I have recently came upon a strange problem while using the S12ZVL64 MCU:
While going to sleep mode from an under voltage situation the MCU will never wake up if the voltage returns to normal values.
This issue only happens on one project that has a bigger capacitor on the supply line(220uA), other parts work fine with the same code.
The way I reproduce it is to simply switch off the power supply. If I switch on the power supply until the capacitor is not empty the MCU never wakes up.
The code uses the low voltage interrupt to trigger the transition to STOP mode. I dont think the code is to blame because other parts with smaller capacitor work fine with same code, seems more like a timing issue inside the MCU
Do you have any hint for me ? I checked the errata but no mention of this.