PIC18F45J10 FAMILY
The CMCON register (Register 19.1) selects the
comparator input and output configuration. Block
diagrams of the various comparator configurations are
shown in Figure 19-1.
19.0 COMPARATOR MODULE
The analog comparator module contains two
comparators that can be configured in a variety of
ways. The inputs can be selected from the analog
inputs multiplexed with pins RA0 through RA5, as well
as the on-chip voltage reference (see Section 20.0
“Comparator Voltage Reference Module”). The digi-
tal outputs (normal or inverted) are available at the pin
level and can also be read through the control register.
REGISTER 19-1: CMCON: COMPARATOR CONTROL REGISTER
R-0
R-0
R/W-0
C2INV
R/W-0
C1INV
R/W-0
CIS
R/W-1
CM2
R/W-1
CM1
R/W-1
CM0
C2OUT
C1OUT
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
-n = Value at POR
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
bit 4
bit 3
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> = 110:
1= C1 VIN- connects to RA3/AN3/VREF+
C2 VIN- connects to RA2/AN2/VREF-/CVREF
0= C1 VIN- connects to RA0/AN0
C2 VIN- connects to RA1/AN1
bit 2-0
CM<2:0>: Comparator Mode bits
Figure 19-1 shows the Comparator modes and the CM<2:0> bit settings.
© 2009 Microchip Technology Inc.
DS39682E-page 225
MICROCHIP [ MICROCHIP ]
