PIC18FXX20
TABLE 16-1: CCP MODE - TIMER
RESOURCE
16.1 CCP Module Configuration
Each Capture/Compare/PWM module is associated
with a control register (generically, CCPxCON) and a
data register (CCPRx). The data register, in turn, is
comprised of two 8-bit registers: CCPRxL (low byte)
and CCPRxH (high byte). All registers are both
readable and writable.
CCP Mode
Timer Resource
Capture
Compare
PWM
Timer1 or Timer3
Timer1 or Timer3
Timer2 or Timer4
The assignment of a particular timer to a module is
determined by the Timer-to-CCP Enable bits in the
T3CON register (Register 14-1, page 143). Depending
on the configuration selected, up to four timers may be
active at once, with modules in the same configuration
(Capture/Compare or PWM) sharing timer resources.
The possible configurations are shown in Figure 16-1.
16.1.1
CCP MODULES AND TIMER
RESOURCES
The CCP modules utilize Timers 1, 2, 3 or 4, depending
on the mode selected. Timer1 and Timer3 are available
to modules in Capture or Compare modes, while
Timer2 and Timer4 are available for modules in PWM
mode.
FIGURE 16-1:
CCP AND TIMER INTERCONNECT CONFIGURATIONS
T3CCP<2:1> = 00
T3CCP<2:1> = 01
T3CCP<2:1> = 10
T3CCP<2:1> = 11
TMR1
TMR3
TMR1
TMR3
TMR1
TMR3
TMR1
TMR3
CCP1
CCP2
CCP3
CCP4
CCP5
CCP1
CCP1
CCP2
CCP1
CCP2
CCP3
CCP4
CCP5
CCP2
CCP3
CCP4
CCP5
CCP3
CCP4
CCP5
TMR2
TMR4
TMR2
TMR4
TMR2
TMR4
TMR2
TMR4
Timer1 is used for all Capture Timer1 and Timer2 are used Timer1 and Timer2 are used
and Compare operations for for Capture and Compare or for Capture and Compare or
Timer3 is used for all Capture
and Compare operations for
all CCP modules. Timer4 is
used for PWM operations for
all CCP modules. Modules
may share either timer
PWM operations for CCP1
all CCP modules. Timer2 is PWM operations for CCP1
used for PWM operations for only (depending on selected and CCP2 only (depending on
all CCP modules. Modules mode).
the mode selected for each
module). Both modules may
use a timer as a common
time-base if they are both in
Capture/Compare or PWM
modes.
may share either timer
All other modules use either
Timer3 or Timer4. Modules
may share either timer
resource as
time-base.
a
common
resource as
time-base.
a
common
Timer3 and Timer4 are not resource as a common time-
available.
Timer1 and Timer2 are not
available.
base,
if
they
are
in
Capture/Compare or PWM The other modules use either
modes.
Timer3 or Timer4. Modules
may share either timer
resource as a common time-
base
if
they
are
in
Capture/Compare or PWM
modes.
DS39609A-page 150
Advance Information
2003 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
