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TMD320C6657 DFSP_sp_ifftSPxSP Function

Kwon Seol
Prodigy 40 points

Hello.

I'm trying to float type ifft function.

but I can't understand some parameter.

what is brev, n_min.

In Reference just mentioned brev is pointer to bit reverse table containning 64 entries and n_min mentioned should be 4 if N can be represented as Power of 4 else, n_min should be 2.

but I can't understand about that.

follow is DSPF_sp_ifftSPxSP function's Reference.

Please your help

  • 0
    TI__Mastermind 25535 points

    Hi Kwon,

    Sorry for the late reply.

    Please mention the version of the DSPLIB you use.

    However when i looked into the version, dsplib_c66x_3_4_0_4, which I have,

    I could see the corresponding .c files, where the function is defined as well as the example programs in folder like....C:\ti\dsplib_c66x_3_4_0_4\examples

    In the example programs, please check for the function code which calls this function; where it passes the appropriate parameters appropriately

    So that, we will get more details about the usage.

    Through the examples, you can also port those project files into CCS and keep running on boards to test the library functions. This step will give more clarity when you pull the variabless in the CCS debug window and observe the outputs.

    Regards

    Shankari

  • 0 in reply to Shankari G
    Prodigy 40 points

    Hi Shankari G

    Thank you for your reply.

    I already read the example code.

    but I can't understand about what is brev factor and calculate process.

  • 0 in reply to Kwon Seol
    TI__Mastermind 25535 points

    HI Kwon,

    To understand the calculation process, Please visit these manuals which explains about the implementations.

    https://www.ti.com/lit/an/spracn4/spracn4.pdf

    https://www.ti.com/lit/an/spra291/spra291.pdf

    To understand the example, 

    1. Please read the concept / Algorithm of Fast Fourier Transform

    2. Knowledge in C language, so that you can do a code walk through and co-relate how the algorithm is implemented in C.

    Regars