Design Of Multi-Channel Data Acquisition System Based On FPGA And USB2.0Bus

This paper for the requirements of Tower Crane safety early-warning system， primarilystudies and designs a kind of Multi-channel data acquisition system based on the technologyof FPGA and USB2.0Bus, which is used to acquire,transmit and analyse the ultrasonicechoes of obstacles detecting.The system composed of HOST and Acquisition Board，the separation，storage andanalysis of multi-channel data is realized by the HOST.FPGA is used as control core of theAcquisition Board, in charger of the whole data acquisition hardwares control, realizes theacquisition and transmission of multi-channel real-time signal parallel processing. USB2.0Bus realizes the data communication between the data Acquisition Board and HOST.In the aspect of hardware，this paper design the acquisition control circuit based onFPGA，front-end data acquisition circuit of ADC LTC1609，SDRAM ping-pong buffer circuitand USB FX2LP interface circuit etc.In the aspect of USB2.0Bus，this paper analyse the working principle and framework ofFX2LP’s firmware, designs a USB communication interface which satisfied the USB2.0high-speed protocol.In the aspect of FPGA controlling modules，The FPGA is housed on each of themodules，which consists of Multi-channel data acquisition module,data Ping-pong buffermodule, USB data transmission module，HOST command decoding module. Data acquisitionmodule regulates the sample rate to sample the analog data after the signal is filtered andmagnified. Ping-pong buffer module takes charge of caching the sample data and then USBdata transmission module will transport them to the data bus of FX2LP according to thetiming of FX2LP. HOST command decoding module decodes the control command fromHOST，and then control the data acquisition hardwares.This Paper uses the ModelSim simulation tool to simulate the timing of sub-modules andtest the result of the Data acquisition and control on the real hardwares.The test results provethat this design satisfies the system requirements.