C517A_99 Datasheet, PDF (114/218 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

On-Chip Peripheral Components
C517A
Figure 6-26 gives an example of how to generate eight different rectangular wave forms at port 5
using a pattern table and a time schedule for these patterns. The patterns are moved into port 5
before the corresponding timer count is reached. The (future) timer count at which the pattern shall
appear at the port must be loaded to register CC4. Thus the user can mask each port bit differently
depending on whether he wants the output to be changed or not.
Concurrent compare is enabled by setting bit COCOEN in special function register CC4EN. A ’1’ in
this bit automatically sets compare mode 1 for register CC4, too. A 3-bit field in special function
register CC4EN determines the additional number of output pins at port 5. Port P1.4/INT2/CC4 is
used as a standard output pin in any compare mode for register CC4.
Pattern Table (8 Bit)
00 _H
55 _H
AAH
FFH
Timer Count
1000 _H
Port Pattern
Compare
CC4H
10
Register
CC4L
00
Port 5 Latch
00 _H
2000H
3000H
Schedule Table (16 Bit)
1000 _H
2000H
3000H
4000H
4000H
P5.7
P5.6
P5.5
P5.4
P5.3
P5.2
P5.1
P5.0
MCT01853
Figure 6-26
Example for a "Concurrent Compare" Waveform at Port 5
Semiconductor Group
6-48