2020-03-26 10:28 AM
I'm writing some kind of safe system clock configuration and a bit paranoid. Setup starts with enabling HSE and after stable, it is used as a source for PLL. If HSE fails my program switching to HSI and enables PLL ones again with HSI as a source and different multipliers to get the same SYSCLK frequency. I would like to implement control theory algorithms, so I need to work in real-time and I want to know if it is possible, that PLL will fail while MCU, in general, won't. Because if so I will need to have a function that will set up all time-related stuff with new values if PLL won't start, cause HSI and PLL frequencies are in general different i need my system to have interrupts with the constant time.
Question is in general to any stm32 MCU but in the project I use stm32g071cbu.
2020-03-26 10:42 AM
If the PLL goes, then the only way out is an IWDG reset, as nothing else would be clocked.