I have a reset signal which should be triggered by a falling flank from 5V to 0 volt. This flank should generate a low pulse (5V -> 0V -> 5V). This can be done by just adding a capacitor and a pull-up. However since I also use the RESET pin for debug wire I can not have a capacitor. So what I need:
Input: falling flank from 5V to 0 volt Output: not conected -> 0V -> not conected
Outside this circuit I will have a 20k pull-up to the RESET pin. The important part is that there may be no low pass filtering by caps on the reset pin since that will afect the debug wire.
How do a low cost circuit look for this?