NEC PD78054(A) User Manual

××

IF

:

Interrupt request flag

××

MK

:

Interrupt mask flag

××

PR

:

Priority specify flag

IE

:

Flag to control acknowledgment of maskable interrupt request (1 = enable, 0 = disable)

ISP

:

Flag to indicate the priority of interrupt currently being serviced (0 = servicing interrupt of high priority,

1 = not acknowledging interrupt request or servicing interrupt of low priority)

Start

× ×

 IF=1?

× ×

 MK=0?

× ×

 PR=0?

Any

Simultaneously

generated 

××

PR=0

interrupt requests?

Any

Simultaneously

generated high-priority

interrupt requests?

IE=1?

ISP=1?

Vectored interrupt
servicing

Interrupt request
reserve

Interrupt request
reserve

Interrupt request
reserve

Interrupt request
reserve

Interrupt request
reserve

Interrupt request
reserve

Interrupt request
reserve

Vectored interrupt
servicing

Any high-

priority interrupt request

among simultaneously generated

××

PR=0 interrupt

requests?

IE=1?

Yes (High priority)

Yes

No

Yes

No

No

No

Yes (Interrupt Request
        Generation)

No

Yes

No (Low Priority)

Yes

Yes

No

Yes

Yes

No

No