Datasheet

PIC16F716
DS41206B-page 52 © 2007 Microchip Technology Inc.
8.3 PWM Mode
The PWM mode generates a Pulse-Width Modulated
signal on the CCP1 pin. The duty cycle, period and
resolution are determined by the following registers:
•PR2
•T2CON
• CCPR1L
• CCP1CON
In Pulse-Width Modulation (PWM) mode, the CCP
module produces up to a 10-bit resolution PWM output
on the CCP1 pin. Since the CCP1 pin is multiplexed
with the PORT data latch, the TRIS for that pin must be
cleared to enable the CCP1 pin output driver.
Figure 8-3 shows a simplified block diagram of PWM
operation.
Figure 8-4 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, see Section 8.3.7 “Setup
for PWM Operation”.
FIGURE 8-3: SIMPLIFIED PWM BLOCK
DIAGRAM
The PWM output (Figure 8-4) has a time base
(period) and a time that the output stays high (duty
cycle).
FIGURE 8-4: CCP PWM OUTPUT
Note: Clearing the CCP1CON register will
relinquish CCP1 control of the CCP1 pin.
CCPR1L
CCPR1H
(2)
(Slave)
Comparator
TMR2
PR2
(1)
RQ
S
Duty Cycle Registers
CCP1CON<5:4>
Clear Timer2,
toggle CCP1 pin and
latch duty cycle
Note 1: The 8-bit timer TMR2 register is concatenated
with the 2-bit internal system clock (F
OSC), or
2 bits of the prescaler, to create the 10-bit time
base.
2: In PWM mode, CCPR1H is a read-only register.
TRIS
CCP1
Comparator
Period
Pulse Width
TMR2 = 0
TMR2 = CCPR1L:CCP1CON<5:4>
TMR2 = PR2