Fujitsu F2MC-16LX MB90580 Series Hardware Manual page 286

18.5 Precautions
(8) Divided Period Count Mode
Note that the input pulses are divided when divided period count mode is used in pulse width count mode
and therefore the pulse width calculated from the count result is an average value.
(9) Restarting the Timer During Operation
Depending on the timing, the following may occur when the timer is restarted after starting the count
operation.
(a) If the restart occurs at the same time as an overflow in reload timer mode:
The timer restarts but the overflow flag (OVIR) is set and the POUT bit inverted. (That is, the same
operations are performed as for a normal overflow.)
(b) If the restart occurs at the same time as the count end edge in single-shot pulse width count mode:
The timer restarts and waits for a count start edge but the count end flag (EDIR) is also set.
(c) If the restart occurs at the same time as the count end edge in continuous pulse width count mode:
The timer restarts and waits for a count start edge but the count end flag (EDIR) is also set and the
count result at that time is transferred to PWCR.
When restarting the timer while it is still operating, take note of the operation of the flags as described
above and perform interrupt and other control accordingly.
(10) Pulse Width Count Mode Using Continuous Count Mode
Note that, when performing continuous counting in this mode, the divider circuit for the internal count clock
is not cleared and therefore the number of edges below the count clock is added to the result.
266 Chapter 18: Pulse Width Counter (PWC) Timer MB90580 Series