PIC18F2220 Datasheet, PDF (224/388 Pages) Microchip Technology – 28/40/44-Pin High-Performance, Enhanced Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology

PIC18F2220/2320/4220/4320
FIGURE 20-1:
COMPARATOR I/O OPERATING MODES
Comparators RESET
CM<2:0> = 000
RA0/AN0 ^D
RA3/AN3/ ^D
VREF+
VIN-
VIN+ ^C1
Off (Read as ‘0’)
Comparators Off (POR Default Value)
CM<2:0> = 111
RA0/AN0 ^D
RA3/AN3/ ^D
VREF+
VIN-
VIN+ ^C1
Off (Read as ‘0’)
RA1/AN1 ^D
RA2/AN2/ ^D
VREF-/CVREF
VIN-
VIN+ ^C2
Two Independent Comparators
CM<2:0> = 010
RA0/AN0 ^A
RA3/AN3/ ^A
VREF+
VIN-
VIN+ ^C1
RA1/AN1 ^A
RA2/AN2/ ^A
VREF-/CVREF
VIN-
VIN+ ^C2
Off (Read as ‘0’)
C1OUT
C2OUT
RA1/AN1 ^D
RA2/AN2/ ^D
VREF-/CVREF
VIN-
VIN+ ^C2
Off (Read as ‘0’)
Two Independent Comparators with Outputs
CM<2:0> = 011
A
RA0/AN0
RA3/AN3/ ^A
VIN-
VIN+ ^C1
VREF+
RA4/T0CKI/C1OUT⁽¹⁾
C1OUT
RA1/AN1 ^A
RA2/AN2/ ^A
VREF-/CVREF
VIN-
VIN+ ^C2
C2OUT
RA5/AN4/SS/LVDIN/C2OUT⁽¹⁾
Two Common Reference Comparators
CM<2:0> = 100
RA0/AN0 ^A
RA3/AN3/ ^A
VREF+
VIN-
VIN+ ^C1
C1OUT
RA1/AN1 ^A
RA2/AN2/ ^D
VREF-/CVREF
VIN-
VIN+ ^C2
C2OUT
Two Common Reference Comparators with Outputs
CM<2:0> = 101
A
RA0/AN0
RA3/AN3/
A
VREF+
RA4/T0CKI/C1OUT⁽¹⁾
VIN-
VIN+ ^C1
C1OUT
RA1/AN1
RA2/AN2/
VREF-/CVREF
A
VIN-
D
VIN+ ^C2
RA5/AN4/SS/LVDIN/C2OUT⁽¹⁾
C2OUT
One Independent Comparator with Output
CM<2:0> = 001
RA0/AN0 ^A
RA3/AN3/ ^A
VREF+
VIN-
VIN+ ^C1
RA4/T0CKI/C1OUT⁽¹⁾
C1OUT
RA1/AN1 ^D
RA2/AN2/ ^D
VREF-/CVREF
VIN-
VIN+ ^C2
Off (Read as ‘0’)
Four Inputs Multiplexed to Two Comparators
CM<2:0> = 110
A
RA0/AN0
RA3/AN3/ ^A
VREF+
CIS = 0
CIS = 1
VIN-
VIN+ ^C1
C1OUT
A
RA1/AN1
RA2/AN2/ ^A
VREF-/CVREF
CIS = 0
CIS = 1
CVROE = 0
CVROE = 1
VIN-
VIN+ ^C2
C2OUT
CVREF _{From VREF Module}
A = Analog Input, port reads zeros always, overrides TRISA bit⁽²⁾.
D = Digital Input.
CIS (CMCON<3>) is the Comparator Input Switch; CVROE (CVRCON<6>) is the Voltage Reference Output Switch.
Note 1: RA4 must be configured as an output pin in TRISA<4> when used to output C1OUT. RA5 ignores TRISA<5> when
used as an output for C2OUT.
2: Mode 110 is exception. Comparator input pins obey TRISA bits.
DS39599C-page 222
 2003 Microchip Technology Inc.