PIC16F193X Datasheet, PDF (193/418 Pages) Microchip Technology – 28/40/44-Pin Flash-Based, 8-Bit CMOS Microcontrollers with LCD Driver and nanoWatt Technology

19.5 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:
• PRx
• TxCON
• CCPRxL
• CCPxCON
The ECCP modules have the following additional
registers:
• ECCPxAS
• PSTRxCON
• PWMxCON
In Pulse-Width Modulation (PWM) mode, the CCPx
module produces up to a 10-bit resolution PWM output
on the CCPx pin. Since the CCPx pin is multiplexed
with the PORT data latch, the TRIS for that pin must be
cleared to enable the CCPx pin output driver.
Note: Clearing the CCPxCON register will
relinquish CCPx control of the CCPx pin.
The CCPx module in PWM mode can have the PWM
based off of either Timer2, Timer4 or TImer6. This is
controlled by the CCPTMRS0 and CCPTMRS1
registers. Reference Section 19.2 “CCP Clock
Selection” for more information.
Figure 19-3 shows a simplified block diagram of PWM
operation.
Figure 19-4 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 19.5.7
“Setup for PWM Operation”.
PIC16F193X/LF193X
FIGURE 19-3:
SIMPLIFIED PWM BLOCK
DIAGRAM
CCPxCON<5:4>
Duty Cycle Registers
CCPRxL
CCPRxH⁽²⁾ (Slave)
Comparator
RQ
CCPx
TMRx
(1)
S
TRIS
Comparator
PRx
Clear Timerx,
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.
The PWM output (Figure 19-4) has a time base
(period) and a time that the output stays high (duty
cycle).
FIGURE 19-4:
Period
CCP PWM OUTPUT
Pulse Width
TMRX = 0
TMRx = PRx
TMRx\2 = CCPRxH:CCPxCON<5:4>
© 2008 Microchip Technology Inc.
Preliminary
DS41364A-page 191