4.3 PWM Period

The PWM period is specified by the T2PR register of Timer2. The PWM period can be calculated using the formula in Equation 4-1.

Equation 4-1. PWM Period
P W M ⁢   P e r i o d = [ ( T 2 P R   +   1 ) ] • 4 • T O S C • ( T M R 2 ⁢     Pr e s c a l e ⁢     V a l u e ) ⁢
w h e r e :
T O S C ⁢     ⁢ =     1 F O S C ⁢

When T2TMR is equal to T2PR, the following three events occur on the next increment event:

  • T2TMR is cleared.
  • The CCPx pin is set. (Exception: If the PWM duty cycle = 0%, the pin will not be set.)
  • The PWM duty cycle is transferred from the CCPRx register into a 10-bit buffer.
Important: The Timer postscaler is not used in the determination of the PWM frequency.