Portwell WADE-8156, User Manual

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WADE-8156 User’s Manual
Appendix A: Watchdog Timer Programming
The Watchdog Timer (WDT) is a special hardware device that monitors the computer
system during normal operation. The WDT has a clock circuit that times down from a set
number to zero. If a monitored item occurs be ore that timer reaches zero, the WDT resets
and counts down again. If for some reason the monitored item doesn’t occur before the
timer reaches zero, the WDT performs an action, such as a diagnostic operation (rebooting
the computer) or generate an NMI.
f
Watchdog Configuration
Address Port: 2Eh Data Port: 2Fh Description
87h na Enter Key
87h na Enter Key
07h 08h Setup Watch Dog Function
2Dh 20h Setup Watch Dog Function
30h 01h Enable Wa h Dog Function tc
F5h 00h 00h: select second mode, 08h: select minute mode
F6h 00h
Time-out occurs after 0~255 second/minute, 00h: Time-out
disable
anguage
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Ex ple
1. outportb(0x2e,0x87);
outportb(0x2e,0x87);
outportb(0x2e,0x07);
4. outportb(0x2f,0x08);
5. outportb(0x2e,0x2d);
6. outportb(0x2f,0x20);
7. outportb(0x2e,0x30);
8. outportb(0x2f,0x01);
9. outportb(0x2e,0xf5)
10. outportb(0x2f,0x00)
11. outportb(0x2e,0xf6);
12. outportb(0x2f,0x05);
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C L am :
2.
3.
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