interrupt duration

if you talk about a pio, the external signal must be active for some clock cycles (don't know

exactly how much) to get sampled.

if you talk about a user component:

that's tthe way I do it:

in a user component, I have a bit in a register (flipflop) which is set to generate

an interrupt (signal irq);

in the interrupt service routine, I clear this bit by writing to the irq-register of

the component;

so irq signal of the user component stays active until it's service routine is called.