PIC18F25K20T-ISO Datasheet, PDF (174/456 Pages) Microchip Technology – 28/40/44-Pin Flash Microcontrollers with nanoWatt XLP Technology

PIC18F2XK20/4XK20
In addition to the expanded range of modes available
through the CCP1CON register and ECCP1AS
register, the ECCP module has two additional registers
associated with Enhanced PWM operation and
auto-shutdown features. They are:
• PWM1CON (Dead-band delay)
• PSTRCON (output steering)
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 (for
PIC18F4XK20 devices) or PORTB (for PIC18F2XK20
devices). 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 P1M<1:0>
and CCP1M<3:0> 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 11.1.1 “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
CCP2. These are discussed in detail in Section 11.2
“Capture Mode” and Section 11.3 “Compare
Mode”. No changes are required when moving
between 28-pin and 40/44-pin devices.
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 CCPR1
register 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 11.4
“PWM Mode”. This is also sometimes referred to as
“Single CCP” mode, as in Table 16-1.
DS41303G-page 174
 2010 Microchip Technology Inc.