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WBWD(4)                FreeBSD Kernel Interfaces Manual                WBWD(4)

     wbwd - device driver for Winbond/Nuvoton Super I/O chips watchdog timer

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

           device wbwd

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


     The wbwd driver provides watchdog(4) support for the watchdog interrupt
     timer present on at least the following Super I/O chips:
        Winbond 83627HF/F/HG/G
        Winbond 83627S
        Winbond 83697HF
        Winbond 83697UG
        Winbond 83637HF
        Winbond 83627THF
        Winbond 83687THF
        Winbond 83627EHF
        Winbond 83627DHG
        Winbond 83627UHG
        Winbond 83667HG
        Winbond 83627DHG-P
        Winbond 83667HG-B
        Nuvoton NCT6775
        Nuvoton NCT6776
        Nuvoton NCT6102
        Nuvoton NCT6779
        Nuvoton NCT6791
        Nuvoton NCT6792

     Driver may be forced to attach to unknown chips by adding to

     The wbwd driver provides the following options as sysctl(8) variables.

             This variable allows to program the timer to a value independent
             on the one provided by the watchdog(4) framework while still
             relying on the regular updates from e.g.  watchdogd(8).  This is
             particularly useful if your system provides multiple watchdogs
             and you want them to fire in a special sequence to trigger an NMI
             after a shorter period than the reset timeout for example.  The
             value set must not be lower than the sleep time of watchdogd(8).
             A value of 0 disables this feature and the timeout value provided
             by watchdog(4) will be used.

             If set this sysctl will tell the driver to log its current state
             before and after the timer reset on each invocation from
             watchdog(9) to the kernel message buffer for debugging.

             This read-only value gives the state of some registers on last

     The wbwd driver also provides further sysctl options that are hidden by
     default.  See the source code for more information.

     watchdog(4), device.hints(5), watchdog(8), watchdogd(8), watchdog(9)

     The wbwd driver first appeared in FreeBSD 10.0.

     This manual page was written by Bjoern A. Zeeb <[email protected]>.

FreeBSD 11.1-RELEASE-p4         March 24, 2016         FreeBSD 11.1-RELEASE-p4
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