Design And Application Of LVDS To Gigabit Ethernet Adapter

With the rapidly develop of our country's economy,the air pollution is becoming more and more severe,which makes protecting atmosphere a pressing issue.While in the governing of the atmosphere,monitoring the atmosphere is an important part.Our research group have been developing imaging spectrometers used for monitoring the atmosphere for a long time,and now we have a variety of products including satellite-borne imaging spectrometers and airborne imaging spectrometers.In order to test the imaging spectrometers more easily,with the feature that all the interfaces of the spectrometers are LVDS,LVDS to USB2.0 adapter?LVDS to USB3.0 adapter and LVDS to Gigabit Ethernet adapter are designed.Imaging spectrometers can be connected to PC or notebook through these adapters very easily,which increased the portability of the testing system.The main content of this paper is the design and application of the LVDS to Gigabit Ethernet adapter.There are three parts of this paper:The first part describes the research back ground and meaning of the LVDS to Gigabit Ethernet adapter,introduces some brief current research status of the imaging spectrometers data acquire system,introduces the history of the born and development of the Ethernet technology.And then introduces the OS I reference model and the TCP/IP protocol suite,and describes the details of the UDP?IP?ARP and Ethernet frame,including data packet format,the meaning of each data yield and the operation mode of each protocol.The second part mainly talks about the design of the LVDS to Gigabit Ethernet adapter,which consists of the design of the hardware logic of the adapter,the design of the hardware circuit and the design of the upper computer testing software.The whole hardware logical design of the adapter is divided into four different parts based on the differences of the functions,they are serial to parallel module,data buffering module,UART module and UDP/IP module.The functions of each model is described,and the problems we came up with during the design and the method of how to fix those problems are introduced.In the design of hardware circuit,we describe the power module circuit,FPGA circuit,MAC chip circuit,PHY chip circuit and the periphery interface circuit,and introduce the way to increase the quality of the signal.The upper computer test software is designed with C++ language,and use four modules to implement the different functions.The third part is about testing of the adapter,including functional test and performance test.The testing results show that the adapter can transmit the image data fast and steady,the highest data rate is 140Mbps and the bit error rate is 0.