Microchip Technology GPIODM-KPLCD Data Sheet

Page of 438
PIC18F2455/2550/4455/4550
DS39632E-page 152
 
© 2009 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 (PWM Dead-Band Delay) 
• ECCP1AS (ECCP Auto-Shutdown Control)
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
P1M1:P1M0 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 Modules and Timer
Resources”
.
16.2
Capture and Compare Modes
Except for the operation of the Special Event Trigger
discussed below, the Capture and Compare modes of
the ECCP module are identical in operation to that of
CCP. These are discussed in detail in Section 15.2
“Capture Mode”
 a
nd Section 15.3 “Compare
Mode”
.
16.2.1
SPECIAL EVENT TRIGGER
The Special Event Trigger output of ECCP resets the
TMR1 or TMR3 register pair, depending on which timer
resource is currently selected. This allows the
CCPR1H:CCPR1L registers to effectively be a 16-bit
programmable period register for Timer1 or Timer3.    
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
operations, users are free to use either of
the processes described in Section 15.4.4
“Setup for PWM Operation”
 or
Section 16.4.9 “Setup for PWM Opera-
tion”
. The latter is more generic but will
work for either single or multi-output PWM.
ECCP Mode
CCP1CON
Configuration
RC2
RD5
RD6
RD7
All PIC18F4455/4550 devices:
Compatible CCP
00xx 11xx
CCP1
RD5/SPP5
RD6/SPP6
RD7/SPP7
Dual PWM
10xx 11xx
P1A
P1B
RD6/SPP6
RD7/SPP7
Quad PWM
x1xx 11xx
P1A
P1B
P1C
P1D
Legend: x = Don’t care. Shaded cells indicate pin assignments not used by ECCP in a given mode.