User`s guide

I/O Overview
Input/Output Overview and Pipes 6-3
Device drivers are software modules that manage a class of devices. For
example, two common classes are serial ports and parallel ports. These
modules follow a common interface (provided by DEV) so stream functions
can make generic requests, the drivers execute in whatever manner is
appropriate for the particular class of devices.
Figure 6-2 depicts the interaction between streams and devices. The shaded
area illustrates the material covered by this chapter: the stream portion of this
interaction, handled by the SIO module. Chapter 7 discusses the DEV
module and the relationship of streams with devices.
Figure 6-2. Interaction Between Streams and Devices
Data pipes are used to buffer streams of input and output data. These data
pipes provide a consistent software data structure you can use to drive I/O
between the DSP device and all kinds of real-time peripheral devices. There is
more overhead with a data pipe than with streams, and notification is
automatically handled by the pipe manager. All I/O operations on a pipe deal
with one frame at a time; although each frame has a fixed length, the application
can put a variable amount of data in each frame up to the length of the frame.
HWI
Driver
Application
Device
SIO
DEV