26.9 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 TxPR 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 Timerx:
    • Clear the TMRxIF Interrupt Flag bit of the PIRx register.(1)
    • Select the timer clock source to be as FOSC/4 using the TxCLKCON register. This is required for correct operation of the PWM module.
    • Configure the CKPS bits of the TxCON register with the Timerx prescale value.
    • Enable Timerx by setting the ON bit of the TxCON register.
  6. Enable the PWM output pin and wait until Timerx overflows; the TMRxIF 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.