CHAPTER 7 INTERRUPTION/EXCEPTION PROCESSING FUNCTION
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User’s Manual U14359EJ4V0UM
Figure 7-4. Maskable Interrupt Servicing
INT input
xxIF = 1
No
xxMK = 0
No
Is the interrupt
mask released?
Yes
Yes
No
No
No
Maskable interrupt request
Interrupt request held pending
PSW.NP
PSW.ID
1
1
Interrupt request held pending
0
0
Interrupt servicing
CPU processing
INTC accepted
Yes
Yes
Yes
Priority higher than
that of interrupt currently
being serviced?
Priority higher
than that of other interrupt
request?
Highest default
priority of interrupt requests
with the same priority?
EIPC
EIPSW
ECR.EICC
PSW.EP
PSW.ID
Corresponding
bit of ISPR
Note
PC
Restored PC
PSW
Exception code
0
1
1
Handler address
Note
For the ISPR register, see
7.3.6 In-service priority register (ISPR)
.
The INT input masked by the interrupt controllers and the INT input that occurs while another interrupt is being
serviced (when PSW.NP = 1 or PSW.ID = 1) are held pending internally by the interrupt controller. In such case, if
the interrupts are unmasked, or when PSW.NP = 0 and PSW.ID = 0 as set by the RETI and LDSR instructions, input
of the pending INT starts the new maskable interrupt servicing.