NEC PD754144 User Manual page 210

(6) Executing pending interrupt - interrupt occurs during interrupt service (INTBT has higher priority and
INTT0 and INTT2 have lower priority) -
EI
EI
EI
MOV A, #9
MOV IPS, A
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<1> If INTBT with a higher priority and INTT0 with a lower priority occur at the same time, the servicing of
the interrupt with the higher priority is started. (If there is no possibility that an interrupt with a higher
priority will occur while another interrupt with a higher priority is being serviced, DI IE×× is not necessary.)
<2> If an interrupt with a lower priority occurs while an interrupt with a higher priority is being executed, the
interrupt with the lower priority is held pending.
<3> When the interrupt with the higher priority has been serviced, INTT0 with the highest priority of the
pending interrupts is executed.
<4> When the servicing of INTT0 has been completed, the pending INTT2 is serviced.
210
CHAPTER 7 INTERRUPT AND TEST FUNCTIONS
<Main program>
Reset
IEBT
IET0
IET2
INTT0
<1>
INTBT
User's Manual U10676EJ3V0UM
<lNTBT servicing program>
PUSH rp
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INTT2
<2>
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POP rp
<3> RETI
<lNTT0 servicing program>
<4> RETI
<lNTT2 servicing program>
RETI