Some PIC microcontrollers have a CCP (Capture Compare PWM) function.

Each has the following functions.

1. Capture function
   - Measure the time of the pulse period by capturing the input pulse for each edge and taking the difference
   
   
2. Compare function
   - Generate an interrupt when the value of the timer counter (TMRc) matches the value of the compare register (CCPRx)
   
   
3. PWM output function
   - PWM output is possible in combination with timer function

Schematic block diagram of CCP PWM operation

For details, refer to the data sheet for each model number.