PIC16F722AT-ISS Datasheet, PDF (129/286 Pages) Microchip Technology – 28-Pin Flash Microcontrollers with nanoWatt XLP Technology

15.3 PWM Mode
The PWM mode generates a Pulse-Width Modulated
signal on the CCPx pin. The duty cycle, period and
resolution are determined by the following registers:
• PR2
• T2CON
• CCPRxL
• CCPxCON
In Pulse-Width Modulation (PWM) mode, the CCP
module produces up to a 10-bit resolution PWM output
on the CCPx pin.
Figure 15-3 shows a simplified block diagram of PWM
operation.
Figure 15-4 shows a typical waveform of the PWM
signal.
For a step-by-step procedure on how to set up the CCP
module for PWM operation, refer to Section 15.3.8
“Setup for PWM Operation”.
FIGURE 15-3:
SIMPLIFIED PWM BLOCK
DIAGRAM
Duty Cycle Registers
CCPRxL
CCPxCON<5:4>
PIC16(L)F722A/723A
The PWM output (Figure 15-4) has a time base
(period) and a time that the output stays high (duty
cycle).
FIGURE 15-4:
Period
CCP PWM OUTPUT
Pulse Width
TMR2 = 0
TMR2 = PR2
TMR2 = CCPRxL:CCPxCON<5:4>
15.3.1 CCPX PIN CONFIGURATION
In PWM mode, the CCPx pin is multiplexed with the
PORT data latch. The user must configure the CCPx
pin as an output by clearing the associated TRIS bit.
Either RC1 or RB3 can be selected as the CCP2 pin.
Refer to Section 6.1 “Alternate Pin Function” for
more information.
Note: Clearing the CCPxCON register will
relinquish CCPx control of the CCPx pin.
CCPRxH⁽²⁾ (Slave)
Comparator
RQ
CCPx
TMR2
(1)
S
TRIS
Comparator
PR2
Clear Timer2,
toggle CCPx pin and
latch duty cycle
Note 1:
2:
The 8-bit timer TMR2 register is concatenated
with the 2-bit internal system clock (FOSC), or
2 bits of the prescaler, to create the 10-bit time
base.
In PWM mode, CCPRxH is a read-only register.
 2010-2012 Microchip Technology Inc.
DS41417B-page 129