Hi, i'm trying to use the DSP LIB to implement the FFT computation. I'm really confused by the twiddle generation function comes with the lib. I import the FFT_Example_66_LE_COFF example project. When i tried a 256 points FFT, i observed the twiddle generated by the function, gen_twiddle_fft16x32(w_16x32, N) for example. I found that only a few part of the arry w_16x32 have a meaningful value the rest of it are all zeros.
if you use the elf format .out file, this will be easy to get. But if you used the coff format .out file, the initial value of the arry are not zeros. You will have to watch the differences before and after the gen_twiddle_fft16x32(w_16x32, N) function runs, and still only a few part of the arry will change.
For more information, i exported the input and the output of the FFT function, and run FFT on Matlab, the result is totally different!
Waiting for answers, Thanks a lot!