7906 datasheet(101/531 Pages) RENESAS

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7906 Group User’s Manual Rev.2.0

INTERRUPTS

6-22

6.10 External interrupts

6.10.3 Switching of INTi to interrupt request occurrence factor

When the INTi interrupt request occurrence factor is switched in one of the following ways, there is a

possibility that the corresponding interrupt request bit is set to “1”:

• Switching the factor from the level sense to the edge sense

• Switching the polarity

Therefore, after this switching, make sure to clear the corresponding interrupt request bit to “0.” Figure

6.10.6 shows an example of the switching procedure for the INTi interrupt request’s occurrence factor.

Fig. 6.10.6 Example of switching procedure for INTi interrupt request’s occurrence factor

Set the interrupt priority level to one of

levels 1–7

or clear the interrupt disable flag (I) to “0.”

(INTi interrupt request is acceptable.)

Set the interrupt priority level to one of

levels 1–7

or clear the interrupt disable flag (I) to “0.”

(INTi interrupt request is acceptable.)

Clear the level sense/Edge sense select bit to “0.”

(Edge sense is selected.)

Clear the interrupt request bit to “0.”

Set the polarity select bit.

Clear the interrupt request bit to “0.”

(2) Switching the polarity

(1) Switching the factor from the level sense

to the edge sense

Set the interrupt priority level to 0

or set the interrupt disable flag (I) to “1.”

(INTi interrupt is disabled.)

Note: The above settings must be done separately.

Multiple settings must not be done at the same time, in other words, they must not be

done only by 1 instruction.

Set the interrupt priority level to 0

or set the interrupt disable flag (I) to “1.”

(INTi interrupt is disabled.)

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