2021-07-19 01:58 AM
Hi. I am using an STM32L073 based nucleo board. There are 2 external wakeup pins configured on PA0 and PC13 in this board which can be used to wake the device out of standby.
If I write code to configure these two wake up Pins to wake up from the standby mode individually, the system works flawlessly. ie, in 2 separate runs (individually), if I set the corresponding bits EWUP1 (PA0) and EWUP2 (PC13) of PWR_CSR register and enter into Standby mode, whenever I perform a low to high transition on the corresponding pin, the system comes out of standby.
However, if both these are enable together simultaneously in the same code
(PWR_CSR|= (EWUP1_SET|EWUP2_SET) ) and I enter standby, only the EWUP2 (PC13) wakes the microcontroller up, not EWUP1 (PA0), even though ithis it is set before entering into standby. I have tried a number of ways, but it does not seem to be working.
Individually however, PA0 and PC13 works. Can somebody throw some light on what may be the reason?