SBC comm SBC-350A ユーザーズマニュアル

Appendix A Programming the watchdog timer    39

Watchdog Timer Delay Values

(Hex)
0 ~ 2

E

16 ~ 18

6

2 ~ 4

D

18 ~ 20

5

4 ~ 6

C

20 ~ 22

4

6 ~ 8

B

22 ~ 24

3

8 ~ 10

A

24 ~ 26

2

10 ~ 12

9

26 ~ 28

1

12 ~ 14

8

28 ~ 30

0

14 ~ 16

7

The following demo program illustrates the programming steps
required to enable, set the time-out interval and disable the
watchdog timer.

#include<stdio.h> #include<dos.h> #include <conio.h> #include

<time.h> #include<graphics.h> void mydelay(void);

/* MAIN PROGRAM */ void main(void) {

 unsigned int  dog=0,

               run_time=0;

          char inkey;

 clrscr();

 gotoxy(15, 6);printf(“AAEON TECHNOLOGY, INC.”);

 gotoxy(15, 7);printf(“WATCHDOG TIMER TEST & DEMO

 PROGRAM”);

 gotoxy(15, 9);printf(“Please setup watchdog delay

 time:(2 Sec-30 Sec)”);

 /* Set watchdog timer time-out interval */

 scanf(“%2d”,&dog);

   /* Input watchdog timer time-

 out interval (Sec) */

 dog=dog/2;

   /* Convert time-out interval

 to designated Hex */

 dog=15-dog;

 outportb(0x443,dog);      /* Enable watchdog timer */

 /* Setup screen display format */

 gotoxy(15,11);printf(“Now enable watchdog!”);

 gotoxy(15,12);printf(“You can put keyboard reset or

 disable watchdog.”);

 gotoxy(15,13);printf(“    [1].Reset watchdog.”);

 gotoxy(15,14);printf(“    [2].Disable watchdog.”);

 gotoxy(15,15);printf(“    [3].Return to O.S.”);

 /* Read key pressed */