PIC16F7X7
13.0
COMPARATOR MODULE
The comparator module contains two analog com-
parators. 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 voltage reference (Section
can also be an input to
the comparators.
The CMCON register (Register 13-1) controls the
comparator input and output multiplexers. A block
diagram of the various comparator configurations is
shown in Figure 13-1.
REGISTER 13-1:
CMCON: COMPARATOR MODULE CONTROL REGISTER (ADDRESS 9Ch)
R-0
C2OUT
bit 7
R-0
C1OUT
R/W-0
C2INV
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 V
IN
+ > C2 V
IN
-
0
= C2 V
IN
+ < C2 V
IN
-
When C2INV =
1:
1
= C2 V
IN
+ < C2 V
IN
-
0
= C2 V
IN
+ > C2 V
IN
-
C1OUT:
Comparator 1 Output bit
When C1INV =
0:
1
= C1 V
IN
+ > C1 V
IN
-
0
= C1 V
IN
+ < C1 V
IN
-
When C1INV =
1:
1
= C1 V
IN
+ < C1 V
IN
-
0
= C1 V
IN
+ > C1 V
IN
-
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 CM2:CM0 =
110:
1
= C1 V
IN
- connects to RA3/AN3
C2 V
IN
- connects to RA2/AN2
0
= C1 V
IN
- connects to RA0/AN0
C2 V
IN
- connects to RA1/AN1
CM2:CM0:
Comparator Mode bits
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
bit 6
bit 5
bit 4
bit 3
bit 2-0
2004 Microchip Technology Inc.
DS30498C-page 161
MICROCHIP [ MICROCHIP TECHNOLOGY ]
