ELANSC(4)             OpenBSD Programmer's Manual (i386)             ELANSC(4)

NAME
     elansc - AMD Elan SC520 System Controller with watchdog timer and GPIO

SYNOPSIS
     elansc* at pci?
     gpio* at elansc?

DESCRIPTION
     The elansc driver supports the system controller of the AMD Elan SC520
     microcontroller.  The SC520 consists of an AMD Am5x86 processor core, in-
     tegrated PCI host controller, and several standard on-chip devices, such
     as NS16550-compatible UARTs, real-time clock, and timers.

     The Elan SC520 also provides several special on-chip devices.  The fol-
     lowing are supported by the elansc driver:

     o   Watchdog timer.  The watchdog timer may be configured for a 1 second,
         2 second, 4 second, 8 second, 16 second, or 32 second expiration pe-
         riod.

     o   Programmable Input/Output.  The SC520 microcontroller supports 32
         programmable I/O signals (PIOs) that can be used on the system board
         to monitor signals or control devices that are not handled by the
         other functions in the SC520 microcontroller.  These signals can be
         programmed to be inputs or to be driven out ``high'' or ``low'' as
         outputs.  Pins can be accessed through the gpio(4) framework.  The
         gpioctl(8) program allows easy manipulation of pins from userland.

SEE ALSO
     gpio(4), intro(4), watchdog(4), gpioctl(8), sysctl(8)

HISTORY
     Support for the elansc was added in OpenBSD 3.3.  PIO function support
     appeared in OpenBSD 3.6.

AUTHORS
     The elansc driver was written by Jason R. Thorpe <thorpej@netbsd.org>.
     Jasper Wallace provided the work-around for a hardware bug related to the
     watchdog timer in some steppings of the SC520 CPU.  Alexander Yurchenko
     <grange@openbsd.org> added support for the PIO function.

OpenBSD 4.7                      June 26, 2008                               1
