7733 datasheet(151/940 Pages) RENESAS

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TIMER A

7733 Group User’s Manual

6–40

[Precautions in one-shot pulse mode]

1. When the count start flag is cleared to “0” during counting, the followings are performed.

•The counter stops counting, and the reload register’s contents is reloaded.

•Pin TAiOUT’s output level becomes “L.”

•An interrupt request is generated, and a timer Ai interrupt request bit is set to “1.”

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

external trigger is selected, in the period from when a trigger is input to pin TAiIN until a one-shot pulse

is output, there will be a delay equivalent to one cycle of the count source at maximum.

6.5 One-shot pulse mode

Fig. 6.5.6 Delay in one-shot pulse output

3. When a timer’s operating mode is set by the procedure listed below, a timer Ai interrupt request bit is

set to “1.”

q When the one-shot pulse mode is selected after reset

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

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

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

request bit to “0” after setting the above.

g The above is applied when an external trigger (Falling edge of pin TAiIN’s input signal) is selected.

Pin TAiIN’s

input signal

“H”

“L”

Count

source

Trigger input

One-shot pulse output is started.

One-shot pulse

output from

pin TAiOUT

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