USB完全参考，协议、通信帧、电气、OTG等-USB Complete Reference

讲述了USB数据流模型、USB电气特性(缩写)、 协议层、USB设备架构、usb主机硬件软件以及集线器规范等-About the USB data flow model, USB Electrical Characteristics (abbreviation), protocol layer, USB device framework, usb hub host hardware, software and standardization

USB2.0总线协议标准，英文版，内容包括物理接口定义，总线协议，电气标准等；-USB2.0 bus protocol standard English, including physical interface definition, bus protocol, electrical standards

USB1.1总线协议标准，英文版，内容包括物理接口定义，总线协议，电气标准等；-USB1.1 bus protocol standard English, including physical interface definition, bus protocol, electrical standards