FabiaTech FB2402, User Manual

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FabiaTech Corporation
56
Watchdog Timer Enabled
To enable the watchdog timer 0 (WDT 0), you have to output a byte of timer factor
to the watchdog register whose index address is 22h and data port is 23H. The
following is an Assemble program, which demonstrates how to enable the
watchdog timer and set the time-out period at 4 seconds.
;-----------------------------------------------
; Unlock Configuration Register
;-----------------------------------------------
Mov
dx,22h ; Enter to extended function mode
Mov al,13h
Out dx,al
Mov dx,23h
Mov al,c5h
Out dx,al
;-----------------------------------
; Enabled Watch dog
;-----------------------------------
Mov al,37h
Mov dx,22h
Out
dx,al
Mov al,40h ;Index 37 Bit 6 set 1
Mov dx,23h
Out
dx,al
;-------------------------------------------
; Lock Configuration Register
;-------------------------------------------
Mov dx,22h ;Exit the extended function mode
Mov al,13h
Out dx,al
Mov dx,23h
Mov al,00h
Out
dx,al