NEC 78014Y Series User Manual page 463

Interrupt request
Interrupt request
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CHAPTER 18 INTERRUPT FUNCTIONS AND TEST FUNCTION
Figure 18-12. Interrupt Request Acknowledge Processing Algorithm
Interrupt request
reserve
Any high-
priority interrupt
Yes
among simultaneously
generated
interrupt requests?
reserve
No
IE = 1?
reserve
Vectored interrupt
servicing
××IF : Interrupt request flag
××MK : Interrupt mask flag
××PR : Priority specify flag
IE : Flag to control maskable interrupt request acknowledge (1 = Enable, 0 = Disable)
ISP : Flag to indicate the priority of interrupt being serviced (0 = Interrupt with high-priority is being
serviced, 1 = Interrupt request is not acknowledged or an Interrupt with low-priority is being
serviced)
No
No
Yes (High Priority)
××
PR = 0
No
Yes
Start
××
IF = 1?
Yes (Interrupt Request Generation)
××
MK = 0?
Yes
××
PR = 0?
No (Low Priority)
Any simul-
Yes
taneously generated
××
PR = 0 interrupt
requests?
Interrupt request
No
Any simul-
Yes
taneously generated
high-priority interrupt
requests?
Interrupt request
No
No
IE = 1?
Interrupt request
Yes
No
ISP = 1?
Interrupt request
Yes
Vectored interrupt
servicing
reserve
reserve
reserve
reserve
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