PIC18F2585_07 Datasheet, PDF (176/482 Pages) Microchip Technology – Enhanced Flash Microcontrollers with ECAN Technology, 10-Bit A/D and nanoWatt Technology

PIC18F2585/2680/4585/4680
In addition to the expanded range of modes available
through the CCP1CON register, the ECCP1 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 ECCP1 Outputs and Configuration
The Enhanced CCP1 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 CCP1
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 ECCP1 MODULES AND TIMER
RESOURCES
Like the standard CCP1 modules, the ECCP1 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 CCP1 modules
are identical to those described for standard CCP1
modules. Additional details on timer resources are
provided in Section 15.1.1 “CCP1 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 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 ECCP1
module functions identically to the standard CCP1
module in PWM mode, as described in Section 15.4
“PWM Mode”. This is also sometimes referred to as
“Compatible CCP1” mode, as in Table 16-1.
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 Operation”.
The latter is more generic but will work for
either single or multi-output PWM.
TABLE 16-1: PIN ASSIGNMENTS FOR VARIOUS ECCP1 MODES
ECCP1 Mode
CCP1CON
Configuration
RD4
RD5
RD6
RD7
All PIC18F4585/4680 devices:
Compatible CCP1
00xx 11xx
CCP1
RD5/PSP5
RD6/PSP6
RD7/PSP7
Dual PWM
10xx 11xx
P1A
P1B
RD6/PSP6
RD7/PSP7
Quad PWM
x1xx 11xx
P1A
P1B
P1C
P1D
Legend: x = Don’t care. Shaded cells indicate pin assignments not used by ECCP1 in a given mode.
DS39625C-page 174
Preliminary
© 2007 Microchip Technology Inc.