32186 datasheet(141/1032 Pages) RENESAS

141 / 1032 page

INTERRUPT CONTROLLER (ICU)

5-17

32185/32186 Group Hardware Manual

Rev.1.10 REJ09B0235-0110 May 15, 07

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 detection of a falling edge on the SBI# signal input pin no matter how the PSW register IE bit is set,

and cannot be masked. If falling edge is inputted to SBI# pin again, system break is not occured while SBI

request bit is set to "1."

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

32186 Datasheet(PDF) 141 Page - Renesas Technology Corp