Introduction to AUTOSAR...

What is AUTOSAR ?

AUTOSAR stands for – Automotive Open Systems Architecture. It is a middleware and system-level standard, jointly developed by automobile manufacturers, electronics and software suppliers and tool vendors to facilitate portability, compatibility & integration of SW components over the lifetime of the vehicle. More than 100 members are part of this consortium.

Architecture

The Layered Software Architecture describes the software architecture of AUTOSAR. In AUTOSAR, the ECU software is abstracted and sub classified in three major parts-

1. BSW (Basic Software)
2. RTE (Run Time Environment)
3. Application layer/software.

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Let us explore all these layers in depth..

1. Basic Software - It is further divided into three sub-modules

   1. Microcontroller Abstraction layer - It is the lowest software layer of the Basic Software. It contains internal drivers, which are software modules with direct access to the µC and internal peripherals. Make higher software layers independent of µC and it is generally µC dependent.
   2. ECU Abstraction layer - It interfaces the drivers of the Microcontroller Abstraction Layer. It also contains drivers for external devices. It offers an API for access to peripherals and devices regardless of their location (µC internal/external) and their connection to the µC (port pins, type of interface). It is generally independent of ECU hardware layout.
   3. Services layer - It offers functionalities like : basic operating system functionality (OS is a part of this layer), vehicle network communication and management services, memory services, diagnostic Services (including UDS communication, error memory and fault treatment), ECU state management, mode management, logical and temporal program flow monitoring (Watch Dog manager).

2. Run Time Environment - It is a layer providing communication services to the application software (AUTOSAR Software Components and/or AUTOSAR Sensor/Actuator components). It makes AUTOSAR Software Components independent from the mapping to a specific ECU. It is generally ECU and application specific.

3. Application layer - It contains the SWC (Software Components) which realize the application functionality of the ECU. For example if the ECU is of Infotainment System then the SWC will consists of the applications related to that ECU performing application level functionalities. Different ECUs have specific SWCs which are ECUs independent.

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   NOTE- AUTOSAR is a very vast architecture. It is almost impossible to know everything. Still you can get the detailed knowledge on https://www.autosar.org/