WB_PWMX - Initialization

The following steps outline the basic procedure to initialize the WB_PWMX Controller ready for operation. You will need to re-initialize the Controller after each external reset.

• Write the resolution control bits (mod1 and mod0) in the Control register (PWCON.5 and PWCON.4) to set up the resolution you require. This should be done before writing the required pulse width to the PWMRG registers.

• Write the required value for the pulse width to the PWMRG register (upper 6 bits written to the PWMRGHI address and low byte written to the PWMRGLO address).

• Write the required low-order byte of the pre-scale value to the PWPLO register.

• Write the required high-order byte of the pre-scale value to the PWPHI register.

• Write the necessary value to the Control register (PWCON) to enable the Controller and interrupts. For example, to enable the controller and all interrupts, the following bits must be set:
   
  • pwen (PWCON.0) – enable the Controller
  • pien (PWCON.1) – global interrupt enable
  • prie (PWCON.2) – enable pre-scaler counter interrupt
  • pwie (PWCON.3) – enable PWM counter interrupt.

This would be performed using a read-modify-write operation, since you have already set the resolution mode bits in the Control register.