NEC PD78058FY(A) - Manual (Page 500)

500
CHAPTER 21 INTERRUPT AND TEST FUNCTIONS
Main Processing INTxx
Servicing INTyy
Servicing
INTxx
(PR=0)
1 Instruction
Execution
IE=0
INTyy
(PR=0)
IE=0
RETI
RETI
EI
Example 3 Example of a multiple interrupt not being generated because an interrupt was not permitted.
In processing of interrupt INTxx, interrupt reception was not permitted (the IE command was not
issued), so interrupt request INTyy was not received and multiple interrupts were not generated.
Interrupt request INTyy was held and received after 1 main processing command was executed.
PR = 0 : High Priority Order Level
IE = 0 : Interrupt Request Reception Prohibited