Owner manual

Rev. F - 15 February, 2001 28
T89C51RD2
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).
CF CR
CCON
0xD8
CH CL
CCAPnH CCAPnL
CCF4
CCF3
CCF2 CCF1 CCF0
PCA IT
PCA Counter/Timer
ECOMn
CCAPMn, n= 0 to 4
0xDA to 0xDE
CAPNn MATn TOGn PWMn ECCFnCAPPn
Cex.n
Capture