Programming the Watchdog Timer
To program the watchdog timer, you must write a program which writes I/O port address 443 (hex). The output data is a time interval value. The value range is from 01 (hex) to 3F (hex), and the related time interval is from 1 sec. to 63 sec.
Data | Time Interval |
01 | 1 sec. |
02 | 2 sec. |
03 | 3 sec. |
04 | 4 sec. |
• | • |
• | • |
• | • |
3F | 63 sec. |
After data entry, your program must refresh the watchdog timer by rewriting the I/O port 443 (hex) while simultaneously setting it. When you want to disable the watchdog timer, your program should read I/O port 443 (hex).
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