PIC16F688
7.3
Comparator Control
The CMCON0 register (Register 7-1) provides access
to the following comparator features:
• Mode selection
• Output state
• Output polarity
• Input switch
7.3.1
COMPARATOR OUTPUT STATE
Each comparator state can always be read internally
via the associated CxOUT bit of the CMCON0 register.
The comparator outputs are directed to the CxOUT
pins when CM<2:0> = 110. When this mode is
selected, the TRIS bits for the associated CxOUT pins
must be cleared to enable the output drivers.
7.3.2
COMPARATOR OUTPUT POLARITY
Inverting the output of a comparator is functionally
equivalent to swapping the comparator inputs. The
polarity of a comparator output can be inverted by set-
ting the CxINV bits of the CMCON0 register. Clearing
CxINV results in a non-inverted output. A complete
table showing the output state versus input conditions
and the polarity bit is shown in Table 7-1.
TABLE 7-1:
OUTPUT STATE VS. INPUT
CONDITIONS
Input Conditions
CxINV
CxOUT
VIN- > VIN+
VIN- < VIN+
VIN- > VIN+
VIN- < VIN+
0
0
1
1
0
1
1
0
Note:
CxOUT refers to both the register bit and
output pin.
DS41203D-page 58
© 2007 Microchip Technology Inc.
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