Introduction
The purpose of this application note is to guide the end-user on the IBIS (I/O buffer information specification) models of STMicroelectronics STM32 32-bit Arm® Cortex® MCUs and MPUs. It also gives guidance on the use of external peripherals to perform board-level simulations with the HyperLynx® SI (signal integrity) software, to address SI issues.
As a concrete example, this application uses STM32F7 Series and STM32MP15 Series devices. All of the information and conclusions can be extrapolated to any STM32 32-bit Arm® Cortex® MCU or MPU.
As the signal speed increases, SI and EMC (electromagnetic compliance) become issues. These issues are detectable by test equipment, as a signal degradation: overshoot, undershoot, ringing, crosstalk, or timing delay.
One possible cause of signal degradation is a poor board design that fails CE/FCC certification. Another potential cause is timing violations between the IC (integrated circuit) drivers and the receiver. Emphasis must be put on getting the design right the first time to avoid costly redesign, and multiple successive layouts and prototypes. Therefore, performing an SI simulation is very important before designing a prototype.
