NAME

     ichwd — device driver for the Intel ICH watchdog interrupt timer

SYNOPSIS

     To compile this driver into the kernel, place the following line in your kernel
     configuration file:

           device ichwd

     Alternatively, to load the driver as a module at boot time, place the following line in
     loader.conf(5):

           ichwd_load="YES"

DESCRIPTION

     The ichwd driver provides watchdog(4) support for the watchdog interrupt timer present on
     all Intel ICH motherboard chipsets.

     The ICH WDT counts down in ticks of approximately 0.6 seconds; the exact value depends on
     hardware quality and environmental factors.  Supported watchdog intervals range from 2 to 63
     ticks.

     Note that on some ICH-based systems, the WDT may be present but disabled, either in hardware
     or by the BIOS.  The ichwd driver attempts to detect this condition and will refuse to
     attach if it believes the WDT is disabled.

SEE ALSO

     watchdog(4), watchdog(8), watchdogd(8), watchdog(9)

     Using the Intel ICH Family Watchdog Timer (WDT), Intel Application Note AP-725, Document
     Number 292273-001.

HISTORY

     The ichwd driver first appeared in FreeBSD 5.3.

AUTHORS

     The ichwd driver was written by Wm. Daryl Hawkins <dhawkins@tamu.edu> of Texas A&M
     University and Dag-Erling Smørgrav <des@FreeBSD.org>.  This manual page was written by
     Dag-Erling Smørgrav <des@FreeBSD.org>.