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CHAPTER 6 INTERRUPT AND TEST FUNCTIONS
(5) Execution of held interrupts – two interrupts with lower priority occur concurrently –<1> When INT0 and INTT0 with the lower priority occur concurrently (during execution of the sameinstruction), INT0, with a higher priority, is executed first. (INTT0 is held.)<2> When the INT0 interrupt service program has been executed, the RETI instruction is executed tostart the interrupt service program for INTT0, which has been held.

Reset

<2> RETI

<INT0 service program>

<1>

EI IET0

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<Main program>

INT0

INTT0

EI IE0

EI

RETI

<INTT0 service routine>