Counter Clear Upon Compare Match; Figure 15-6. Compare Match And Counter Clear - Sharp Blue Treak LH75400 User Manual

Timers

15.1.2 Counter Clear Upon Compare Match

A compare match occurs when the contents of the Timer Counter Register matches the
value of the corresponding Timer Compare Register. When there is a compare match, one
of two actions occurs, based on the setting of the TC bit in the corresponding Timer
Control Register:
• If TC is set to 0, the counter is not cleared and continues counting.
• If TC is set to 1, the counter is cleared on the rising edge of the internal count clock.
Figure 15-6 shows an example of a timer's count being cleared when the count reaches
the compare match value. This function is available with the compare value stored by the
CMP1 Register. The Compare Match Detect signal shown in Figure 15-6 can be output
through either:
• CTCCMP(n)A if the Timer Compare Register CMP0 is used.
• CTCCMP(n)B if the Timer Compare Register CMP1 is used.
The compare function is clocked by the internal count clock, which is the prescaled
system clock.
COUNT CLOCK
CONTENT OF
COMPARE REGISTER
COMPARE MATCH
DETECT SIGNAL
15-6
SYSTEM
CLOCK
INTERNAL
COUNTER
N-1
VALUE

Figure 15-6. Compare Match and Counter Clear

LH75400/01/10/11 (Preliminary) User's Guide
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6/17/03
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