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vlfft for 6678 multicore FFT problem（no difference between 1core and 8cores）

xing wang
Intellectual 340 points
Other Parts Discussed in Thread: TMS320C6678

I've been trying a VLFFT project from China TI training forum to test the FFT performance of 6678. But following the user guide, I just got same results no matter how many cores I used to calculate.

3683.vlfft OK.zip

in the Vlfft ok.rar is the project I'm using.(make sure you use edma3_2_11_2_4 to build the project, higher version will cause cmd failures.) 

I

To configure the number of DSP cores to compute, open the file vlfftconfig.h under ...\demo\vlfft\vlfftInc and
change the constant definition NUM_CORES_FOR_FFT_COMPUTE to one of the following numbers
• 8-core device: 1, 2, 4, 8

But no matter which one I used, I just got 6.6ms result, and it was a 8 cores result.

Can any one tell me why? and Really appreciate if you can give me a hint.

Thanks

  • 0
    TI__Intellectual 1870 points

    Hi,

    It should work.  Could you please try the following?

    1) Compile the code in Debug mode

    2) On core0, set the breakpoint right after the function call vlfftParamsInit in vlfftApps.c.

    3) Check the following in the structure VLFFTparams.

       VLFFTparams->log2NumCoresForFftCompute 
       VLFFTparams->numCoresForFftCompute 
       VLFFTparams->N 
       VLFFTparams->N1
       VLFFTparams->N2

    Xiaohui

  • 0 in reply to Xiaohui Li
    Intellectual 385 points
    I have download the above code but when I compile the code, error message"STMHelper.c" not found and "com.ti.biosmcsdk.mcsdk is not recognized' is received.Kindly help me out how to resolve this issue
  • 0 in reply to Xiaohui Li
    Intellectual 385 points

    Hi,

    Xiaohui Li, I am working on your very large FFT code , I would like to know how you have measured the DSP cycles for  FFT performance table of your paper "Very large FFT for TMS320C6678 processors" .

    Regards