Civil Engineering Reference
In-Depth Information
Fig. 4.17
From model to implementation. (Elektrobit Automotive GmbH, AUTOSAR—RTE
User's Guide)
The requirements of the software components to their host environment are
described in a standardized formal format. This format, the software component
description, contains all information about the internal structure of the software
component: Communication ports are described with their interfaces as well as the
internal implementation details of the runtime parts. These runtime parts are called
runnable entities and part of the description is how they are executed respectively
by the event that triggers them. Trigger events can be set, e.g. by a cyclic clock or
by the reception of a signal (data-received event).
The goal of the RTE is to hide all lower software layers. As such RTE hides the
I/O driver layer and the communication layers as well as the access to the operating
system. The application developer shall not write source code with direct access
to counter, alarms and semaphores anymore. It is no longer necessary to define
tasks and control respectively configure the task activation in the OS configuration.
Instead, all runtime components of the applications will be represented by the run-
nable entities. It is the job of the RTE to manage all runnable entities, to map them
into OS tasks and hence to predefine parts of the OS configuration. With this ab-
straction, it is possible to design, develop and test application software components
