Setup for PWM Operation to Other Device Peripherals

The following steps should be taken when configuring the module for PWM operation to be used by other device peripherals:

  1. 1.Disable the PWMx pin output driver(s) by setting the associated TRIS bit(s).
  2. 2.Clear the PWMxCON register.
  3. 3.Load the T2PR register with the PWM period value.
  4. 4.Load the PWMxDCH register and bits <7:6> of the PWMxDCL register with the PWM duty cycle value.
  5. 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 TxCLKCON register. This is required for correct operation of the PWM module.
    • Configure the T2CKPS bits of the T2CON register with the Timer2 prescale value.
    • Enable Timer2 by setting the T2ON bit of the T2CON register.
  6. 6.Wait until Timer2 overflows, TMR2IF bit of the PIRx register is set.(1)
  7. 7.Configure the PWM module by loading the PWMxCON register with the appropriate values.
  1. 1.In order to send a complete duty cycle and period on the first PWM output, the above steps must be included in the setup sequence. If it is not critical to start with a complete PWM signal on the first output, then step 6 may be ignored.