Image Processing Reference
In-Depth Information
Application
software
component
Application
software
component
Application
software
component
AUTOSAR RTE
ECU
abst.
Services
Comm.
Specific
drivers
OS
mctlr
abst.
ECU hardware
Standardized interfaces
FIGURE .
AUTOSAR reference architecture.
One of the main objectives of the AUTOSAR MW is to hide the characteristic of the hardware plat-
form as well as the distribution of the application software components. hus, the inter- or intra-ECU
communication services are of major importance and are thoroughly described in the documents
provided by the AUTOSAR consortium (see Figure . for an overview of the different modules).
The role of these services is crucial for the behavioral and temporal properties of an embedded and
distributed application. So, their design, their generation, and configuration have to be precisely
mastered and the verification of timing properties becomes an important activity. The problem is
complex because, as for the formerly mentioned MW the objects (e.g., signals, frames, I-PDU, etc.)
that are handled by services at one level are not the same objects that are handled by services at
another level. Nevertheless each object is strongly dependent of one or several objects handled by
services belonging to neighboring levels. The AUTOSAR standard proposes two communication
models:
•
“Sender-receiver” used for passing information between two application software com-
ponents (belonging to the same task, to two distinct tasks on the same ECU or to two
remote tasks)
•
“Client-server” that supports function invocation
Two communication modes are supported for the sender-receiver communication model:
•
“Explicit” mode is specified by a component that makes explicit calls to the AUTOSAR
MW for sending or receiving data.
•
“Implicit” mode means that the reading (resp. writing) of data is automatically done by the
MW before the invocation (resp. after the end of execution) of a component consuming
(resp. producing) the data without any explicit call to AUTOSAR services; this is away to
protect effectively the data between application software components and MW services.
