[quote user="CaEngineer"]Excuse me I have heard about SVM: Supply Voltage Supervisor but not SVMh! With interrupt? Can you please be more specific?[/quote]
Wel.. I missed that you use 4-series. SVM (unfortunately for you) is present on 5-series.
This still leaves comparator option as voltage detector for you. Well. If you have big enough power supply storage capacitors, you can use ADC too. Or just external power supply supervisor IC connected to IO pin with pin interrupt enabled.
