PIC18FXX20 Datasheet, PDF (225/366 Pages) Microchip Technology – 64/80-Pin High Performance 1 Mbit Enhanced FLASH Microcontrollers with A/D

PIC18FXX20
20.0 COMPARATOR MODULE
The comparator module contains two analog compara-
tors. The inputs to the comparators are multiplexed
with the RF1 through RF6 pins. The on-chip Voltage
Reference (Section 21.0) can also be an input to the
comparators.
REGISTER 20-1:
CMCON REGISTER
R-0
C2OUT
bit 7
R-0
C1OUT
R/W-0
C2INV
The CMCON register, shown as Register 20-1, con-
trols the comparator input and output multiplexers. A
block diagram of the various comparator configurations
is shown in Figure 20-1.
R/W-0
C1INV
R/W-0
CIS
R/W-0
CM2
R/W-0
CM1
R/W-0
CM0
bit 0
bit 7
C2OUT: Comparator 2 Output bit
When C2INV = 0:
1 = C2 VIN+ > C2 VIN-
0 = C2 VIN+ < C2 VIN-
When C2INV = 1:
1 = C2 VIN+ < C2 VIN-
0 = C2 VIN+ > C2 VIN-
bit 6
C1OUT: Comparator 1 Output bit
When C1INV = 0:
1 = C1 VIN+ > C1 VIN-
0 = C1 VIN+ < C1 VIN-
When C1INV = 1:
1 = C1 VIN+ < C1 VIN-
0 = C1 VIN+ > C1 VIN-
bit 5
C2INV: Comparator 2 Output Inversion bit
1 = C2 output inverted
0 = C2 output not inverted
bit 4
C1INV: Comparator 1 Output Inversion bit
1 = C1 Output inverted
0 = C1 Output not inverted
bit 3
CIS: Comparator Input Switch bit
When CM2:CM0 = 110:
1 = C1 VIN- connects to RF5/AN10
C2 VIN- connects to RF3/AN8
0 = C1 VIN- connects to RF6/AN11
C2 VIN- connects to RF4/AN9
bit 2
CM2:CM0: Comparator Mode bits
Figure 20-1 shows the Comparator modes and CM2:CM0 bit settings
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
 2003 Microchip Technology Inc.
Advance Information
DS39609A-page 223