PIC16F627A Datasheet, PDF (63/168 Pages) Microchip Technology – FLASH-Based 8-Bit CMOS Microcontrollers

PIC16F627A/628A/648A
10.0 COMPARATOR MODULE
The Comparator module contains two analog
comparators. The inputs to the comparators are
multiplexed with the RA0 through RA3 pins. The on-
chip Voltage Reference (Section 11.0) can also be an
input to the comparators.
The CMCON register, shown in Register 10-1, controls
the comparator input and output multiplexers. A block
diagram of the comparator is shown in Figure 10-1.
REGISTER 10-1:
CMCON REGISTER (ADDRESS: 01Fh)
R-0
R-0
R/W-0 R/W-0
C2OUT C1OUT C2INV C1INV
bit 7
R/W-0
CIS
R/W-0
CM2
R/W-0
CM1
R/W-0
CM0
bit 0
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2-0
C2OUT: Comparator 2 Output
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-
C1OUT: Comparator 1 Output
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-
C2INV: Comparator 2 Output Inversion
1 = C2 Output inverted
0 = C2 Output not inverted
C1INV: Comparator 1 Output Inversion
1 = C1 Output inverted
0 = C1 Output not inverted
CIS: Comparator Input Switch
When CM2:CM0: = 001
Then:
1 = C1 VIN- connects to RA3
0 = C1 VIN- connects to RA0
When CM2:CM0 = 010
Then:
1 = C1 VIN- connects to RA3
C2 VIN- connects to RA2
0 = C1 VIN- connects to RA0
C2 VIN- connects to RA1
CM2:CM0: Comparator Mode
Figure 10-1 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
 2002 Microchip Technology Inc.
Preliminary
DS40044A-page 61