Problem regarding fft32x32.asm program

Brajesh,

Can you let us know what code you are refering to here? Is this code from the C64x+ DSPLIB ? I tried to replicate the problem that you are seeing but don`t see any issue with that function. Try this code with your function and let me know if you see the same output.

Here is the code

 int main()
{
   int i;
   int w[32],y[32];
   int x[32]= {1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0};
     
    gen_twiddle_fft32x32(w,16,2147483647.5);
    DSP_fft32x32(w,16,x,y);
    for ( i= 0;i<32;i=i+2){
     printf("FFT sample %d: %d+ i %d\n", i/2, y[i],y[i+1]);
    }
    printf("FFT done");
    return (1);
}

You should observe the following output with this function

FFT sample 0: 16+ i 0
FFT sample 1: 0+ i 0
FFT sample 2: 0+ i 0
FFT sample 3: 0+ i 0
FFT sample 4: 0+ i 0
FFT sample 5: 0+ i 0
FFT sample 6: 0+ i 0
FFT sample 7: 0+ i 0
FFT sample 8: 0+ i 0
FFT sample 9: 0+ i 0
FFT sample 10: 0+ i 0
FFT sample 11: 0+ i 0
FFT sample 12: 0+ i 0
FFT sample 13: 0+ i 0
FFT sample 14: 0+ i 0
FFT sample 15: 0+ i 0
FFT done

Which is exactly what you expect from the code isn`t it? If you can share your test code we will be able to tell you exactly what you need to do to get the correct output.

Regards,

Rahul

Hi

I am not using  C64x+ DSPLIB code. I got the code from the following link http://focus.ti.com/dsp/docs/dspplatformscontento.tsp?sectionId=2&familyId=1635&tabId=2432 This code contain SPLOOP ,SPKERNEL and it is different from the DSP_fft32x32  .The code is working fine with 64 or more points FFT but is is not working for 16 points FFT.

i am using TMS320C6474 processor.I have attached the fft32x32.asm code.

1033.fft32x32.zip

Brajesh,

If you are using the C6474 platform, I will advice you to use the 32 bit FFT function from the C64x+ DSPLIB. This library also contains a source driver project that you can use as sample code. In the meantime I will take a look at the code that you obtained from the above link and will report this if I can replicate the issue that you are seeing.

Thanks and Regards,

Rahul