中文摘要 ABSTRACT 2 第一章引言 3 1.1USB技术 1.2项目来源及概述 第二章USB协议…5 2.1USB技术背景 2.2USB总线优势 2.2.USB的速度 6 2.2.2USB的总线拓扑体系 2.2.3USB的即插即用 9 2.2.4USB的低功耗 2.2.5USB的标准接口和外设 2.2.6结论 14 2.3USB软件通讯协议 2.3.1USB数据流 2.3.2USB数据单 16 2.3.2.1域 2.3.2.2 17 2.3.3USB总线传输 19 23.3.1控制传输( Control Transfer) 2332同步传输( sychronous transfer) 23.3.3批传输( Bulk transfer) 2334中断传输( Interrupt Transfer) 23.3.5结论 2.3.4数据触发同步与重试 26中文摘要......................................................................................................1 ABSTRACT.................................................................................................2 第一章 引言 ...............................................................................................3 1.1 USB 技术 .......................................................................................3 1.2 项目来源及概述.............................................................................3 第二章 USB 协议 ....................................................................................5 2.1 USB 技术背景 ................................................................................5 2.2 USB 总线优势 ................................................................................6 2.2.1 USB 的速度.................................................................................6 2.2.2 USB 的总线拓扑体系..................................................................7 2.2.3 USB 的即插即用 .........................................................................9 2.2.4 USB 的低功耗 ........................................................................... 11 2.2.5 USB 的标准接口和外设 ............................................................12 2.2.6 结论.......................................................................................14 2.3 USB 软件通讯协议 ......................................................................14 2.3.1 USB 数据流...............................................................................14 2.3.2 USB 数据单元 ...........................................................................16 2.3.2.1 域 .......................................................................................16 2.3.2.2 包 .......................................................................................17 2.3.3 USB 总线传输 ...........................................................................19 2.3.3.1 控制传输(Control Transfer) ................................................ 20 2.3.3.2 同步传输(Isochronous Transfer) ......................................... 22 2.3.3.3 批传输(Bulk Transfer)........................................................ 23 2.3.3.4 中断传输(Interrupt Transfer) .............................................. 24 2.3.3.5 结论 ...................................................................................25 2.3.4 数据触发同步与重试 ............................................................26