Fpga-based Signal Acquisition And Processing System Design And Realization

With the high-speed development of computer technology and chips' manufacture technics, data acquisition, processing and transmission, which are the three bases of Information Technique, hasten mutually. They promote the digital system to be much bulkier, smaller and speedier. Taking its notable advantages of agility, flexibility and reconfiguration, FPGA (Field Programmable Gate Array) makes this trend practical. Recently, it is popular to use the FPGA to design the digital system combining the high-speed ADC and mass storage SDRAM (Synchronous Dynamic Random Access Memory).The single FPGA chip acts as the control and processing core of the system.This dissertation utilized Xilinx's Virtex-4 FPGA as the platform to design and realize a 4-channel signal acquisition & processing system, it communicated with PC by USB (Universal Serial Bus)interface. The whole system mainly consisted of four parts: signal modulation module, multi-channel sampling module, data pre-processing module and data store control module. The first signal modulation module filtered and magnified the input signals. The second module then sampled the modulated signals with 12-bit parallel outputs. The sampling frequency was controlled by FPGA. The data pre-processing module first shift the samples and then implemented the FFT processing. The results were subsequently stored into the last module for further processing and verification. This thesis integrated the parallel pipelining and ping-pong operation in order to improve the precision and efficiency of FFT processor. It took about 10.24μs to complete the 1024-point FFT arithmetic of four channels' samples. Compared with the previous DSP processing scheme, the FPGA strategy improved the performance remarkably and reduced the cost greatly.Finally, this paper introduced the solution to the Signal Integrity of the high-speed circuit, designed and fabricated the PCB (Printed Circuit Board) of the signal modulation & acquisition circuit and the signal processing circuit. Furthermore, the necessary downloading and debugging were carried out on the circuit boards. The test results proved that the system satisfied the target requirements.