通信论文远程USB光纤传输系统的研究与设计.doc

远程usb光纤传输系统的研究与设计 远程usb光纤传输系统的研究与设计 study and design of the remote usb optical fiber transmission system【中文摘要】 通用串行总线(usb)是一种新兴的计算机外围通信接口标准,随着计算机技术和数字技术的迅猛发展,以及usb 2.0、usb otg的推出,usb技术的应用日益广泛。usb具有灵活、方便、应用范围广、通信稳定、成本低廉等优点,已成为当前计算机必备的接口。但是其单段电缆几米、多级串联几十米的传输距离,始终是限制其应用范围进一步拓展的巨大障碍。因此,远程usb传输系统的开发具有重要意义。本文提出了一种利用光纤实现usb信号远距离透明传输的方案。它支持usb全速传输,在本地的主机一侧和远端的设备一侧分别添加一个光收发端机,中间通过一对单模光纤进行连接。本文对系统的硬件电路和fpga内核编程作了详细介绍,给出了各部分的电路原理图、verilog核心代码和调试结果,对系统调试和运行中出现的问题进行了分析,给出了解决问题和排除故障的方案。文末还对高速远程usb传输系统的设计提出了建议,并提出了后续工作的目标。【英文摘要】 universal serial bus (usb) is a newly-emerged computer peripheral communication interface standard. with the rapid development of computer and digital technology, and the evolution of usb 2.0 and usb otg specifications, the usb technology is becoming more widely used than ever before. usb has the advantage of flexibility, convenience, stability, broad application, and low cost. it has become a standard interface of computer nowadays. however, the transmission distance of usb is restricted to several meters on a single cable, and at most tens of meters even cascaded, which is a main obstacle that confines its application. therefore it becomes significant to development a remote usb transmission system.this thesis provides a solution that utilizes optical fiber to transparently transmit usb signals. it supports full-speed remote usb transmission by adding a pair of optical transceivers on both sides of local host and remote device, which are linked by a pair of single-mode optical fiber the hardware designing and software programming are introduced in detail. circuit scheme for each part of the system, kernel codes in verilog hdl, and debugging results are provided. malfunctions and failures during the debugging and running periods are analyzed, and solutions to existing problems are presented. suggestions to the upcoming work, which will support high-speed usb transmission, are given in the end. 【中文关键词】 通用串行总线(usb); 光纤传输; 远程传输; 现场可编程门阵列(fpga); verilog硬件描述语言(verilog hdl); 光收发端机 【英文关键词】 universal serial bus (usb); optical fiber transmission; remote transmission; field programmable gate array (fpga); verilog hardware description language; optical transceiver 【论文目录】摘要 4-5 abstract 5 1 绪论 14-16 1.1 问题的提出 14-15 1.2 设计目标与作者的主要工作 15 1.3 论文内容结构 15-16 2 usb 结构体系和电气规范 16-27 2.1 主机和设备 16-17 2.1.1 usb 主机 16-17 2.1.2 usb 设备 17 2.2 总线拓扑 17-18 2.3 usb 电缆 18-20 2.4 插锁型连接器协议 20-21 2.5 传输速率 21-22 2.6 信号特性 22-23 2.6.1 信号线状态 22 2.6.2 数据信号编码 22-23 2.6.3 位填充 23 2.6.4 信号传输顺序 23 2.7 传输类型 23-27 2.7.1 批量传输 24 2.7.2 控制传输 24 2.7.3 中断传输 24-25 2.7.4 同步传输 25 2.7.5 关于usb 数据传输类型的说明 25-27 3 usb 协议分析 27-41 3.1 usb 传输的基本单元包 27-37 3.1.1 包的组成字段 27-30 3.1.2 包的类型 30-37 3.2 事务处理 37-41 3.2.1 in 处理 37-39 3.2.2 out 处理 39 3.2.3 setup 处理 39-40 3.2.4 事务处理补充说明 40-41 4 远程usb 光纤传输系统结构及电路设计 41-54 4.1 系统结构 41-43 4.1.1 系统总体结构 41-42 4.1.2 光收发端机结构设计 42-43 4.2 usb 物理接口电路设计 43-47 4.2.1 芯片选型及介绍 43-46 4.2.2 周边电路设计 46-47 4.3 光收发模块电路设计 47-49 4.3.1 光模块选型及介绍 47-49 4.3.2 驱动电路设计 49 4.4 fpga 控制模块及配置电路设计 49-50 4.4.1 芯片选型及介绍 49-50 4.4.2 配置电路设计 50 4.5 供电模块及辅助电路设计 50-52 4.6 小结 52-54 5 控制模块fpga 内核设计 54-67 5.1 usb 包处理分析 54-59 5.1.1 setup 进程 55-56 5.1.2 in 进程 56-57 5.1.3 out 进程 57-59 5.2 fpga 内核设计 59-67 5.2.1 内核结构 59 5.2.2 协议逻辑模块的实现 59-66 5.2.3 usb 物