PIC18F24J11 MICROCHIP [Microchip Technology], PIC18F24J11 Datasheet - Page 249

• Manufacturer Part Number: PIC18F24J11
• Description: 28/44-Pin, Low-Power, High-Performance USB Microcontrollers with nanoWatt XLP Technology
• Manufacturer: MICROCHIP [Microchip Technology]

In addition to the expanded range of modes available
through the CCPxCON and ECCPxAS registers, the
ECCP modules have two additional registers associated
with Enhanced PWM operation and auto-shutdown
features. They are:
• ECCPxDEL (Enhanced PWM Control)
• PSTRxCON (Pulse Steering Control)
18.1
The Enhanced CCP module may have up to four PWM
outputs, depending on the selected operating mode.
These outputs, designated PxA through PxD, are
routed through the Peripheral Pin Select (PPS)
module. Therefore, individual functions may be
mapped to any of the remappable I/O pins, RPn. The
outputs that are active depend on the ECCP operating
mode selected. The pin assignments are summarized
in
To configure the I/O pins as PWM outputs, the proper
PWM mode must be selected by setting the PxM<1:0>
and CCPxM<3:0> bits. The appropriate TRIS direction
bits for the port pins must also be set as outputs and the
output functions need to be assigned to I/O pins in the
PPS module. (For details on configuring the module,
see Section 10.7 “Peripheral Pin Select (PPS)”.)
18.1.1
The ECCP 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.
TABLE 18-1:
The assignment of a particular timer to a module is
determined by the Timer-to-ECCP enable bits in the
TCLKCON register
between the two modules are depicted in
Capture operations are designed to be used when the
timer is configured for Synchronous Counter mode.
Capture operations may not work as expected if the
associated timer is configured for Asynchronous Counter
mode.
 2011 Microchip Technology Inc.
Table
ECCP Mode
Compare
18-4.
Capture
ECCP Outputs and Configuration
PWM
ECCP MODULE AND TIMER
RESOURCES
ECCP MODE – TIMER
RESOURCE
(Register
13-3). The interactions
Timer1 or Timer3
Timer1 or Timer3
Timer2 or Timer4
Timer Resource
Figure
18-1.
PIC18F46J11 FAMILY
18.2
In Capture mode, the CCPRxH:CCPRxL register pair
captures the 16-bit value of the TMR1 or TMR3
registers when an event occurs on the corresponding
ECCPx pin. An event is defined as one of the following:
• Every falling edge
• Every rising edge
• Every 4
• Every 16
The event is selected by the mode select bits,
CCPxM<3:0>, of the CCPxCON register. When a
capture is made, the interrupt request flag bit, CCPxIF,
is set; it must be cleared by software. If another capture
occurs before the value in register CCPRx is read, the
old captured value is overwritten by the new captured
value.
18.2.1
In Capture mode, the appropriate ECCPx pin should be
configured as an input by setting the corresponding
TRIS direction bit.
Additionally, the ECCPx input function needs to be
assigned to an I/O pin through the Peripheral Pin
Select module. For details on setting up the
remappable pins, see Section 10.7 “Peripheral Pin
Select (PPS)”.
18.2.2
The timers that are to be used with the capture feature
(Timer1 and/or Timer3) must be running in Timer mode
or Synchronized Counter mode. In Asynchronous
Counter mode, the capture operation may not work.
The timer to be used with each ECCP module is
selected in the TCLKCON register
18.2.3
When the Capture mode is changed, a false capture
interrupt may be generated. The user should keep the
CCPxIE interrupt enable bit clear to avoid false interrupts.
The interrupt flag bit, CCPxIF, should also be cleared
following any such change in operating mode.
Note:
Capture Mode
th
th
ECCP PIN CONFIGURATION
If the ECCPx pin is configured as an out-
put, a write to the port can cause a capture
condition.
TIMER1/TIMER3 MODE SELECTION
SOFTWARE INTERRUPT
rising edge
rising edge
(Register
DS39932D-page 249
13-3).