I am using STM32F042F6 uC. I am not sure why this HAL_PWR_EnterSTANDBYMode() does not put the uC to sleep mode. But the odd thing is in certain condition, it does go the Standby mode, but in some other boards, the uC does not go to standby mode.
I would think this function is unconditionally put the uC to Standby mode. Is there any condition in which the uC cannot be put into Standby mode? Why would in some condition I can put uC in standby and in some I could not?