Interrupt Request Enabled For Multiple Interrupt During Interrupt Servicing - NEC PD78056F User Manual

Table 21-4. Interrupt Request Enabled for Multiple Interrupt During Interrupt Servicing
Interrupt Currently
Being Processed
Non-maskable interrupt
Maskable interrupt
Software interrupt
Remarks 1. E : Multiple interrupt enable
2. D : Multiple interrupt disable
3. ISP and IE are the flags contained in PSW
4. PR is a flag contained in PR0L, PR0H, and PR1L
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CHAPTER 21 INTERRUPT AND TEST FUNCTIONS
Multiple Interrupt
Non-maskable
Request
Interrupt
Request
D
ISP=0 E
ISP=1 E
E
ISP=0 : An interrupt with higher priority is being serviced
ISP=1 : An interrupt request is not accepted or an interrupt with lower priority is
being serviced
IE=0 : Interrupt request acknowledge is disabled
IE=1 : Interrupt request acknowledge is enabled
PR=0 : Higher priority level
PR=1 : Lower priority level
Maskable Interrupt Request
PR = 0 PR = 1
IE = 1 IE = 0 IE = 1
D D D
E D D
E D E
E D E
IE = 0
D
D
D
D