Intel MB890 user manual C. Watchdog Timer Configuration

APPENDIX

C. Watchdog Timer Configuration

The WDT is used to generate a variety of output signals after a user programmable count. The WDT is suitable for use in the prevention of system lock-up, such as when software becomes trapped in a deadlock. Under these sort of circumstances, the timer will count to zero and the selected outputs will be driven. Under normal circumstance, the user will restart the WDT at regular intervals before the timer counts to zero.

SAMPLE CODE:

This code and information is provided "as is" without warranty of any kind, either expressed or implied, including but not limited to the implied warranties of merchantability and/or fitness for a particular purpose.

;[]================================================

; Name	: Enable_And_Set_Watchdog
; IN	: AL - 1sec ~ 255sec

;OUT : None ;[]================================================ Enable_And_Set_Watchdog Proc Near

push ax	;save time interval
call Unlock_Chip
mov cl, 2Bh
call Read_Reg
and al, NOT 10h
call Write_Reg	;set GP24 as WDTO
mov cl, 07h
mov al, 08h
call Write_Reg	;switch to LD8

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