Multiple Frequency PWM's

ccooper · Guest

With respect to the PIC18Fxx2x data sheet "CCP and TIMER interconnect Configurations". I am wondering how to program 2 independent PWMs WITH 2 independent frequencies and pulse widths and I still need a timer with a 16bit prescaler left over. How do I specify which configuration I need in CCS?

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

What's the exact part number of your PIC ?

Mark · Joined: 07 Sep 2003 Posts: 2838 Location: Atlanta, GA

You can also use the CCP module in compare mode to generate the PWMs. You just alternate between a low time and a high time or with enough CCP's you can use one to turn on and another to turn off.

ccooper · Joined: 21 Jul 2005 Posts: 1

I am using a PIC18F6621, but they all look about alike except some have only CCP and some are both CCP & ECCP. This CCP Module and Timer resouces figure is so confusing. These PICs have PR2 and PR4, but can you use both with seperate CCP (or ECCP if you have them) modules at the same to operate at different freqencies? Does "or" in the Timer resource table mean "xor" or "and/or" ? Even if I get the Microchip business straight - How do I allocate specifice timer resources for a particular individual CCP's in CCS?
Also is there a ap note that deals with using CCP's w/o PWM to generate PWM? I can dig into the Capture and Compare, but it would save time if I could see it first. Thanks