Software Component Development

The development of AUTOSAR software components in ASCET can be done using two approaches: the top-down approach and the bottom-up approach. This topic contains only a short description; see section Approaches for Creating Software Components in the ASCETV6.4 AUTOSAR User Guide for more information.

Top-Down Approach

In the top-down approach, the creation of an AUTOSAR software component is done in two steps:

In the first step, the interface of the component is defined. The interface is specified in an AUTOSAR authoring tool and exchanged via ARXML. The ARXML files are then given to a component API generator, which transforms the interface description into a header file. As a rule, the component API generator is the contract phase part of an RTE generator.
In a second step, the ARXML files are imported in ASCET, and the internal behavior is provided in terms of ASCET models that access the SWC and its interfaces. From these, C code is generated for the software components. The *.h and the *.c files of the software components can then be compiled.

Importing ARXML files can be done via the normal import mechanism (see Importing from ARXML or A2L Files) or via the AUTOSAR to ASCET importer (see Using the AUTOSAR to ASCET Converter).

The ARXML files contain usage information (e.g., access information for data elements and operation usage information) for the interface elements in the runnables.

Access information for a data element is stored using one of the Closed following keywords with additional information on the port and the data element name.

Operation usage information is stored using one of the Closed following keywords with additional information on the port and the operation name.

Prior to ASCET V6.4.7, this information was ignored by the ASCET to AUTOSAR importer. Since V6.4.7, this information is imported into ASCET. You can use the Use Imported ARXML Info option to determine the way ASCET uses the usage information from the ARXML file:

Use Imported ARXML Info value	Action
Ignore	Usage information from the ARXML file is ignored.
Match	Usage information from the ARXML file is compared with access information derived from the model.
DeriveAndMatch	Usage information from the ARXML file decides about access semantics prior to comparing it to the information derived from the model.

Usage Information from Imported ARXML Files contains details on using the information from the imported ARXML file.

Bottom-Up Approach

For single application software components, ASCET can be used as authoring tool and behavior modeling tool. In the bottom-up approach, the AUTOSAR modeling elements supported in ASCETV6.4, i.e. mode groups, AUTOSAR interfaces, software components, are created and maintained in the ASCET database/workspace.