M38203M4 Datasheet, PDF (188/344 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.4 Timer 1, timer 2, and timer 3
2.4.5 Notes on use
(1) Notes on using timer 1 to timer 3
sWhen the count sources of timers 1 to 3 are switched, a short pulse occurs in counted input signals,
so the timer count value may change greatly.
sWhen the timer 1 output is selected as a count source of timer 2 or timer 3, a short pulse occurs in
the output signal at writing value into the timer 1, so the count value of the timer 2 or timer 3 may
change greatly.
sFor the above reasons, set values in the order of timer 1, timer 2, and timer 3 after setting their count
sources.
(2) Timer 2 write control
When writing to the latch only is selected, the value written into the timer 2 (address 002516) is written
only in the latch for reloading. This rewritten value is transferred to the timer 2 counter at the first
underflow after rewriting.
Usually, a value is written in both the latch and the counter at the same time. That is, when a value
is written to timer, it is set in both the latch and the counter.
(3) Timer 2 output control
In the timer 2 (TOUT) output enable state, a signal whose polarity is reversed each time the timer 2
counter underflows is output from the TOUT pin. In this case, set the port P56 (this is used as the TOUT
pin) for the output mode.
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3820 GROUP USER’S MANUAL