PIC18LF8720 Microchip Technology, PIC18LF8720 Datasheet - Page 226

• Manufacturer Part Number: PIC18LF8720
• Description: (PIC18LF6620/6520/8520/6620/8620/6720/8720) 64/80-Pin High-Performance / 64-Kbyte Enhanced Flash Microcontrollers
• Manufacturer: Microchip Technology

PIC18F6520/8520/6620/8620/6720/8720
20.1
There are eight modes of operation for the compara-
tors. The CMCON register is used to select these
modes. Figure 20-1 shows the eight possible modes.
The TRISF register controls the data direction of the
comparator pins for each mode. If the Comparator
mode is changed, the comparator output level may not
FIGURE 20-1:
DS39609B-page 224
Comparators Reset (POR Default Value)
CM2:CM0 = 000
Two Independent Comparators
CM2:CM0 = 010
Two Common Reference Comparators
CM2:CM0 = 100
One Independent Comparator with Output
CM2:CM0 = 001
A = Analog Input, port reads zeros always
RF6/AN11
RF5/AN10
RF4/AN9
RF3/AN8
RF6/AN11
RF5/AN10
RF4/AN9
RF3/AN8
RF6/AN11
RF5/AN10
RF4/AN9
RF3/AN8
RF6/AN11
RF5/AN10
RF2/AN7/C1OUT
RF4/AN9
RF3/AN8
Comparator Configuration
A
A
A
A
A
A
A
A
A
A
A
D
A
A
D
D
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
COMPARATOR I/O OPERATING MODES
-
+
-
+
-
+
-
+
-
+
-
+
-
+
-
+
C1
C2
C1
C2
C1
C2
C1
C2
Off
Off
C1OUT
C2OUT
C1OUT
C2OUT
C1OUT
Off
(Read as
(Read as
(Read as
D = Digital Input
‘0’
‘0’
‘0’
)
)
)
Two Common Reference Comparators with Outputs
CM2:CM0 = 101
Two Independent Comparators with Outputs
CM2:CM0 = 011
Comparators Off
CM2:CM0 = 111
Four Inputs Multiplexed to Two Comparators
CM2:CM0 = 110
RF2/AN7/C1OUT
RF6/AN11
RF5/AN10
RF2/AN7/C1OUT
RF4/AN9
RF3/AN8
RF1/AN6/C2OUT
RF6/AN11
RF5/AN10
RF4/AN9
RF3/AN8
RF1/AN6/C2OUT
RF6/AN11
RF5/AN10
RF4/AN9
RF3/AN8
RF6/AN11
RF5/AN10
RF4/AN9
RF3/AN8
be valid for the specified mode change delay shown in
the Electrical Specifications (Section 26.0 “Electrical
Characteristics”).
CIS (CMCON<3>) is the Comparator Input Switch
Note:
A
A
A
D
A
A
A
A
D
D
D
D
A
A
A
A
Comparator interrupts should be disabled
during a Comparator mode change.
Otherwise, a false interrupt may occur.
V
V
V
V
V
V
V
V
V
V
V
V
CIS = 0
CIS = 1
CIS = 0
CIS = 1
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
-
+
-
+
-
+
-
+
-
+
-
+
C1
C2
 2004 Microchip Technology Inc.
C1
C2
C1
C2
V
V
V
V
IN
IN
IN
IN
CV
-
+
-
+
REF
C1OUT
C2OUT
C1OUT
C2OUT
Off
Off
C1
C2
From V
(Read as
(Read as
REF
C1OUT
C2OUT
‘0’
‘0’
Module
)
)