DV164136 Microchip Technology, DV164136 Datasheet - Page 309

• Manufacturer Part Number: DV164136
• Description: DEVELOPMENT KIT FOR PIC18
• Manufacturer: Microchip Technology
• Series: PIC®r
• Type: MCUr

Specifications of DV164136

• Contents: Board, Cables, CDs, PICkit™ 3 Programmer, Power Supply
• Processor To Be Evaluated: PIC18F8722, PIC18F87J11
• Interface Type: RS-232, USB
• Operating Supply Voltage: 3.3 V, 5 V
• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC18
• Silicon Core Number: PIC18F
• Silicon Family Name: PIC18F8xxx
• Kit Contents: PIC18 Exp Brd PICkit 3 Cable CD PSU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: PIC18F8722, PIC18F87J11
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

22.6
The comparator interrupt flag is set whenever any of
the following occurs:
• Low-to-high transition of the comparator output
• High-to-low transition of the comparator output
• Any change in the comparator output
The comparator interrupt selection is done by the
EVPOL1:EVPOL0 bits in the CMxCON register
(CMxCON<4:3>).
In order to provide maximum flexibility, the output of the
comparator may be inverted using the CPOL bit in the
CMxCON register (CMxCON<5>). This is functionally
identical to reversing the inverting and non-inverting
inputs of the comparator for a particular mode.
An interrupt is generated on the low-to-high or high-to-
low transition of the comparator output. This mode of
interrupt generation is dependent on EVPOL<1:0> in
the CMxCON register. If EVPOL<1:0> = 01 or 10, the
interrupt is generated on a low-to-high or high-to-low
TABLE 22-2:
© 2009 Microchip Technology Inc.
CPOL
Comparator Interrupts
0
1
COMPARATOR INTERRUPT GENERATION
EVPOL<1:0>
00
01
10
11
00
01
10
11
Input Change
Comparator
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
+ > 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
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
PIC18F87J11 FAMILY
transition of the comparator output. Once the interrupt
is generated, it is required to clear the interrupt flag by
software.
When EVPOL<1:0> = 11, the comparator interrupt flag
is set whenever there is a change in the output value of
either comparator. Software will need to maintain infor-
mation about the status of the output bits, as read from
CMSTAT<1:0>, to determine the actual change that
occurred. The CMxIF bits (PIR2<6:5>) are the Compar-
ator Interrupt Flags. The CMxIF bits must be reset by
clearing them. Since it is also possible to write a ‘1’ to
this register, a simulated interrupt may be initiated.
Table 22-2 shows the interrupt generation with respect
to comparator input voltages and EVPOL bit settings.
Both the CMxIE bits (PIE2<6:5>) and the PEIE bit (INT-
CON<6>) must be set to enable the interrupt. In addi-
tion, the GIE bit (INTCON<7>) must also be set. If any
of these bits are clear, the interrupt is not enabled,
though the CMxIF bits will still be set if an interrupt
condition occurs.
COUTx Transition
Low-to-High
High-to-Low
Low-to-High
High-to-Low
Low-to-High
High-to-Low
Low-to-High
High-to-Low
High-to-Low
Low-to-High
High-to-Low
Low-to-High
High-to-Low
Low-to-High
High-to-Low
Low-to-High
DS39778D-page 309
Generated
Interrupt
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No