1, the characteristics of the USB bus (1)data transmission (2) data transfer rate data transmission (3) articulated a number of USB devices (4) USB interface for the device power supply (5) hot-swappable USB also has some new features such as: real-time communication between the real-time (can be achieved and a device), dynamic (dynamic switching between interfaces), joint (different interfaces can have similar characteristics together) pluripotency (different interfaces can use different modes of supply).

2, the structure of the USB interface and a typical application the USB interface pin definitions. USB interface data transmission distance is not greater than 5 meters. USB bus data transfer control of transmission, synchronous transfer, interrupt transfer, and block data transfer. USB HO the ST according to take an external USB device speed and the use of the characteristics of different data transmission characteristics such as control transfer to change the keyboard, mouse properties, interrupt transmission requirements of the keyboard, mouse input data; to change the Display Properties control transfer block data transfer will want to display the data to send to the monitor.