AXIOMTEK MANO315 Series, Руководство пользователя

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MANO315 Mini ITX Motherboard
46 Watchdog Timer
Appendix A
Watchdog Timer
A.1 About Watchdog Timer
Software stability is major issue in most application. Some embedded systems are not
watched by human for 24 hours. It is usually too slow to wait for someone to reboot when
computer hangs. The systems need to be able to reset automatically when things go wrong.
The watchdog timer gives us solution.
The watchdog timer is a counter that triggers a system reset when it counts down to zero from
a preset value. The software starts counter with an initial value and must reset it periodically. If
the counter ever reaches zero which means the software has crashed, the system will reboot.
A.2 Watchdog Timer Programming
//**************************************************************
//** **
//** Copyright(C) 2018, Axiomtek co., Ltd **
//** **
//** All Rights Reserved. **
//** **
//**************************************************************
#include <pc.h>
#include <stdio.h>
#define SIO_Index_Port 0x2E
#define SIO_Data_Port 0x2F
#define SIO_Enter_Configuration_Mode 0x01
#define SIO_Entry_key 0x55
#define SIO_LDN_SEL_REGISTER 0x07
#define SIO_LogicalDevice_GPIO 0x07
#define SIO_Offset_Countdown_Type 0x72
#define SIO_Offset_Countdown_Timer 0x73
#define SIO_Countdown_Type_Second 0xC0
#define SIO_Countdown_Type_Minute 0x40
#define SIO_Exit_Configuration_Mode 0x02
void main() {
int CountdownType=0;
int WDTtimer=0;
printf("Input Watch Dog Timer type, 1:Second ; 2:Minute :");
scanf("%d",&CountdownType);
printf("\nInput Timer to countdown:");
scanf("%d",&WDTtimer);
printf("Start to countdown...");
//
// Enter Configuration Mode
//