Research And Application On High Speed Data Transmission Technology Of USB3.0

With the rapid development of electronic and information technology, the data transmission interface is also constantly upgrading. USB is a serial bus standard, and an input and output interface specification, with features of high speed, stability, plug and play etc, which is widely applied to computer and mobile devices. USB3.0 has a dual bus structure, backward compatible with USB2.0, the maximum rate of speeding mode is up to 5.0Gbps, and it supports full duplex communication between host and device. Most storage test systems in our laboratory take USB2.0 as communication interface between computer and the test instrument, but with the emergence of mass storage test systems, higher interface rate is needed.On the basis of understanding USB3.0 protocol, a USB3.0 based high speed data transmission system is proposed and designed. By comparison of several USB3.0 chips, CYUSB3014 is finally chosen as the main control chip of the system. Design of the system follows principles of universality and reliability, which needs to consider factors such as electromagnetic compatibility, signal and power integrity, and improve the anti-interference ability of the system to ensure the rapid and accurate transmission of data.In the hardware design, Cadence is used as the tool to carry out schematic designing and PCB drawing. Circuit diagram and function realization of each module are introduced in detail. The system adopts 8 layers of PCB design, and multiple simulations are carried out before and after PCB wiring. Differential pairs design and eye diagram simulation are introduced in detail. Some measures of high speed interconnection between circuit boards are put forward. In terms of software design, the internal data transmission mechanism of CYUSB3014 is introduced firstly. Then, combining with the project design experience, the firmware programming and optimization are carried out, two methods of USB driver design are proposed. PC software are designed, and call of the dynamic link library is introduced.At last, application of the high speed data transmission system in the airborne data storage system is introduced, and the system performance is tested and verified. USB3.0 works in the Slave FIFO interface mode, the design of GPIF II state machine is introduced in detail. FPGA in the data recorder works as an external master controller. The clock and data buffer module are designed by calling the IP kernel, and the read timing is simulated. In this application, the rate of USB3.0 interface is up to 120MB/s, and the system works stably. Compared with the USB2.0 interface scheme, the USB3.0 interface has obvious advantages.