Nmi Handler - Intel NetStructure ZT 5515 Product Specification

Watchdog Timer
8.2.2.3
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NMI Handler

Because an NMI may originate from a source such as a RAM Error Correction Code (ECC) error,
the NMI handler cannot assume that an NMI occurred due to a watchdog timeout. Therefore, the
NMI handler must check the watchdog status register before taking watchdog-related emergency
action. When the NMI handler completes handling the emergency, it invokes the original NMI
Handler (discussed above). The code to do this might look like the following:
#defin
e WD_NMI_DETECT_BIT_SET 0x40 // Bit indicates an NMI occurred, set.
void WatchdogIsr(void){
if(inb(WD_CSR_IO_ADDRESS) & WD_NMI_DETECT_BIT_SET){
TripAlarm();
TurnOffTheGas();
}
_chain_intr(OldNmiIsr);
}
®
TM
Intel NetStructure ZT 5515 Compute Processor Board Technical Product Specification
//
//
//
//
// Did the watchdog cause the NMI?
//
//
// Take care of essential tasks.
//
//
//
// Invoke the originally installed ISR.