STM32WL55: IPCC wake up CPU2 from STOP mode? Workarounds?

[Pieter Conradie]

Hi there!

If I interpret table 45 on p. 247 of the reference manual correctly, then the IPCC interrupt is not able to wake up a CPU from STOP mode:

Am I correct in my interpretation? If so, is there any other way for CPU1 to wake up CPU2 from STOP mode to signal that there is a message waiting? One way I can think of is connecting two GPIO pins so that CPU1 can generate an external interrupt to CPU2 but that feels like such a waste of resources :(

Thanks in advance,

Pieter

[Pieter Conradie]

ST support helped me on this. For other people also looking for a solution, this is it:

On CPU1:

// Enable IPCC CPU1 Wake up interrupt
LL_EXTI_EnableIT_32_63(LL_EXTI_LINE_36);

On CPU2:

// Enable IPCC CPU2 Wake up interrupt
LL_C2_EXTI_EnableIT_32_63(LL_EXTI_LINE_37);

See Reference Manual "16.3.1 EXTI wake-up interrupt list":

Best regards,

Pieter

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