NEC PD78052 User Manual page 505

Example 3. A multiple interrupt is not generated because interrupt is disabled
Because interrupts are disabled during interrupt INTxx servicing (EI instruction is not issued), interrupt request
INTyy is not acknowledged, and a multiple interrupt is not generated. INTyy request is reserved and acknowledged
after execution of one main processing instruction.
PR = 0 : High priority level
IE = 0 : Interrupt request acknowledgment disabled
CHAPTER 21 INTERRUPT AND TEST FUNCTIONS
Figure 21-16. Multiple Interrupt Example (2/2)
Main Processing
IE=0
EI
INTyy
(PR=0)
INTxx
(PR=0)
IE=0
1 Instruction
Execution
INTxx INTyy
Servicing Servicing
RETI
RETI
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