PIC16F627A_05 Datasheet, PDF (63/180 Pages) Microchip Technology – Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology

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 “Voltage Reference
Module”) 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 – COMPARATOR CONFIGURATION REGISTER (ADDRESS: 01Fh)
R-0
R-0
R/W-0 R/W-0
R/W-0
R/W-0 R/W-0 R/W-0
C2OUT C1OUT C2INV C1INV
CIS
CM2
CM1
CM0
bit 7
bit 0
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2-0
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-
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-
C2INV: Comparator 2 Output Inversion bit
1 = C2 Output inverted
0 = C2 Output not inverted
C1INV: Comparator 1 Output Inversion bit
1 = C1 Output inverted
0 = C1 Output not inverted
CIS: Comparator Input Switch bit
When CM<2:0>: = 001
Then:
1 = C1 VIN- connects to RA3
0 = C1 VIN- connects to RA0
When CM<2:0> = 010
Then:
1 = C1 VIN- connects to RA3
C2 VIN- connects to RA2
0 = C1 VIN- connects to RA0
C2 VIN- connects to RA1
CM<2:0>: Comparator Mode bits
Figure 10-1 shows the comparator modes and CM<2:0> 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
© 2005 Microchip Technology Inc.
DS40044D-page 61