how long should interrupting signal last? I want to apply the interruption of a program with a RISING signal from a pin. How long should the signal rise to be considered as the interruption?
If edge or toggle interrupt is selected, pulses that last longer than one clock period will generate an interrupt. Shorter pulses are not recommended to generate an interrupt.


Source (page 91, chapter 17.2.1 "External Interrupt Control Register A")