NEC NEC PD78081(A), User Manual

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CHAPTER 12 INTERRUPT FUNCTION
Table 12-4. Interrupt Request Enabled for Multiple Interrupt during Interrupt Servicing
Maskable Interrupt Request
PR=0 PR=1
IE=1 IE=0 IE=1 IE=0
Non-maskable interrupt D D D D D
Maskable interrupt ISP=0 E E D D D
ISP=1 E E D E D
Software interrupt E E D E D
Remarks 1.
E : Multiple interrupt enable
2.
D : Multiple interrupt disable
3.
ISP and IE are the flags contained in PSW
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
4.
PR is a flag contained in PR0L, PR0H, and PR1L
PR=0 : Higher priority level
PR=1 : Lower priority level
Interrupt
during processing
Non-maskable
Interrupt
Request
Multiple Interrupt
Request