The â…¡R FPGA-based Digital Filter Design

First of all, according to the principle of digital filter and digital filter designmethod is analyzed, this article adopts the method of the distributed algorithmoptimization, distributed lookup table instead of computing the multiplier, but using alookup table data is large, the data transmission speed will have influence. Based on the16th order IIR low-pass digital filter as an example for grouping lookup table, including16order IIR low-pass digital filter of sampling frequency for2KHz, cutoff frequency of40hz, to determine the performance of the filter can get corresponding tap coefficient.Secondly, using the MATLAB simulation, through the MATLAB software todesign index parameters in the simulation, it use FDATOOL simulation tool ofMATLAB software, the filter parameter input to FDATOOL interface to get thedistribution of zero pole digital filter, amplitude frequency characteristic and phasefrequency characteristic curves, as well as to automatically generate the coefficient ofthe tap coefficient of the filter, in the FPGA simulation requirements of input data as aninteger, so to tap coefficient of the conversion of binary.Finally, on the basis of the FPGA design module of the whole, the total is dividedinto four modules, including the Filter module, LUT lookup table module, the additionof shift module, the top-level module, the whole system using VHDL languageprogramming, the various modules compiled chart of simulation, the simulation resultsto get the actual figure, to tap coefficient and the convolution operation to get the outputvalue of the theory of input, compare the theoretical value and practical value for theoutput of the Filter design theory and the output of the overall error of3, so the Filter ofthe overall design is reasonable and feasible.