I don't understand what you mean by do PWM on incoming signal ?
Do you want to simply synchronize an internally generated PWM with the
incoming waveform ? or are you wanting to measure the duty cycle of the
incoming waveform and use the result to modify the output waveform ?

What micro are you using ? Several already have a couple of PWM outputs
built in, otherwise you can use a timer.

Regards
David Huisman

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu