23.9 Setup for PWM Operation Using PWMx Output Pins

Follow the next steps when configuring the module for PWM operation using the PWMx pins:

  1. Disable the PWMx pin output driver(s) by setting the associated TRIS bit(s).
  2. Clear the PWMxCON register.
  3. Load the T2PR register with the PWM period value.
  4. Load the PWMxDCH register and bits [7:6] of the PWMxDCL register with the PWM duty cycle value.
  5. Configure and start Timer2:
    • Clear the TMR2IF Interrupt Flag bit of the PIRx register.(1)
    • Select the timer clock source to be as FOSC/4 using the T2CLKCON register. This is required for correct operation of the PWM module.
    • Configure the CKPS bits of the T2CON register with the Timer2 prescale value.
    • Enable Timer2 by setting the ON bit of the T2CON register.
  6. Enable the PWM output pin and wait until Timer2 overflows; the TMR2IF bit of the PIRx register is set.(2)
  7. Enable the PWMx pin output driver(s) by clearing the associated TRIS bit(s) and setting the desired pin PPS control bits.
  8. Configure the PWM module by loading the PWMxCON register with the appropriate values.
Note:
  1. To send a complete duty cycle and period on the first PWM output, the above steps must be followed in the given order. If it is not critical to start with a complete PWM signal, then move step 8 to replace step 4.
  2. For operation with other peripherals only, disable PWMx pin outputs.