PIC16LF1526 Datasheet, PDF (193/354 Pages) Microchip Technology – 64-Pin Flash Microcontrollers with nanoWatt XLP Technology

20.3.2 SETUP FOR PWM OPERATION
The following steps should be taken when configuring
the CCP module for standard PWM operation:
1. Disable the CCPx pin output driver by setting the
associated TRIS bit.
2. Load the PRx register with the PWM period
value.
3. Configure the CCP module for the PWM mode
by loading the CCPxCON register with the
appropriate values.
4. Load the CCPRxL register and the DCxBx bits
of the CCPxCON register, with the PWM duty
cycle value.
5. Configure and start Timer2/4/6/8/10:
• Select the Timer2/4/6/8/10 resource to be
used for PWM generation by setting the
CxTSEL<1:0> bits in the CCPTMRSx
register.
• Clear the TMRxIF interrupt flag bit of the
PIRx register. See Note below.
• Configure the TxCKPS bits of the TxCON
register with the Timer prescale value.
• Enable the Timer by setting the TMRxON
bit of the TxCON register.
6. Enable PWM output pin:
• Wait until the Timer overflows and the
TMRxIF bit of the PIRx register is set. See
Note below.
• Enable the CCPx pin output driver by clear-
ing the associated TRIS bit.
Note:
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.
20.3.3 TIMER2/4/6/8/10 TIMER RESOURCE
The PWM standard mode makes use of one of the 8-bit
Timer2/4/6/8/10 timer resources to specify the PWM
period.
Configuring the CxTSEL<1:0> bits in the CCPTMRSx
register selects which Timer2/4/6/8/10 timer is used.
See Table 20-6 for CCPx PWM Timer2/4/6/8/10
resources.
PIC16(L)F1526/27
20.3.4 PWM PERIOD
The PWM period is specified by the PRx register of
Timer2/4/6/8/10. The PWM period can be calculated
using the formula of Equation 20-1.
EQUATION 20-1: PWM PERIOD
PWM Period = PRx + 1  4  TOSC 
(TMRx Prescale Value)
Note 1: TOSC = 1/FOSC
When TMRx is equal to PRx, the following three events
occur on the next increment cycle:
• TMRx 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 latched from CCPRxL into
CCPRxH.
Note:
The Timer postscaler (see Section 19.1
“Timer2/4/6/8/10 Operation” is not used
in the determination of the PWM
frequency.
 2011 Microchip Technology Inc.
Preliminary
DS41458A-page 193