INTERRUPT CONTROLLER (ICU)
5.6 Description of System Break Interrupt (SBI) Operation
5
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.
SBI (System Break Interrupt)
vector entry
BRA instruction
H'0000 0010
SBI (System Break Interrupt)
handler
Program being
executed
Processing to shut
down the system
(Note 1)
SBI generated
Shut down or
reset the system
Note 1: Do not return to the program that was being executed when the interrupt occurred.
Figure 5.6.1 Typical SBI Operation
32180 Group User’s Manual (Rev.1.0)
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RENESAS [ RENESAS TECHNOLOGY CORP ]
