Development Of EDSL Modem Based On SOPC

With the rapid development of Internet, the demand of broadband access technology is increased. The xDSL technology is widely accepted as the mainstream of broadband access technology because of the full usage of resources of twisted pair and high-speed channel for users. In January 2003, Ministry of Information Industry of China proposed the Ethernet Digital Subscriber Line System (TDD-EDSL) based on TDD, which combined the essence of two widely-used communication technology: xDSL and Ethernet. TDD-EDSL first realized the direct Transmission of IP pack in access network without conversion of ATM packt; it provides a new kind of high speed broadband access scheme and overcome many technical limitations of traditional xDSL technology.Traditional xDSL Modem system is usually made of embedded CPU or DSP processors and other subsystem components which have some disadvantages, such as complex equipment structure, high cost, poor flexibility, low integration, etc. Using the SOPC technology, the functions of DSP and RISC processor can be implemented on a single chip. Thanks to SOPC technology which combines the advantages both of SOC and FPGA, a complete system can be customized quickly, which can shorten the development cycle of designers and make the designing scheme flexible.The implementation of TDD-EDSL Modem base on SOPC technology is concerned in this paper.Firstly, xDSL broadband access technology was introduced this paper, especially on the basic principles and technical characteristics of TDD-EDSL and drawled a comparison between xDSL broadband access technology and the current mainsteam broadband ADSL in order to highlight its own advantages.Secondly, a design approach of TDD-EDSL Modem based on SOPC is presented in this disertation; and established a platform of Embedded System TDD-EDSL based on Nios II Soft Core processor; Main transceiver of TDD-EDSL Modem was implemented based on FPGA with Verilog HDL. It transplanted a realtime operating systemsμC/OS-II on embedded system with LwIP protocol embedded, which realized system control of terminal and system Communication.At last, most parts of the system are simulated.