RTC timed wakeup from STANDBY v STOP0

[EC.3]

Hello,

I ran the STM32CubeU5\Projects\NUCLEO-U575ZI-Q\Examples_LL\RTC\RTC_ExitStandbyWithWakeUpTimer_Init application, which worked as described in its README.md. After changing the low power mode from STANDBY to STOP0, the RTC interrupt no longer fired and so it never transitioned out of STOP0. (I'm aware that since the example uses STANDBY that it actually resets after exiting rather than simply resuming, but this is clearly not getting to that point.)

Is there a simple explanation for this? I have a different HAL-based RTC timed wakeup from STOP0 app that works, and this example is LL-based, but it seems like that shouldn't matter.

[Issamos]

Hello @EC.3 

Can you add your code (after migration to stop0 mode) here so that our community members and experts can have a clearer idea about the issue.

Best regards.

II

[EC.3]

Hello @Issamos 

Here's the code. My STOP0-related changes are associated with the USE_STOP0 macro. Other changes against the original example were just using a U585 *.s and *.ld file, along with LED1 pin mapping and disabling use of SMPS.

[EC.3]

Hello @Issamos,

Thought I'd check in to see if there are any takers on this, now that I am revisiting it myself. I'm attaching just the main.c this time - and I switched to using STOP2 rather than STOP0 but same result - it doesn't wake up.

Thanks

[EC.3 · Accepted solution]

I was pointed to STM32CubeU5\Projects\NUCLEO-U575ZI-Q\Examples\PWR\PWR_LPMODE_RTC as another reference example. After integrating what it did into my own IOC-based project for U585, it seemed to work.