What is best way to detect if a pulse occured on input pin while mcu was in stop mode? I don't want pulse to wake up the mcu.
Add an external counter.
The MCU in question is STM32L151xC and pin is PC13. I think it can't have an external counter. This pin has an additional function RTC_TAMP1. I'm currently finding out if that could be utilized in a such way.
External, as in not on the micro at all.
The alternative is to configure the pin as an EXTI, wakeup briefly and go back to sleep immediately, but you've indicated you don't want to do that.
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