M16C62_M Datasheet, PDF (353/615 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES

Timer A
Mitsubishi microcomputers
M16C / 62A Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
2.2.15 Precautions for Timer A (one-shot timer mode)
(1) At reset, the count start flag is set to “0”. Set a value in the timer Ai register, then set the flag
to “1”.
(2) Setting the count start flag to “0” while a count is in progress causes as follows:
• The counter stops counting and a content of reload register is reloaded.
• The TAiOUT pin outputs “L” level.
• The interrupt request generated and the timer Ai interrupt request bit goes to “1”.
(3) The output from the one-shot timer synchronizes with the count source generated internally.
Therefore, when an external trigger has been selected, a delay of one cycle of the maximum
count source occurs between the trigger input to the TAiIN pin and the one-shot timer output.
(4) The timer Ai interrupt request bit goes to “1” if the timer's operation mode is set using any of
the following procedures:
• Selecting one-shot timer mode after reset.
• Changing operation mode from timer mode to one-shot timer mode.
• Changing operation mode from event counter mode to one-shot timer mode.
Therefore, to use timer Ai interrupt (interrupt request bit), set timer Ai interrupt request bit to
“0” after the above listed changes have been made.
(5) If a trigger occurs while a count is in progress, after the counter performs one down count
following the reoccurrence of a trigger, the reload register contents are reloaded, and the
count continues. To generate a trigger while a count is in progress, generate the second
trigger after an elapse longer than one cycle of the timer's count source after the previous
trigger occurred.
TAiIN pin input signal ^{“H”}
“L”
Count source
One-shot pulse
output from TAiOUT pin
Trigger input
Start one-shot pulse output
Note: The above applies when an external trigger (falling edge of TAiIN pin input signal) is selected.
Figure 2.2.31. One-shot timer delay
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