CHAPTER 6. INTERRUPT FUNCTIONS

(4) Pending interrupt execution

 

 

 

 

<Main Program>

 

<Main Program>

 

Reset

 

 

 

 

EI

IECSI

EI

IE0

EI

 

 

<INT0 Service Program>

 

 

 

INT0

INTCSI

RETI

<INTCSI Service Program>

RETI

If INT0 and INTCSI are generated simultaneously (during execution of the same instruction), INT0, which has the higher interrupt priority, is executed first (INTCSI is held pending).

When the INT0 service program is ended by the RETI instruction, the pending INTCSI service program is started.

140

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NEC PD75402A, PD75P402 user manual Pending interrupt execution, 140, INT0 Intcsi ➁ Reti