Wafer-lx – IEI Integration WAFER-LX v1.0 User Manual

Page 117

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WAFER-LX

out period that is selected by software, please refer to the example program.

A tolerance of at least 5% must be maintained to avoid unknown routines within the operating

system (DOS), such as disk I/Os that can be very time consuming. Therefore, if the timeout

period has been set to 10 seconds, the I/O port 443H must be read within 7 seconds.

NOTE:

When exiting a program it is necessary to disable the Watchdog Timer,

otherwise the system will reset.

Example Assembly Program:

TIMER_PORT = 443H

TIMER_START = 443H

TIMER_STOP = 843H

;;INITIAL TIME PERIOD COUNTER

MOV DX, TIME_PORT

MOV AL, 8: ;;8 SECONDS

OUT DX, AL

;;ADD YOUR APPLICATION HERE

MOV DX, TIMER START

IN AL, DX. ;;START COUNTER

ADD YOUR APPLICATION HERE

W_LOOP:

MOV DX, TIMER_START

IN AL, DX. ;RESTART COUNTER

;ADD YOUR APPLICATION HERE

CMP EXIT_AP, 0

JNEW_LOOP

MOV DX, TIMER_STOP

A-3

A-3

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