ZT5515A-1BW Intel, ZT5515A-1BW Datasheet - Page 44

• Manufacturer Part Number: ZT5515A-1BW
• Manufacturer: Intel

Specifications of ZT5515A-1BW

• Lead Free Status / Rohs Status: Supplier Unconfirmed

Watchdog Timer
8.2.2
8.2.2.1
44
Watchdog NMI
When enabled, an NMI precedes a watchdog reset by 250 ms. The NMI generation feature gives an
application 250 ms to perform essential tasks before the hardware is reset. Before using watchdog
NMI, ensure the following:
Chaining the ISRs
Save the original NMI ISR vector so that it can be invoked from the new watchdog NMI ISR. Alter
the interrupt vector table so that the NMI ISR vector is overwritten with a vector to the watchdog
ISR. C code to do this in DOS might look like the following:
#de
void interrupt far (*OldNmiIsr)();
//
// To be absolutely certain the interrupt table is not accessed by an
// NMI (this is quite unlikely), the application could disable NMI in
// the chip set before installing the new vector.
//
.
.
.
//
// Install the new ISR.
//
oldNmiIsr = getvect(IsrVector);
setvect(NMI_INTERRUPT_VECTOR_NUMBER, WatchdogIsr);// Install the new.
}
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fine NMI_INTERRUPT_VECTOR_NUMBER 2
Intel
The essential task code is included in an interrupt service routine (ISR).
The ISR is chained to the existing NMI ISR.
The watchdog NMI is enabled.
void HookWatchdogIsr(void){
®
NetStructure
TM
ZT 5515 Compute Processor Board Technical Product Specification
// Save the old vector.