7702 datasheet(126/217 Pages) RENESAS

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TIMER A

7702/7703 Group User’s Manual

5–38

5.5 One-shot pulse mode

[Precautions when operating in one-shot pulse mode]

1. If the count start bit is cleared to “0” during counting, the counter stops counting and the reload register’s

contents are reloaded into the counter, and the TAiOUT pin’s output level becomes “L.” At the same time,

the timer Ai interrupt request bit is set to “1.”

2. A one-shot pulse is output synchronously with an internally generated count source. Accordingly, when

selecting an external trigger, there will be a delay equivalent to one cycle of count source at maximum

from when a trigger is input to the TAiIN pin till when a one-shot pulse is output.

Fig. 5.5.6 Output delay in one-shot pulse output

3. When setting the timer’s operating mode in one of the followings, the timer Ai interrupt request bit is set

to “1.”

qWhen the one-shot pulse mode is selected after a reset

qWhen the operating mode is switched from the timer mode to the one-shot pulse mode

qWhen the operating mode is switched from the event counter mode to the one-shot pulse mode

Therefore, when using the timer Ai interrupt (interrupt request bit), be sure to clear the timer Ai interrupt

request bit to “0” after above setting.

4. Do not set “000016” to the timer Ai register.

Note: The above applies when an external trigger (falling of TAiIN pin’s input signal) is selected.

TAiIN pin’s

input signal

“H”

“L”

Count

source

Trigger input

Starts outputting of one-shot pulse

One-shot pulse

output from

TAiOUT pin

Output delay

7702 Datasheet(PDF) 126 Page - Renesas Technology Corp