Design And Research Of Automotive Gigabit Ethernet Switch Based On AVB

With the rapid development of electronic products in the field of networking and intelligence,electronic controllers in the automotive field have become more and more intelligent,and the bandwidth demand for in-vehicle networks has continued to increase.Various new car technologies have brought comfort,safety and intelligence to people,and the number of controllers in the car has increased rapidly,which has brought a burden to the bandwidth of the vehicle network.Especially in the field of car audio and video transmission,various audio and video transmission needs continue to increase,such as 360 surround system,ADAS system,active security system.With the 360 surround system as the scene design requirement,an automotive Gigabit Ethernet switch that satisfies the AVB protocol is designed.Through the research on the key technologies of the vehicle Ethernet switch and AVB,an automotive Gigabit Ethernet switch based on the 360 look-around system is designed.The switch supports the AVB protocol.The technology involved is described in detail first,including automotive Ethernet,switches,and AVB technology.Then with the uncompressed high-definition video transmission as the design requirement,the performance characteristics of the selected switch chip 88Q5050 and PHY chip 88Q2112 are introduced,and the system framework of the switch is built.The switch design uses two 88Q5050 switch chips and three 88Q2112 physical layer chips for audio and video data transmission for the Gigabit network module.Secondly,the switching chip and the hardware circuit of the PHY chip are described in detail,mainly from the interface circuit and power management.Finally,the built environment is tested and verified.The test results show that the verification result is expected to verify that the bandwidth of the switch platform meets the design requirements of Gigabit,and can support the requirements of flow reservation and queue forwarding protocol in the AVB protocol.In the process of audio and video transmission,the transmission of asynchronous data streams can be satisfied while preferentially ensuring audio and video transmission.The system design feature is equipped with the first automotive-grade 1000BASE-T1 Ethernet PHY chip 88Q2112 on the market,and combined with two switching chips to form a Gigabit Ethernet switch supporting AVB.It provides a reference for the on-board Ethernet network to move toward gigabit.