Acnodes FPC 7919 - Manual (Page 59)

661 Brea Canyon Rd., Suite 3
Walnut, CA 91789
tel: 909.598.7388, fax: 909.598.0218, www.acnodes.com
© Copyright 2009 Acnodes, Inc.
All rights reserved. Product description and product specifications
are subject to change without notice. For latest product information,
please visit Acnodes’ web site at www.acnodes.com.
FPC7919
Fanless 19-inch touch panel PC
Atom N270 1.6GHz all-in-one system
3.8 Watchdog Timer Configuration
The Watch-dog Timer has a programmable time-out ranging from 1 to 255 minutes with one minute
resolution, or 1 to 255 seconds with 1 second resolution. The units of the WDT timeout value are
selected via bit[7] of the WDT_TIMEOUT register, which is located on I/O Port address 0x865h. The
WDT time-out value is set through the WDT_VAL Runtime register, which is located on I/O Port
address 0x866h. Setting the WDT_VAL register to 0x00 disables the WDT function Setting the
WDT_VAL to any other non-zero value will cause the WDT to reload and begin counting down from the
value loaded. Setting the Register located on I/O address 0x867h and 0x868h as 00h to finish timer
configuration.
Example Program
Example Code: (1)
; ------------------------------------------------------------------------------------------------
; Enable Watch-Dog Timer
;-------------------------------------------------------------------------------------------------
mov dx, (800h+65h) ; Time counting Unit minute or second
mov al, 80h ; al = 00h : minute, or al = 80h : second
out dx, al
mov dx, (800h+66h)
mov al, 20 ; al = Watch Dog Timer Second (s) , 20 sec(s)
ou dx, al
mov dx, (800h+67h)
mov al, 00h
out dx, al
mov dx, (800h+68h) ; Start Watch Dog Timer
mov al, 00h
out dx, al
(2)
;--------------------------------------------------------------------------------------------------
; Disable Watch-Dog Timer
;--------------------------------------------------------------------------------------------------