STM32U575 Watchdog Mechanism - ST bootloader, debugging & logging WD resets events

[RLanz.2]

Hi 
We want to use STM32U575 Watchdog Mechanism in our operational FW, but have the following concerns:

1. Can MCU ST Bootloader kick the WD in general, and especially during FOTA, when it is busy writing/reading to flash the new FW to update or during its execution prior to jumping to the FW?

2. How can we maintain debug capabilities - no resets during debugging - is there a debug settings taking care of it?

3. How can we log events of resets which happened due to WD - can the RCC be examined during startup to analyze if the reset was due to a watchdog?

4. How can we log events of resets which happened due to WD - can an IWDG interrupt be used and how?

5. When is best to initialize and activate the watchdog during the FW startup - especially when we have some long wait (seconds) during the FW startup to overcome some initialization problem we currently face?

6. Can the watchdog setting be changed or disabled AFTER it was already activated?

7. What are the main considerations to choose to work in Software or hardware watchdog mode?

Thanks in advance for any relevant info.

[Saket_Om]

Hello @RLanz.2 

In general, the embedded bootloader reloads the IWDG in the sections of code that take some time for processing to avoid that the IWDG interrupts bootloader execution.

Other than that, nothing is done and there is no specific case for FOTA.

Only the IWDG is reloaded, other WD are not reloaded.