PIC16F818/819
The CCP module’s input/output pin (CCP1) can be
configured as RB2 or RB3. This selection is set in bit 12
(CCPMX) of the Configuration Word register.
9.0
CAPTURE/COMPARE/PWM
(CCP) MODULE
The Capture/Compare/PWM (CCP) module contains a
16-bit register that can operate as a:
Additional information on the CCP module is available
in the “PICmicro® Mid-Range MCU Family Reference
Manual” (DS33023) and in Application Note AN594,
“Using the CCP Module(s)” (DS00594).
•
•
•
16-bit Capture register
16-bit Compare register
PWM Master/Slave Duty Cycle register
TABLE 9-1:
CCP MODE – TIMER
RESOURCE
Table 9-1 shows the timer resources of the CCP
module modes.
CCP Mode
Timer Resource
Capture/Compare/PWM Register 1 (CCPR1) is com-
prised of two 8-bit registers: CCPR1L (low byte) and
CCPR1H (high byte). The CCP1CON register controls
the operation of CCP1. The special event trigger is
generated by a compare match which will reset Timer1
and start an A/D conversion (if the A/D module is
enabled).
Capture
Compare
PWM
Timer1
Timer1
Timer2
REGISTER 9-1:
CCP1CON: CAPTURE/COMPARE/PWM CONTROL REGISTER 1 (ADDRESS 17h)
U-0
—
U-0
—
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
CCP1X
CCP1Y CCP1M3 CCP1M2 CCP1M1 CCP1M0
bit 0
bit 7
bit 7-6
bit 5-4
Unimplemented: Read as ‘0’
CCP1X:CCP1Y: PWM Least Significant bits
Capture mode:
Unused.
Compare mode:
Unused.
PWM mode:
These bits are the two LSbs of the PWM duty cycle. The eight MSbs are found in CCPRxL.
bit 3-0
CCP1M3:CCP1M0: CCP1 Mode Select bits
0000= Capture/Compare/PWM disabled (resets CCP1 module)
0100= Capture mode, every falling edge
0101= Capture mode, every rising edge
0110= Capture mode, every 4th rising edge
0111= Capture mode, every 16th rising edge
1000= Compare mode, set output on match (CCP1IF bit is set)
1001= Compare mode, clear output on match (CCP1IF bit is set)
1010= Compare mode, generate software interrupt on match (CCP1IF bit is set, CCP1 pin is
unaffected)
1011= Compare mode, trigger special event (CCP1IF bit is set, CCP1 pin is unaffected);
CCP1 resets TMR1 and starts an A/D conversion (if A/D module is enabled)
11xx= PWM mode
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
2004 Microchip Technology Inc.
DS39598E-page 65
MICROCHIP [ MICROCHIP ]
