Fujitsu MB90460 Series, Hardware Manual, Page: 471 / 739

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CHAPTER 16 PWC Timer
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Stopping the timer
In one-shot timer mode or single measurement mode, measurement is automatically discontinued when the
timer overflows or at the end of a count. The user need not know if the timer has stopped. However, in
other modes, the timer must be stopped. This is also true when the timer is to be stopped before the timer
automatically stops.
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Checking operation state
The previously described STRT and STOP bits function as bits that indicate the operation state of the timer
during a read operation. Table 16.6-3 lists the contents of the indicated values
During a read operation, both the STRT bit and the STOP bit have the same value. However, during a read
operation using the read modify write instruction (such as bit manipulation instruction), the values of the
bits are always 11
B
. Do not use this instruction to read the values of the bits.
■
Clearing theTimer
In the following cases, the 16-bit up-count timer is cleared to "0000
H
":
• During reset
• When a count has started after the count start edge is detected in the pulse-width measurement mode
Table 16.6-3 Functions of Operation State Indication Bits
STRT STOP Operation state
0 0
Timer is stopping (except measurement start edge wait state).
The bits indicate that the timer has not started or a measurement has terminated.
1 1 Measurement start edge wait state or timer count operation