Very low power pulse generation switch-based circuit for MCU wake-up
simulate this circuit &ndash; Schematic created using CircuitLab


the bounce time must be less than T, otherwise increase T


Rev 1


Added buffer hinted by Elliot.  (chose Schmitt Nand)
corrected polarity for negative logic resets.
added Power on Reset  (POR), low leakage Si diode.
added Watch Dog Timer reset input (WDT) (useful)


For more wisdom, read what microchip say...

http://ww1.microchip.com/downloads/en/DeviceDoc/31003a.pdf