PIC16F87X
8.0
CAPTURE/COMPARE/PWM
MODULES
CCP2 Module:
Capture/Compare/PWM Register1 (CCPR2) is com-
prised of two 8-bit registers: CCPR2L (low byte) and
CCPR2H (high byte). The CCP2CON register controls
the operation of CCP2. The special event trigger is gen-
erated by a compare match and will reset Timer1 and
start an A/D conversion (if the A/D module is enabled).
Additional information on CCP modules is available in
the PICmicro™ Mid-Range MCU Family Reference
Manual (DS33023) and in Application Note 594, “Using
the CCP Modules” (DS00594).
Each Capture/Compare/PWM (CCP) module contains
a 16-bit register which can operate as a:
• 16-bit Capture register
• 16-bit Compare register
• PWM master/slave Duty Cycle register
Both the CCP1 and CCP2 modules are identical in
operation, with the exception being the operation of the
special event trigger.
and
show the
resources and interactions of the CCP module(s). In
the following sections, the operation of a CCP module
is described with respect to CCP1. CCP2 operates the
same as CCP1, except where noted.
CCP1 Module:
Capture/Compare/PWM Register1 (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 gen-
erated by a compare match and will reset Timer1.
TABLE 8-1:
CCP MODE - TIMER
RESOURCES REQUIRED
Timer Resource
Timer1
Timer1
Timer2
CCP Mode
Capture
Compare
PWM
TABLE 8-2:
INTERACTION OF TWO CCP MODULES
Interaction
Same TMR1 time-base.
The compare should be configured for the special event trigger, which clears TMR1.
The compare(s) should be configured for the special event trigger, which clears TMR1.
The PWMs will have the same frequency and update rate (TMR2 interrupt).
None.
None.
CCPx Mode CCPy Mode
Capture
Capture
Compare
PWM
PWM
PWM
Capture
Compare
Compare
PWM
Capture
Compare
1999 Microchip Technology Inc.
DS30292B-page 57
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