Potential race before entering low power state on STM32

[dflogeras]

Hi,

I often use the low power modes on STM32, and get woken up by a GPIO pin. It just occurred to me that there would be a race if the pin I am waiting for has already changed state before going into a low power state.

For instance,
if( palReadPad( ... )) {
PWR->CR |= ....;
...
__WFI();
}

In the unlikely event that pin changes state before __WFI() is called, I will miss the event. Is there a sane way to mitigate this?

[Giovanni]

An external delay added to the line maybe.

Giovanni

[alexblack]

Hi.
Use event instead of interrupt. Event will set pending bit, which may cleared only by WFE instruction.