使用FFT变换求一个时域信号的频域特性，并从这个频域特性求出该信号的频域值，使用DSP汇编语言实现对FFT的DSP编程-FFT transform the use of a time-domain signals in the frequency domain characteristics, and from the frequency domain characteristics of the signal obtained in the frequency domain value, the use of DSP assembly language to achieve FFT DSP programming