The Discrete driver is responsible for providing an
interface to Discrete Input/Outputs. The capabilities provided
by this class of device driver are:
Initialize a Discrete I/O Board
Open a Particular Discrete Bitfield
Close a Particular Discrete Bitfield
Read from a Particular Discrete Bitfield
Write to a Particular Discrete Bitfield
Reset DACs
Reinitialize DACS
Most discrete I/O devices are found on I/O cards that support many
bits of discrete I/O on a single card. This driver model is centered
on the notion of reading bitfields from the card.
There are currently no discrete I/O device drivers included in the
RTEMS source tree. The information provided in this chapter
is based on drivers developed for applications using RTEMS.
It is hoped that this driver model information can form the
discrete I/O driver model that can be supported in future RTEMS
distribution.
BSP and Device Driver Development Guide