Research And Design On LED Large Screen Controller Based On Ethernet

LED large screen display system has characteristics of high brightness, low weight, high precision display location and so on, it takes a large proportion of application of large screen display and has become an integrant part of science and technology. Along with the further development of photovoltaic technology, media architecture has developed and motivates the development of LED screen in the gaint direction.The increasing speed of the network making all kinds of traditional transmissions were replaced by TCP/IP gradually, such as the Network Storage, video over IP. However, it needs high-end CPU to achieve a high-throughput. In recent years, people have begun to use the TCP/IP Offload Engine to solve the problem. But TOE is for high-end application mostly. If want to get a higher transmission speed in low-speed embedded system, TOE technology is also must be used.The project proposees a large screen control system based on TOE chip AX11015 targeted at the LED screen development motivated by media architecture. The project takes advantage of the hardware TOE technology and small embedded TCP/IP protocol , combines the embedded high-speed network and pixel control technology, and uses CPLD and SRAM to form large-capacity FIFO and some sequential logices by time division duplexing algorithm, achieved a LED large screen control system with low-cost and high-throughput.According to the requirements of the project, the whole system was divided into several functional modules which realized separately. The paper was divided into seven chapters and the design of project was expatiated in detail from many aspects. First introduced the background of the topic and raised the task, then proceed from the principle of LED darive, analysed the pixel drive technology and the request of control system formed by pixel driver. In the third charpter analysed the system principle on the overall structure, software and hardware and development tools. In hardware focus on the design of CPU and CPLD functional modules, and analysed the interface circuits in detailed. For software design, it mainly discussed the realization of high-speed embeeded TOE network, large-capacity FIFO, TDM algorithm and offline SD card system. Talked about the test form controller and whole system two aspedts in chapter six and gave the summary of the system design and the expectation for the follow-up design finally.In the paper studied and analysed the process of LED large screen net controller in detail and in depth from the aspect of project research and development and product, and designed the realization of every function modules, realized the design target in the aspect of theory. In full on the basis of the principle experiment, several design improvements, and repeated tests, completed the requirements of project design. Experiment results indicate that using UDP transport protocol, the throughput can be up to 20 Mbps which can transfer non-compressed video data smoothly. The control system works stable and the picture is showing clearly and smooth. At present, the project design has become products, and applyed in a number of projects which has achieved good economic results.