嵌入式系统设计报告英文含代码.doc

1.System Design Schema This system is called speech spectrum analyzer based on the development tools called TM320C6416. The software is tested on code composer studio 6416(CCS6416). The system can realize the function that It can analyse the spectrum of the speech signals inputted by fast fourier transform(FFT) algorithm, and then print the frequency by ergodic algorithm, which can help find the number of the maxmum magnitude location. In addition, the system also can paly the voice which was recoded before. The C6X is used to designate a member of Texas Instruments’ (TI) TMS320C6000 family of digital signal processors. The architecture of the C6x digital signal processor is very well suited for numerically intensive calculations. The FFT with the radix-2 algorithm is a efficient algorithm that is used for converting a time-domain signal into an equivalent frequency-domine signal , based on the discrete frouier transform(DFT), The FFT reduces considerably the computational requirements of the DFT. The DFT of a discrete-time signal x(nT) is  The FFT algorithm takes advantage of the periodicity and symmetry of the twiddle constants to reduce the computational requirements of the FFT. From the periodicity of W, and from the symmetry of W An eight-point FFT is illustrated through the following exercise. We will see that flow graphs for higher-order FFT (larger N) can readily be obtained. figure1. Eight-point FFT flow graph using DIT For the reason that the speech signals recognition is quite hard ,so 512-point FFT has been adopted. After FFT algorithm finished, 512 magnitudes will be acquired. Then the maximum value will be found by the ergodic algorithm, and we can get the accurate frequency by the equation of , and then print it in CCS. Besides, I have set many flags to identify whether the frequency belongs to high frequency, or low frequency by the way of the LED turning on. 2.Goal and Test Level of the system Achieved The system can record the voice in surroundin