Watchdog Timer Enabled - FabiaTech FX5638 Series User Manual

FabiaTech Corporation

Watchdog Timer Enabled

To enable the watchdog timer, you have to output a byte of timer factor to the
watchdog register whose address is 2eh and data port is 2fH. The following is an
Assemble program, which demonstrates how to enable the watchdog timer and
set the time-out period at 28 seconds.
;------------------------------------------------------------------------------------------
; Enter the extended function mode
;------------------------------------------------------------------------------------------
Mov dx, 2eh
Mov al, 87h
Out dx,al
Nop
Nop
Mov al,01h
Out dx,al
Nop
Nop
Mov al,55h
Out dx,al
Nop
Nop
Mov al,55h
Out dx,al
Mov al,22
Out dx,al
Mov dx,2fh
Mov al,00h
Out dx,al
;--------------------------------------------------------------------------------------------------------------
; Logical device 7, configuration registers Index 72h-Bit 7, 73H (LSB)/74H (MSB)
;--------------------------------------------------------------------------------------------------------------
Mov dx,2fh
Mov al,07h
Out dx,al
Mov dx,2eh
Mov al,72h
Out dx,al
Mov dx,2fh
Or al,C0h
;Or al,40h
Out dx,al
Mov dx,2eh
Mov al,74h
Out dx,al
Mov dx,2fh
Mov al,00h
Out dx,al
Mov dx,2eh
Mov al,73h
Mov dx,2fh
; Enter to extended function mode
; Select Logical Device 7 of watchdog timer
;Index 72h- Time-Out Value and Watchdog Register
;Set Bit 7 is 1: Second and Bit6: Enabled Watchdog.
;Set Bit 7 is 0: Minute.
; Set Timer counter 0100~FF00 (MSB)
; Set Timer counter 0001~00FF (LSB)
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