NEC PD78081(A) User Manual page 213

Example 3. Example of when a multiple interrupt is not generated because interrupts are not enabled.
Because interrupts are not enabled (the EI instruction is not executed) during processing of interrupt
INTxx , interrupt request INTyy is not acknowledged and a multiple interrupt is not generated. Interrupt
request INTyy is reserved and acknowledged after one main processing instruction is implemented.
PR = 0 : High priority level
IE = 0 : Interrupt request acknowledge disabled.
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CHAPTER 12 INTERRUPT FUNCTION
Figure 12-14 Multiple Interrupt Example (2/2)
Main Processing
IE=0
EI
INTxx
(PR=0)
1 Instruction
Execution
INTxx INTyy
Servicing Servicing
INTyy
(PR=0)
RETI
IE=0
RETI