AUTOSAR Architecture

AUTOSAR Architecture

Hello all , AUTOSAR stands for AUTomotive Open System Architecture. Autosar architecture is an open source layered software architecture this mainly used automotive Electronic Control Unit(ECU) software development.

AUTOSAR gives a layered top-down structure for software with the relation between the software components.

Autosar Architecture is divided into 3 core layers

1.BSW(basic software )

2.RTE(Runtime Environment)

3.Application/Software Component layer.

The main concept of the standardized ECU software Autosar architecture is the separation of hardware-independent application software and hardware-oriented basic software (BSW) by means of the software abstraction layer RTE (runtime environment). On the upper side of the RTE, this abstraction layer enables the development of OEM-specific and competitive software applications. On the lower side of the RTE, it enables the standardization and OEM-independence of basic software. Further characteristics of the AUTOSAR architecture are the scalability of ECU software for several car lines and variants, the possibility to distribute applications (functional software modules) across ECUs, and the ability to integrate software modules from different sources.

The basic software within the AUTOSAR architecture is further divided into the following layers:

1.Services layers

2.ECU abstraction layers

3.Micro-controller abstraction layers

The separation of the application layer from the basic software, realized by the RTE, includes the control of the data exchange between these layers. This forms the basis for a component-oriented, hardware-independent software structure on the application level, with software components (SWCs) as individual units. Because of their hardware independence, it is thus possible to develop SWCs without specific knowledge of the hardware used or planned, as well as to flexibly relocate existing SWCs to ECUs during development.

Layers  Autosar Architecture

1.Services layers

Services layer is the highest layer of the Basic Software, mostly independent of the microcontroller hardware, responsible for providing the basic BSW functionality to the application software.

Main functions:

• Operating system functionality

• Vehicle network communication and management service

• Memory service (NVRM management )

• Diagnostic Service

• ECU state management ,mode management

Ect

Task: Provided basic service for application ,RTE and Basic software modules

Properties :

Implementation is uC and ECU independent.

2.ECU abstraction layers

ECU Abstraction Layer is the layer above the MCAL layer which houses the interface components.It mainly contains drivers for external devices.

It offers an API for access to peripheral and devices regardless of their location and their connection to the uC  the drivers for the hardware components outside the micro-controller on the ECU. Its basic responsibility is to make the layer above it independent of the hardware available on the ECU. Its lower interfaces are hardware dependent and the upper interfaces are hardware independent.

Task: Make higher software layers independent of ECU hardware layout.

Properties :

Implementation is uC independent  ,ECU hardware dependent

Upper interface is standardised and uC and ECU hardware independent .

3.Micro-controller abstraction layers

Micro-controller Abastraction layer(MCAL) is the lowest layer in the layered AUTOSAR architecture.

It contains internal drivers, which are software modules with direct access to the uC and internal peripherals, it communicates with the hardware directly. Its basic responsibility is to make the layer above it independent of hardware.

Task: Make higher software layers independent of micro controller .

Properties :

Implementation is uC dependent

Upper interface is standardised and uC independent .