Cex.n
CF CR
T89C51RD2
CCF4 CCF3 CCF2 CCF1 CCF0 CCON
0xD8
PCA IT
Capture
PCA Counter/Timer
CH
CL
CCAPnH
CCAPnL
ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn CCAPMn, n= 0 to 4
0xDA to 0xDE
Figure 9. PCA Capture Mode
6.5.2. 16-bit Software Timer / Compare Mode
The PCA modules can be used as software timers by setting both the ECOM and MAT bits in the modules
CCAPMn register. The PCA timer will be compared to the module's capture registers and when a match occurs
an interrupt will occur if the CCFn (CCON SFR) and the ECCFn (CCAPMn SFR) bits for the module are both
set (See Figure 10).
Rev. F - 15 February, 2001
28