Arbor Technology EmETXe-i87M0, Руководство пользователя

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Appendix
Appendix D: Watchdog Timer (WDT) Setting
WDT is widely used for industry application to monitor the activity of CPU. Ap-
plication software depends on its requirement to trigger WDT with adequate
timer setting. Before WDT time out, the functional normal system will reload
the WDT. The WDT never time out for a normal system. The WDT will not be
reloaded by an abnormal system, then WDT will time out and reset the system
automatically to avoid abnormal operation.
This board supports 255 levels watchdog timer by software programming I/O
ports. Below are the source codes written in C, please take them as WDT ap-
plication example.
/*----- Include Header Area -----*/
#include “math.h”
#include “stdio.h”
#include “dos.h”
#define DELAY_TIME 10
int SMB_PORT_AD = 0xF040;
int SMB_DEVICE_ADD = 0x6e; /* 75111R’s Add=6eh */
unsigned char WDTCount;
void WDT_Start(void);
int WDT_Count(void);
unsigned char SMB_Byte_READ(int SMPORT, int DeviceID, int iREG_INDEX);
void SMB_Byte_WRITE(int SMPORT, int DeviceID, int oREG_INDEX, int oREG_DATA);
/*----- routing, sub-routing -----*/
void main()
{
unsigned char iCount;
printf(“WDT Times ( 1 ~ 127 ) : \0”);
scanf(“%d”,&WDTCount);
printf(“\n”);
WDT_Start();
while(1)
{
iCount = WDT_Count();
printf(“\r Counts : %d “,iCount);
delay(100000);
}
}
void WDT_Start(void)
{
unsigned char bData;