ELANSC(4) OpenBSD Programmer's Manual (i386) ELANSC(4)NAMEelansc - 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,
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 ALSOgpio(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 4.9 June 26, 2008 OpenBSD 4.9
