Image Processing Reference
In-Depth Information
Application layer
Application
software
System
software
AUTOSAR RTE
Input/output
substack
Communi-
cation
substack
Memory
substack
System
substack
Hardware
FIGURE .
AUTOSAR—system software substacks overview.
Communication substack
: The communication substack contains software modules that provide
standardized access to vehicle networks (i.e., the local interconnect network (LIN) [], the CAN
[,], and FlexRay [,]).
System service substack
: Last but not least, the system service substack encompasses all sotware mod-
ules that provide standardized (e.g., operating system, timer support, error loggers) and ECU-specific
(ECU state management, watchdog management) system services, and library functions.
Independent of the vertical and horizontal structuring, the following classification can be applied
to the AUTOSAR system software modules:
Drivers
: A driver contains the functionality to “control and access an internal or an external device.”
Hereby, internal devices, which are located within the microcontroller, are controlled by internal
drivers, whereas external devices, which are located on ECU hardware outside the microcontroller,
are controlled by external drivers. Internal drivers can usually be found within the microcontroller
abstraction layer, whereas external drivers are found in the ECU abstraction layer. Drivers do not
change the content of the data handed to them.
Interfaces
: An interface contains the functionality to “abstract from the hardware realization of a
specific device” and to provide a generic API to access a specific type of device independent of the
number of existing devices of that type and independent of the hardware realization of the different
devices. Interfaces are generally located within the ECU abstraction layer. Interfaces do not change
the content of the data handed to them.
Handlers
: A handler “controls the concurrent, multiple, and asynchronous accesses of one or more
clients”tooneormoredriverorinterfacemodules.hus,ahandlerperformsbufering,queuing,
arbitration, and multiplexing. Handlers do not change the content of the data handed to them.
Managers
: A manager offers specific services for multiple clients. Managers are required when-
ever pure handler functionality is insufficient for accessing and using interface and driver modules.
Managers furthermore are allowed to
evaluate and change or adapt the content of the data
handed to
them. Managers are usually located in the services layer.
In the following sections the different substacks of AUTOSAR system software modules are
described in detail.
