
40
4235K–8051–05/08
AT89C51RD2/ED2
Table 13-3 shows the CCAPMn settings for the various PCA functions.
Table 13-3.
CCAPMn Registers (n = 0-4)
CCAPM0 - PCA Module 0 Compare/Capture Control Register (0DAh)
CCAPM1 - PCA Module 1 Compare/Capture Control Register (0DBh)
CCAPM2 - PCA Module 2 Compare/Capture Control Register (0DCh)
CCAPM3 - PCA Module 3 Compare/Capture Control Register (0DDh)
CCAPM4 - PCA Module 4 Compare/Capture Control Register (0DEh)
Reset Value = X000 0000b
Not bit addressable
7
6
5
4
3
2
1
0
-
ECOMn
CAPPn
CAPNn
MATn
TOGn
PWMn
ECCFn
Bit
Number
Bit
Mnemonic
Description
7
-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
6
ECOMn
Enable Comparator
Cleared to disable the comparator function.
Set to enable the comparator function.
5
CAPPn
Capture Positive
Cleared to disable positive edge capture.
Set to enable positive edge capture.
4
CAPNn
Capture Negative
Cleared to disable negative edge capture.
Set to enable negative edge capture.
3
MATn
Match
When MATn = 1, a match of the PCA counter with this module's compare/capture
register causes the CCFn bit in CCON to be set, flagging an interrupt.
2
TOGn
Toggle
When TOGn = 1, a match of the PCA counter with this module's compare/capture
register causes the CEXn pin to toggle.
1
PWMn
Pulse Width Modulation Mode
Cleared to disable the CEXn pin to be used as a pulse width modulated output.
Set to enable the CEXn pin to be used as a pulse width modulated output.
0
CCF0
Enable CCF interrupt
Cleared to disable compare/capture flag CCFn in the CCON register to generate an
interrupt.
Set to enable compare/capture flag CCFn in the CCON register to generate an interrupt.