PIC18F2525_08 Datasheet, PDF (149/412 Pages) Microchip Technology – 28/40/44-Pin Enhanced Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology

PIC18F2525/2620/4525/4620
16.0 ENHANCED CAPTURE/
COMPARE/PWM (ECCP)
MODULE
Note: The ECCP module is implemented only in
40/44-pin devices.
In PIC18F4525/4620 devices, CCP1 is implemented
as a standard CCP module with Enhanced PWM
capabilities. These include the provision for 2 or 4
output channels, user-selectable polarity, dead-band
control and automatic shutdown and restart. The
Enhanced features are discussed in detail in
Section 16.4 “Enhanced PWM Mode”. Capture,
Compare and single-output PWM functions of the
ECCP module are the same as described for the
standard CCP module.
The control register for the Enhanced CCP module is
shown in Register 16-1. It differs from the CCPxCON
registers in PIC18F2525/2620 devices in that the two
Most Significant bits are implemented to control PWM
functionality.
REGISTER 16-1: CCP1CON: ECCP CONTROL REGISTER (40/44-PIN DEVICES)
R/W-0
P1M1
bit 7
R/W-0
P1M0
R/W-0
DC1B1
R/W-0
DC1B0
R/W-0
CCP1M3
R/W-0
CCP1M2
R/W-0
CCP1M1
R/W-0
CCP1M0
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-6
bit 5-4
bit 3-0
P1M1:P1M0: Enhanced PWM Output Configuration bits
If CCP1M3:CCP1M2 = 00, 01, 10:
xx = P1A assigned as capture/compare input/output; P1B, P1C, P1D assigned as port pins
If CCP1M3:CCP1M2 = 11:
00 = Single output, P1A modulated; P1B, P1C, P1D assigned as port pins
01 = Full-bridge output forward, P1D modulated; P1A active; P1B, P1C inactive
10 = Half-bridge output, P1A, P1B modulated with dead-band control; P1C, P1D assigned as port pins
11 = Full-bridge output reverse, P1B modulated; P1C active; P1A, P1D inactive
DC1B1:DC1B0: PWM Duty Cycle bit 1 and bit 0
Capture mode:
Unused.
Compare mode:
Unused.
PWM mode:
These bits are the two LSbs of the 10-bit PWM duty cycle. The eight MSbs of the duty cycle are found in
CCPR1L.
CCP1M3:CCP1M0: Enhanced CCP Mode Select bits
0000 = Capture/Compare/PWM off (resets ECCP module)
0001 = Reserved
0010 = Compare mode, toggle output on match
0011 = Capture mode
0100 = Capture mode, every falling edge
0101 = Capture mode, every rising edge
0110 = Capture mode, every 4th rising edge
0111 = Capture mode, every 16th rising edge
1000 = Compare mode, initialize CCP1 pin low; set output on compare match (set CCP1IF)
1001 = Compare mode, initialize CCP1 pin high; clear output on compare match (set CCP1IF)
1010 = Compare mode, generate software interrupt only; CCP1 pin reverts to I/O state
1011 = Compare mode, trigger special event (ECCP resets TMR1 or TMR3, sets CCP1IF bit)
1100 = PWM mode, P1A, P1C active-high; P1B, P1D active-high
1101 = PWM mode, P1A, P1C active-high; P1B, P1D active-low
1110 = PWM mode, P1A, P1C active-low; P1B, P1D active-high
1111 = PWM mode, P1A, P1C active-low; P1B, P1D active-low
© 2008 Microchip Technology Inc.
DS39626E-page 147