Start And Stop Of Timer/Pulse Width Measurement - Fujitsu MB90480 Series Hardware Manual

25.5.4 Start and Stop of Timer/Pulse Width Measurement

Start/restart/stop/forcible stop of each operation are controlled by setting the PWCSR:
bit15, bit14 (STRT, STOP bits).
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Start and Stop of timer/pulse width measurement
Start/restart of the timer/pulse width measurement is initiated by setting the STRT bit to "0",
while a forcible stop is initiated by setting the STOP bit to "0". However, this is only effective if
the values are complementary to each other. When using instructions other than bit operation
instructions (such as byte instructions), be sure to set only the bit combinations indicated in
Table 25.5-3.
Table 25.5-3 Function of STRT bit and STOP bit
STRT
0
1
When using bit operation instructions (the clear bit-operation instruction), special care is not
required, since the hardware will ensure that only the combinations of values indicated in Table
25.5-3 are written.
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Operation after measurement start
The operation of timer mode and pulse width measurement mode after measurement start are
as follows.
❍ Timer mode
Count operation starts immediately.
❍ Pulse width measurement mode
Counting will not start until the measurement start edge is detected. After the measurement start
edge is detected, the 16-bit up-count timer is cleared to "0000
CHAPTER 25 PWC TIMER (ONLY MB90485 SERIES)
STOP
1 Start/restart of timer/pulse width measurement
0 Forcible stop of timer/pulse width measurement
Function
" to start counting.
B
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