Datasheet

© 2009 Microchip Technology Inc. DS39775C-page 337
PIC18F87J50 FAMILY
23.0 COMPARATOR MODULE
The analog comparator module contains two compara-
tors that can be independently configured in a variety of
ways. The inputs can be selected from the analog
inputs and two internal voltage references. The digital
outputs are available at the pin level and can also be
read through the control register. Multiple output and
interrupt event generation are also available. A generic
single comparator from the module is shown in
Figure 23-1.
Key features of the module includes:
• Independent comparator control
• Programmable input configuration
• Output to both pin and register levels
• Programmable output polarity
• Independent interrupt generation for each
comparator with configurable interrupt-on-change
23.1 Registers
The CMxCON registers (Register 23-1) select the input
and output configuration for each comparator, as well
as the settings for interrupt generation.
The CMSTAT register (Register 23-2) provides the out-
put results of the comparators. The bits in this register
are read-only.
FIGURE 23-1: COMPARATOR SIMPLIFIED BLOCK DIAGRAM
Cx
VIN-
V
IN+
COE
CxOUT
0
1
(1)
2
(1,2)
3
0
1
CCH1:CCH0
CxINB
CxINC
CxIND
V
IRV
CxINA
CV
REF
CON
Interrupt
Logic
EVPOL<4:3>
COUTx
(CMSTAT<1:0>)
CMxIF
CPOL
Polarity
Logic
CREF
Note 1: Available in 80-pin devices only.
2: Implemented in Comparator 2 only.