FabiaTech FB2402, User Manual

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FabiaTech Corporation
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WDT1 setup Step:
1. Write time into register AAh-ACh.
2. Select signal from register A9h.
3. Set register A8h bit 8 to enable WDT1.
To clear the watchdog timer counter:
1. Write any value to register A7H
Watchdog Timer Enabled
To enable the watchdog timer 1 (WDT 1), you have to output a byte of timer factor
to the watchdog ports address is A8h. The following is an Assemble program, which
demonstrates how to enable the watchdog timer 1 and set the time-out period at
4 seconds.
;-----------------------------------
; Enabled Watch dog
;-----------------------------------
Mov al,40h
Mov dx,a8h ;IO port A8h Bit 6 set 1
Out dx,al
Watchdog Timer Trigger
;-------------------------
; Timer Counter
;-------------------------
Mov al,02h
Mov dx,aah ; IO port AAh set 02h = 4 sec
Out dx,al
;----------------------------------------
; Interrupt or System Reset
;----------------------------------------
Mov al,50h
;Trigger IRQ7
;Mov al,d0h ;System Reset
Mov dx,a9h ; IO port A9h Select Int, Reset, NMI signal
Out dx,al
;------------------------------------------------
; Trigger (Reset) Watchdog Timer
;------------------------------------------------
Or al,40h
Mov dx,aeh ; IO port AEh Trigger Watchdog
Out dx,al
Watchdog Timer Disabled
To disable the watchdog timer, simply write a 00H to the watchdog register.
;-----------------------------------
; Disabled Watchdog
;-----------------------------------
Mov al,40h ; IO port A8h disabled Watchdog
Mov dx,a8h
Out
dx,al