Datasheet

© 2007 Microchip Technology Inc. DS41232D-page 75
PIC12F635/PIC16F636/639
FIGURE 7-7: COMPARATOR I/O OPERATING MODES (PIC16F636/639)
C1
C1IN-
VIN-
V
IN+
C1IN+
Off
(1)
Comparators Reset (POR Default Value)
A
A
CM<2:0> = 000
C2
C2IN-
VIN-
V
IN+
C2IN+
Off
(1)
A
A
C1
C1IN-
VIN-
V
IN+
C1IN+
C1OUT
Two Independent Comparators
A
A
CM<2:0> = 100
C2
C2IN-
VIN-
V
IN+
C2IN+
C2OUT
A
A
C1
C1IN-
VIN-
V
IN+
C1IN+
C1OUT
Two Common Reference Comparators
A
I/O
CM<2:0> = 011
C2
C2IN-
VIN-
VIN+
C2IN+
C2OUT
A
A
C1
C1IN-
VIN-
V
IN+
C1IN+
Off
(1)
One Independent Comparator
I/O
I/O
CM<2:0> = 101
C2
C2IN-
VIN-
V
IN+
C2IN+
C2OUT
A
A
C1
C1IN-
VIN-
V
IN+
C1IN+
Off
(1)
Comparators Off (Lowest Power)
I/O
I/O
CM<2:0> = 111
C2
C2IN-
VIN-
V
IN+
C2IN+
Off
(1)
I/O
I/O
C1
C1IN-
VIN-
VIN+
C1IN+
C1OUT
Four Inputs Multiplexed to Two Comparators
A
A
CM<2:0> = 010
C2
C2IN-
VIN-
VIN+
C2IN+
C2OUT
A
A
From CVREF Module
CIS = 0
CIS = 1
CIS = 0
CIS = 1
C1
C1IN-
VIN-
V
IN+
C1OUT(pin)
C1OUT
Two Common Reference Comparators with Outputs
A
D
CM<2:0> = 110
C2
C2IN-
VIN-
V
IN+
C2IN+
C2OUT
A
A
C2OUT(pin)
C1
C1IN-
VIN-
VIN+
C1IN+
C1OUT
Three Inputs Multiplexed to Two Comparators
A
A
CM<2:0> = 001
C2
C2IN-
VIN-
VIN+
C2IN+
C2OUT
A
A
CIS = 0
CIS = 1
D
Legend: A = Analog Input, ports always reads ‘0’ CIS = Comparator Input Switch (CMCON0<3>)
I/O = Normal port I/O D = Comparator Digital Output
Note 1: Reads as ‘0’, unless CxINV = 1.