PIC16LF877A-I Datasheet, PDF (137/234 Pages) Microchip Technology – 28/40/44-Pin Enhanced Flash Microcontrollers

PIC16F87XA
12.0 COMPARATOR MODULE
The comparator module contains two analog compara-
tors. The inputs to the comparators are multiplexed
with I/O port pins RA0 through RA3, while the outputs
are multiplexed to pins RA4 and RA5. The on-chip volt-
age reference (Section 13.0 “Comparator Voltage
Reference Module”) can also be an input to the
comparators.
REGISTER 12-1:
CMCON REGISTER
R-0
R-0
C2OUT C1OUT
bit 7
R/W-0
C2INV
The CMCON register (Register 12-1) controls the com-
parator input and output multiplexers. A block diagram
of the various comparator configurations is shown in
Figure 12-1.
R/W-0
C1INV
R/W-0
CIS
R/W-1
CM2
R/W-1
CM1
R/W-1
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 RA3/AN3
C2 VIN- connects to RA2/AN2
0 = C1 VIN- connects to RA0/AN0
C2 VIN- connects to RA1/AN1
bit 2
CM2:CM0: Comparator Mode bits
Figure 12-1 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.
DS39582B-page 135