13. 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 I/O 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 WATCHDOG TIMER (WDG) 10.1.1 Introduction The Watchdog timer 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 counter's contents before the T6 bit becomes cleared. 10.1.2 Main Features Programmable free-running downcounter Programmable reset Reset (if watchdog activated) when the T6 bit reaches zero Optional reset on HALT instruction (configurable by option byte) Hardware Watchdog selectable by option byte 10.1.3 Functional Description The counter value stored in the Watchdog Control register (WDGCR 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 timer (bits T[6:0]) rolls over from 40h to 3Fh (T6 becomes cleared), it initiates a reset cycle pulling low the reset pin for typically 30s. The application program must write in the WDGCR register at regular intervals during normal operation to prevent an MCU reset. This downcounter is free-running: it counts down even if the watchdog is disabled. The value to be stored in the WDGCR register must be between FFh and C0h: The WDGA bit is set (watchdog enabled) The T6 bit is 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 30. 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 31). Following a reset, the watchdog is disabled. Once activated it cannot be disabled, except by a reset. The T6 bit can be used to generate a software reset (the WDGA bit is set and the T6 bit is cleared). If the watchdog is activated, the HALT instruction will generate a Reset.
Figure 29. Watchdog Block Diagram
RESE T
fOSC2 MCC/RTC
WATCHDOG CONTROL REGISTER (WDGCR) DIV 64 WDG A T6 T5 T4 T3 T2 T1 T0
6-BIT DOWNCOUNTER (CNT)
12-BIT MCC RTC COUNTER M SB
11 65
LSB
0
TB[1:0] bits (M CCSR Register)
WDG PRESCALER DIV 4
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WATCHDOG TIMER (Cont'd) 10.1.4 How to Program the Watchdog Timeout Figure 30 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 30. Approximate Timeout Duration 3F 38 30
more precision is needed, use the formulae in Figure 31. 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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WATCHDOG TIMER (Cont'd) Figure 31. 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
THEN
t m i n = t m i n 0 + 16384 × C N T × t o s c 2 × to 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 calculate the maximum Watchdog Timeout (tmax):
S IF C N T M------B ---- --4
T H E N 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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WATCHDOG TIMER (Cont'd) 10.1.5 Low Power Modes Mode SLOW WAIT Description No effect on Watchdog. No effect on Watchdog.
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. If an external interrupt is received, 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 10.1.7 below. A reset is generated. 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.
0
0
HALT
0
1
1
x
10.1.6 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 d e s c r i p t io n . 10.1.7 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. 10.1.8 Interrupts None.
10.1.9 Register Description CONTROL REGISTER (WDGCR) Read / Write Reset Value: 0111 1111 (7Fh)
7 WDG A T6 T5 T4 T3 T2 T1 0 T0
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. Bit 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).
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Table 14. Watchdog Timer Register Map and Reset Values
Address (Hex.) 002Ah Register Label W D GC R Reset Value 7 WD GA 0 6 T6 1 5 T5 1 4 T4 1 3 T3 1 2 T2 1 1 T1 1 0 T0 1
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10.2 MAIN CLOCK CONTROLLER WITH REAL TIME CLOCK AND BEEPER (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. CAUTION: When selected, the clock out pin suspends the clock during ACTIVE-HALT mode. 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 four 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 8.4 ACTIVE-HALT AND HALT MODES for more details. 10.2.4 Beeper The beep function is controlled by the MCCBCR register. It can output three selectable frequencies on the BEEP pin (I/O port alternate function).
Figure 32. Main Clock Controller (MCC/RTC) Block Diagram
BC1 BC0 MCCBCR BEEP BEEP SIGNAL SELECTION MCO
DIV 64
12-BIT MCC RTC COUNTER
TO WATCHDOG TIMER
MCO CP1 CP0 SMS TB1 TB0 OIE MCCSR fOSC2 DIV 2, 4, 8, 16
OIF MCC/RTC INTERRUPT
1 0
fCPU
CPU CLOCK TO CPU AND PERIPHERALS
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MAIN CLOCK CONTROLLER WITH REAL TIME CLOCK (Cont'd) 10.2.5 Low Power Modes Bit 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 exit conditioned by the setting of the SMS bit. These from WAIT mode. two bits are set and cleared by software
A C TIVEH AL T No effect on MCC/RTC counter (OIE bit is set), the registers are frozen. MCC/RTC interrupt cause the device to exit from ACTIVE-HALT mode. MCC/RTC counter and registers are frozen. MCC/RTC operation resumes when the 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
H AL T
10.2.6 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 Ye s Exit from Halt No 1 )
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 AND BEEPER (MCC/RTC) for more details . Bit 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 =4MHz fOSC2=8MHz 16000 4ms 8ms 20ms 50ms 2ms 4ms 10m s 25m s 32000 80000 20 0 0 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 mode.
10.2.7 Register Description MCC CONTROL/STATUS REGISTER (MCCSR) Read / Write Reset Value: 0000 0000 (00h)
7 MCO C P1 CP0 SM S TB1 T B0 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 ACTIVEHALT 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 PF0 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 (fCPU on I/O port) Note: To reduce power consumption, the MCO function is not active in ACTIVE-HALT mode.
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MAIN CLOCK CONTROLLER WITH REAL TIME CLOCK (Cont'd) MCC BEEP CONTROL REGISTER (MCCBCR) Bit 0 = OIF Oscillator interrupt flag This bit is set by hardware and cleared by software Read / Write reading the MCCSR register. It indicates when set Reset Value: 0000 0000 (00h) that the main oscillator has reached the selected elapsed time (TB1:0). 7 0 0: Timeout not reached 1: Timeout reached 0 0 0 0 0 0 BC1 BC0 CAUTION: The BRES and BSET instructions must not be used on the MCCSR register to avoid Bit 7:2 = Reserved, must be kept cleared. unintentionally clearing the OIF bit. Bit 1:0 = BC[1:0] Beep control These 2 bits select the PF1 pin beep capability.
BC1 0 0 1 1 B C0 0 1 0 1 ~2-KHz ~1- KHz ~500-Hz Beep mode with fOSC2=8MHz Off Output Beep signal ~50% duty cycle
The beep output signal is available in ACTIVEHALT mode but has to be disabled to reduce the consumption. Table 15. Main Clock Controller Register Map and Reset Values
Address (Hex.) 002Ch 002Dh Register Label M CCSR Reset Value M CCBCR Reset Value 7 MC O 0 0 6 CP1 0 0 5 CP0 0 0 4 SM S 0 0 3 TB1 0 0 2 TB0 0 0 1 OIE 0 BC1 0 0 OIF 0 BC0 0
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