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INTERRUPT CONTROLLER (ICU)
32180 Group User’s Manual (Rev.1.0)
5.6 Description of System Break Interrupt (SBI) Operation
5.6.1 Acceptance of SBI
System Break Interrupt (SBI) is an emergency interrupt which is used when power outage is detected or a fault
condition is notified by an external watchdog timer. The system break interrupt is accepted anytime upon detec-
tion of a falling edge on the SBI# signal input pin no matter how the PSW register IE bit is set, and cannot be
masked.
5.6.2 SBI Processing by Handler
When the system break interrupt generated has been serviced, shut down or reset the system without returning
to the program that was being executed when the interrupt occurred.
5.6 Description of System Break Interrupt (SBI) Operation
Figure 5.6.1 Typical SBI Operation
H'0000 0010
BRA instruction
SBI (System Break Interrupt)
handler
SBI (System Break Interrupt)
vector entry
Program being
executed
SBI generated
Processing to shut
down the system
(Note 1)
Note 1: Do not return to the program that was being executed when the interrupt occurred.
Shut down or
reset the system
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