Device Driver Model Overview - Analog Devices VisualDSP++ 5.0 Service Manual

All sources to the device driver model are included in the various distribu-
tions of the model. While it is not expected that the sources will need to
be modified or tailored to any specific application, they are provided in
order for the user to fully understand how the code works.
The terms device manager and physical driver refer to the respective soft-
ware components. The term device driver refers to the combination of the
device driver manager (called device manager in this book) and physical
driver.

Device Driver Model Overview

The device driver model is built using a hierarchical approach.
Figure 10-1 illustrates the various components of the system design.
The components shown in the figure are:
• Application – Though typically the user's application, this block
can be any software component that can be thought of as a client of
the device manager. Note that the client does not have to be a sin-
gle functional block. The device manager can support any number
of clients. For example, a client may be a single-user application or
the client may be any number of tasks in RTOS-controlled
systems.
• RTOS – Some systems use the services of a real-time operating
system (RTOS). The device driver model is not tailored to a partic-
ular RTOS, nor does it require the presence of an RTOS. The
device driver model does not require any functionality or services
from an RTOS. Some real-time operating systems require that
applications go through the RTOS in order to access device drivers.
In these systems, the RTOS is simply viewed as a client to the
device manager.
VisualDSP++ 5.0 Device Drivers and System
Services Manual for Blackfin Processors
Device Driver Manager
10-3