TS80C51RA2 Atmel Corporation, TS80C51RA2 Datasheet - Page 30

• Manufacturer Part Number: TS80C51RA2
• Description: High Performance 8-bit Microcontroller
• Manufacturer: Atmel Corporation

High Speed Output Mode
Figure 11. PCA High Speed Output Mode
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CCAPnH
Write to
TS8xC51Rx2
1
CCAPnL
Write to
0
Reset
Enable
In this mode the CEX output (on port 1) associated with the PCA module will toggle
each time a match occurs between the PCA counter and the module's capture registers.
To activate this mode the TOG, MAT, and ECOM bits in the module's CCAPMn SFR
must be set (See Figure 11).
A prior write must be done to CCAPnL and CCAPnH before writing the ECOMn bit.
Before enabling ECOM bit, CCAPnL and CCAPnH should be set with a non zero value,
otherwise an unwanted match could happen.
Once ECOM set, writing CCAPnL will clear ECOM so that an unwanted match doesn’t
occur while modifying the compare value. Writing to CCAPnH will set ECOM. For this
reason, user software should write CCAPnL first, and then CCAPnH. Of course, the
ECOM bit can still be controlled by accessing to CCAPMn register.
PCA counter/timer
CCAPnH
CH
16 bit comparator
CF
ECOMn
CCAPnL
CR
CL
CAPPn
Match
CAPNn MATn TOGn PWMn ECCFn
CCF4 CCF3 CCF2 CCF1 CCF0
CCON
0xD8
CCAPMn, n = 0 to 4
0xDA to 0xDE
PCA IT
CEXn
4188A–8051–10/02