NAME    [Toc]    [Back]

     elansc - AMD Elan SC520 System Controller driver

SYNOPSIS    [Toc]    [Back]

     elansc* at pci? dev ? function ?
     gpio* at elansc?

DESCRIPTION    [Toc]    [Back]

     The elansc driver supports the system controller of the  AMD
Elan SC520
     microcontroller.   The  SC520 consists of an AMD Am5x86 processor core, integrated
 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 following
 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 period.


     +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    [Toc]    [Back]

     geodesc(4), gpio(4), intro(4), gpioctl(8), sysctl(8)

HISTORY    [Toc]    [Back]

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

AUTHORS    [Toc]    [Back]

     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      3.6                          August     11,     2002