The Research For Data Acquisition System Based On FPGA And USB

With the rapid development of digital electronic technology, data acquisition (DAQ) has become very important in industrial production, and demands of data transmission for the high speed, reliability, real-time and handleability are constantly improved. Now, the data acquisition card has been applied to earthquakes, medical instruments, radar, communication, remote sensing etc. As a new type of bus interface standard, USB bus technology is widely applied to data acquisition system, which many advantages such as high-speed, plug and play, flexible, independent power supply etc. Meanwhile, the FPGA (Field-Programmable Gate Array) is suitable for the controller, because it is fast, flexible, the rich I/O resources, short development cycle. Therefore, using the FPGA design combined with USB to develop high speed data acquisition system becomes a trend.Taking full advantages of FPGA and USB mentioned above, data acquisition system based on FPGA and USB 2.0 is proposed in this paper. First of all, the development trend of data acquisition and processing system is introduced, and the feasibility and necessity of high-speed data acquisition system based on FPGA and USB is illuminated, and then the basic theory of data acquisition and the technology of system-related is introduced briefly. Secondly, the design of the whole system framework is given, each part of hardwares is designed and analyzed, and the corresponding schematic diagram is given on that basic.The design of the hardware mainly includes the FPGA and ADC (Analog to Digital Converter), FPGA and USB chip of the interface between circuits. Among them, TLC5510 of Texas appliances is adopted in A/D, and the pin function is introduced in detail; the FPGA chip of Altera is used for controlling the system; USB interface chip(CY7C68013A) of the Cypress is used for connecting with computer. Thirdly, according to the requirements of the system, the software of the system is designed, including the design of the FPGA logic, the design of USB firmware, the design of USB drive and the design of the application program. Finally, the hardware and the software of the system are debugged, given the debugging results and analysis. The results show that the system met the requirements of designing system and achieved the purpose of this research and design sucessfully.The system of basic workflow is: through the function signal generator produces the input signals, which are converted into the corresponding digital signals after ADC, then the digital signals are directly transferred to the FPGA controller. The digital signals are stored and processed by using FPGA controller and SDRAM storage circuit, and then the data is connected with the computer by using USB bus, and will be displayed on the computer.