On Construction And Development Technology Of Vehicle MOST Network

Automotive electronic control technology and automotive network technologyare interdependent and promote each other. In recent years, with the demand ofautomotive electronic control increasing, both of them have been developedrapidly. At present, the CAN bus and LIN bus have been widely used in the actualvehicle. As TTCAN bus and FlexRay bus have high transmission rate andperformance they have been got attention by engineering and academic, becomingthe important development trend of future vehicle bus. But above buses are limitedto their own technical characteristics and transmission rate, so they are mainlyused in control, diagnostic and services. And then, MOST bus exhibits manyadvantages in automotive multimedia systems which have large amounts ofaudio/video streaming data to be transferred. MOST bus is a kind of ring networkwhich uses optical fiber or twisted pair as transmission medium. Moreover, it hasmany advantages, for example, having strong anti-interference, being able totransmit audio/video streaming data, asynchronous data and control datasimultaneously, supporting transmission rate up to150Mbit/s and so on.This dissertation focuses on the technology of MOST network. First, in orderto have a comprehensive and in-depth understanding of the MOST network, itsnetwork topology, functional relationship between nodes, multi-layer model,application layer framework, network protocol and network management etc, areanalyzed. Secondly, According to the characteristics of MOST network in datatransmission, the design scheme of MOST network which consists of audio nodeand video node is put forward. On the basis of choosing INIC as MOST network’sinterface controller, the connection mode and design thought of each node’shardware circuit are proposed aiming at nodes’ different functions and their owncharacteristics. Also, interactive port messages between INIC and EHC areanalyzed. Meanwhile, software design of two nodes is introduced. At last, in orderto verify the feasibility of audio node, the network being composed of OptolyzerOL3025o, audio node and Audio Interface is constructed. Then, based on thisnetwork, some communication tests are made such as setting logical address,establishing streaming data channel and connecting streaming data channel. Beforemaking network tests the I2C interface driver circuit, MOST network interfacecircuit and the other modular circuits of audio node are tested to ensure hardwarecircuit’s effectiveness, at the same time, the test problems and correspondingsolutions are discussed, also, the design requirements of device parameters are presented.