Hi,
As far as I know there are no such features in any PIC16 or 18.

If the purpose is to stop the PWM-module (overcurrent for example) you can use the FAULT-inputs but unfortunately the 4431 doesn't have an internal comparator so you'll need an external one. Use a spare channel on the PWM module or a "standard" CCP-module to output a PWM, lowpass filter it and run it to the external comparator.

The Fault input will stop the PWM thru hardware which gives you the fastest possible latency. You could then check the pin in your main loop to run any other code that needs to be run.

/Henrik.