Lanner IAC-H671 Series, User Manual

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Appendix A Watch-Dog Timer
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User’s Manual
APPENDIXA. Watch-Dog Timer
You can enable the watch-dog when your application software monitors an unexpected or not respond,
then the timer generates a reset to reboot your system. During the period of enable to reset, you
could still cancel reset by disabling the watch-dog. Decide the way you want to set the period for
reset by selecting hardware or software watch-dog (if both of them are available). Software setting
period, normally setting watch-dog timer period to 16 levels.
Software watch-dog using example
EX.1: For DOS
Enable Disable
C:\DOS> DEBUG C:\DOS>DEBUG
-o443 D - o441 F
EX.2: For assemble Language
Enable : Disable :
MOV DX, 443H MOV DX, 441H
MOV AL, 0FH MOV AL, 0FH
OUT DX, AL OUT DX, AL
Note: “F” is the period of software watch-dog timer (normally “F” indicated 0 sec.). 0 to 9 and A
to F are used for represent different period. Normally, the step is 2 sec. That means “E” is
2, “D” is 4, “2” is 26, “1” is 28 and “0” is 30 seconds.