Design And Implementation Of Audio Frequency Spectrum Analysis System Based On Avalon Bus

With the development of electronic and communication technology,digital audio processing technology,such as digital audio broadcasting and multimedia communication,has been widely used in the society and has a profound impact on people's life.At present,the real time and accuracy of the instruments on the market need to be improved,and there are not many kinds of tuners available.Based on Avalon bus technology and fast Fourier transform algorithm in FPGA,a real-time and efficient audio frequency spectrum analysis system is designed to realize the spectrum analysis function of music signal.The main work and research contents of this dissertation are as follows:1.Introduced the principle of fast Fourier transform algorithm,Nios II system and spectrum analysis,and analyzed the interface type and functional characteristics of Avalon bus.2.System hardware design.The function of the spectrum analysis display system is planned,and the system hardware circuit design scheme is given.The minimum system module of Cyclone IV E series FPGA chip is adopted,and the hardware framework of the system is composed of audio signal acquisition and decoding module and spectrum display module.Minimum system module includes power supply circuit and clock circuit,the FPGA configuration module USES a JTAG configuration circuit,audio codec circuit including acquisition circuit and AD circuit,audio spectrum display module USES is 5 inch capacitive touch screen.3.System software design.The general flow chart of software is given according to the system function.On the basis of the Avalon bus,realized the configuration interface timing module,the module of function such as FFT module,display module,completed the higher input signal receiving buffer in the FPGA software module,signal FFT processing and touch-screen display audio spectrum module design.On the basis of constructing PLL IP core,FIFO IP core,RAM IP core and FFT IP core,a Nios II system was built using Avalon bus.4.System software and hardware debugging and function simulation.After complete the hardware circuit and software code,first of all,the hardware circuit module was tested,and then use the Modelsim simulation software and the testing software part,logic analyzer test method is to write the test script interface timing module,FFT module,WM8731 module,audio spectrum display module function simulation,and the test results are analyzed.This system can complete a variety of music signal acquisition and real-time analysis,overcome the limit of traditional single tuner function,can be tuned for a variety of Musical Instruments,greatly improving the efficiency of the instrument of intonation and tuner,and has a certain practical value.