NEC PD750008 - Manual (Page 227)

207
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 same
instruction), 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 to
start the interrupt service program for INTT0, which has been held.
Reset
<2> RETI
<INT0 service program>
<1>
EI IET0
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
••
<Main program>
INT0
INTT0
EI IE0
EI
RETI
<INTT0 service routine>