PIC18F2480/2580/4480/4580
Enhanced features are discussed in detail in
Section 17.4 “Enhanced PWM Mode”. Capture,
Compare and single-output PWM functions of the
ECCP module are the same as described for the
standard CCP module.
17.0 ENHANCED
CAPTURE/COMPARE/PWM
(ECCP) MODULE
Note:
The ECCP1 module is implemented only
in PIC18F4X80 (40/44-pin) devices.
The control register for the Enhanced CCP module is
shown in Register 17-1. It differs from the CCP1CON
register in PIC18F2480/2580 devices in that the two
Most Significant bits are implemented to control PWM
functionality.
In PIC18F4480/4580 devices, ECCP1 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
REGISTER 17-1: ECCP1CON REGISTER (ECCP1 MODULE, PIC18F4480/4580 DEVICES)
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
EPWM1M1
EPWM1M0
EDC1B1
EDC1B0
ECCP1M3
ECCP1M2
ECCP1M1
ECCP1M0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
-n = Value at POR
bit 7-6
EPWM1M<1:0>: Enhanced PWM Output Configuration bits
If ECCP1M<3:2> = 00, 01, 10:
xx= P1A assigned as Capture/Compare input/output; P1B, P1C, P1D assigned as port pins
If ECCP1M<3:2> = 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
bit 5-4
EDC1B<1:0>: ECCP1 Module 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 ECCPR1L.
bit 3-0
ECCP1M<3:0>: Enhanced CCP1 Mode Select bits
0000= Capture/Compare/PWM off (resets ECCP1 module)
0001= Reserved
0010= Compare mode; toggle output on match
0011= Reserved
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 ECCP1 pin low; set output on compare match (set ECCP1IF)
1001= Compare mode; initialize ECCP1 pin high; clear output on compare match (set ECCP1IF)
1010= Compare mode; generate software interrupt only; ECCP1 pin reverts to I/O state
1011= Compare mode; trigger special event (ECCP1 resets TMR1 or TMR3, sets ECCP1IF bit and
starts the A/D conversion on ECCP1 match)
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
© 2009 Microchip Technology Inc.
DS39637D-page 177
MICROCHIP [ MICROCHIP ]
