ECOMn CAPPn CAPNn MATn TOGn PWMm ECCFn
Module Function
1
0
0
1
X
0
X Watchdog Timer (module 4 only)
There are two additional registers associated with each of the PCA modules. They are
CCAPnH and CCAPnL and these are the registers that store the 16-bit count when a
capture occurs or a compare should occur. When a module is used in the PWM mode
these registers are used to control the duty cycle of the output (See Table 14 &
Table 15)
Table 14. CCAPnH: PCA Modules Capture/Compare Registers High
CCAPnH
Address
n=0-4
CCAP0H=0FAH
CCAP1H=0FBH
CCAP2H=0FCH
CCAP3H=0FDH
CCAP4H=0FEH
7
6
5
4
3
2
1
0
Reset value
0
0
0
0
0
0
0
0
Table 15. CCAPnL: PCA Modules Capture/Compare Registers Low
CCAPnL
Address
n=0-4
CCAP0L=0EAH
CCAP1L=0EBH
CCAP2L=0ECH
CCAP3L=0EDH
CCAP4L=0EEH
7
6
5
4
3
2
1
0
Reset value
0
0
0
0
0
0
0
0
Table 16. CH: PCA Counter High
CH
Address 0F9H
7
6
5
4
3
2
1
0
Reset value
0
0
0
0
0
0
0
0
Table 17. CL: PCA Counter Low
CL
Address 0E9H
7
6
5
4
3
2
1
0
Reset value
0
0
0
0
0
0
0
0
28 T89C51RD2
4243G–8051–05/03