
PIC18F2480/2580/4480/4580
DS39637A-page 174
Preliminary
2004 Microchip Technology Inc.
In addition to the expanded range of modes available
through the CCP1CON register, the ECCP module has
two additional registers associated with Enhanced
PWM operation and auto-shutdown features. They are:
ECCP1DEL (Dead-band delay)
ECCP1AS (Auto-shutdown configuration)
16.1
ECCP Outputs and Configuration
The Enhanced CCP module may have up to four PWM
outputs, depending on the selected operating mode.
These outputs, designated P1A through P1D, are
multiplexed with I/O pins on PORTC and PORTD. The
outputs that are active depend on the CCP operating
mode selected. The pin assignments are summarized
in Table 16-1.
To configure the I/O pins as PWM outputs, the proper
PWM mode must be selected by setting the
EPWM1M1:EPWM1M0 and CCP1M3:CCP1M0 bits.
The appropriate TRISC and TRISD direction bits for the
port pins must also be set as outputs.
16.1.1
ECCP MODULES AND TIMER
RESOURCES
Like the standard CCP modules, the ECCP module can
utilize Timers 1, 2 or 3, depending on the mode
selected. Timer1 and Timer3 are available for modules
in Capture or Compare modes, while Timer2 is
available for modules in PWM mode. Interactions
between the standard and Enhanced CCP modules are
identical to those described for standard CCP modules.
Additional details on timer resources are provided in
Section 15.1.1
“CCP
Resources”
.
Modules
and
Timer
16.2
Capture and Compare Modes
Except for the operation of the special event trigger dis-
cussed below, the Capture and Compare modes of the
ECCP1 module are identical in operation to that of
CCP1. These are discussed in detail in
Section 15.2
“Capture Mode”
and
Section 15.3 “Compare
Mode”
.
16.2.1
SPECIAL EVENT TRIGGER
The special event trigger output of ECCP1 resets the
TMR1 or TMR3 register pair, depending on which timer
resource is currently selected. This allows the ECCP1
register to effectively be a 16-bit programmable period
register for Timer1 or Timer3. The special event trigger
for ECCP1 can also start an A/D conversion. In order to
start the conversion, the A/D converter must be
previously enabled.
16.3
Standard PWM Mode
When configured in Single Output mode, the ECCP
module functions identically to the standard CCP
module in PWM mode, as described in
Section 15.4
“PWM Mode”
. This is also sometimes referred to as
“Compatible CCP” mode, as in Table 16-1.
TABLE 16-1:
PIN ASSIGNMENTS FOR VARIOUS ECCP1 MODES
Note:
When setting up single output PWM opera-
tions, users are free to use either of the
processes described in
Section 15.4.4
“Setup
for
PWM
Section 16.4.9 “Setup for PWM Opera-
tion”
. The latter is more generic, but will
work for either single or multi-output PWM.
Operation”
or
ECCP Mode
CCP1CON
Configuration
RD4
RD5
RD6
RD7
All PIC18F4480/4580 devices:
CCP1
P1A
P1A
Compatible CCP
Dual PWM
Quad PWM
Legend:
00xx 11xx
RD5/PSP5
P1B
P1B
RD6/PSP6
RD6/PSP6
P1C
RD7/PSP7
RD7/PSP7
P1D
10xx 11xx
x1xx 11xx
x
= Don’t care. Shaded cells indicate pin assignments not used by ECCP1 in a given mode.