基于 USB 2·0／MAC 协议变换的延长系统设计

摘要

为克服通用串行总线（USB）在远程通信中的不稳定性和传输时延问题，延长 USB 接口的传输距离，提出一种修改和自定义的以太网 MAC 协议，并采用该协议与 USB 2·0协议之间的协议转换技术，建立一种基于 FPGA 的 USB 延长系统。数据由 USB 设备／主机传入 FPGA 中处理，通过 USB 2·0接口传至主机／USB 设备并作出响应，实现双向数据传输。结合 FPGA 和 Quartus II 软件平台完成设计验证，验证结果表明，该延长系统具有良好的可行性、稳定性和兼容性。%To overcome the instability and transmission delay problems of universal serial bus (USB)in communication,and to further extend the transmission distance of USB interface,an FPGA-based extension system was developed by using USB 2·0 and a modified and customized Ethernet MAC protocol conversion technology.The whole system and functional modules were designed according to the pro-tocol conversion principle.Data were transmitted from the USB devices/host to the FPGA for processing and then sent back to the host/USB devices via USB 2·0 interface and responded.The two-way data transmission was realized.The design verification completed by combining FPGA and Quartus II software platform proves the feasibility,stability and compatibility of the extension system.