Design And Research Of Virtual Instrument Based On USB3.0

With the deeper integration of computer,network,electronic testing and bus technology,ground-breaking revolution has occurred in the field of instrument,and virtual instrument technology comes into being.Nowadays,the virtual instrument has been the mainstream with the idea of "software means instrument",and it is leading the development direction in instrument field.By modifying the software of the virtual instrument system,the user can get the required function of instrument.After years of development,a variety of bus-based virtual instruments have appeared one after another.Since the universal serial bus(USB)has many advantages,such as high transmission speed,strong expansibility,hot swap supportable,low cost and so on,the virtual instrument based on USB will have a broad prospects for development and application.Since the widely-used USB2.0 data transmission system cannot meet the higher requirements of the high-capacity storage and testing system,the design and research on virtual instrument based on USB3.0 bus are put forward under the condition of a certain understanding of the USB3.0 protocol.After comparing,CYUSB3014 is selected as the protocol chip of USB3.0 interface,and its internal structures and working principles are explained,and then the EP3C40F484(a low-cost FPGA)is chosen as the master controller to achieve data acquisition and storage,as well as data transmission to the computer via the USB3.0 interface.In the design of hardware,the overall scheme is planned first,and then the FPGA control module,DDR2 SDRAM data cache module and USB3.0 transmission module circuit design are introduced emphatically.In the design of system software,FPGA program,FX3 firmware program and host computer software are introduced and designed.As for FPGA program design,the implementation method for ping-pong double-buffering of dual-chip DDR2 is introduced,and the focus is on the design of the USB3.0 controller based on FPGA,whichcan achieve reading and writing dates synchronously on the Slave FIFO mode of GPIF II interface;in design of FX3 firmware program,the main design is the GPIF II state machine,and all kinds of parameter for the firmware program is configured;and then based on the foundation of Visual Studio 2010 and the previous design,desired functions can be achieved by using C# language to add the appropriate code and revise application.Finally,USB3.0 interface performance is tested,which shows the interface speeds can reach up to 160MB/s.To verify the basic functions of virtual instrument based on USB3.0,the simulation experiments are conducted by acquiring and storing data of the specific waveform of signal source,then using host computer to read and showing data to compare with signal source.