.\" Copyright (c) 1998,1999 Alex Nash
.\" All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\"	$OpenBSD: wdt.4,v 1.15 2007/05/31 19:19:55 jmc Exp $
.\"
.Dd $Mdocdate: May 31 2007 $
.Dt WDT 4 i386
.Os
.Sh NAME
.Nm wdt
.Nd ICS PCI-WDT500/501 watchdog timer device
.Sh SYNOPSIS
.Cd "wdt0 at pci?"
.Sh DESCRIPTION
The
.Nm
driver provides support for the Industrial Computer Source
PCI-WDT500 and PCI-WDT501 boards.
.Pp
For PCI-WDT500 boards, basic watchdog timer functionality is supported.
For PCI-WDT501 boards, the onboard buzzer will sound when the watchdog
counter expires.
The sensors are not yet supported.
.Pp
If the kernel crashes, the watchdog
timer is not reset and the system will reboot (assuming a proper connection
is made between the WDT50x and motherboard).
Alternatively, the watchdog
can be reinitialized via a userland process which ensures that process
scheduling, not just kernel timeout processing, is still taking place.
See
.Xr watchdog 4
and
.Xr watchdogd 8
for more information.
.Pp
The timer can be configured to have a timeout from 2 to 1800 seconds.
.Sh SEE ALSO
.Xr intro 4 ,
.Xr pci 4 ,
.Xr watchdog 4 ,
.Xr watchdogd 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Ox 2.6 .