Question about fetchdt.h

• 25 Oktober 2011 9:28

   

   
  

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  Hi!

  I'm trying to implement reduced clock operation and trying to understand fetchdt.h.

  I have some questions

  1. in body of FetchDMADataTouchDownSampled44, there is already "downsample from 40MHz to 20MHz" (below code)

  Is it already implement half-clock operation? If not, what is purpose of this part?

      // Downsample from 40MHz to 20MHz
      // Mem2VcsL and Mem2VcsH work together to downsample sequential 2 signal block into one signal block
      Mem2VcsL(*(SignalBlock*)p40MStream , block[0], block[1], block[2], block[3]);  // vcs is  4 complex16 samples
      Mem2VcsH(*((SignalBlock*)p40MStream + 1), block[3], block[4], block[5], block[6]);
      return hr;  // return S_OK if succed

  thanks!

   

  2. in body of resampler.resample ( in 44Mto40M.h ), it use LinearTableR, LinearTableL for downsampling 44M to 40M.

    What is mean of LinearTableR(and L)? What's mean of value of element in LinearTableR?

    I want to implement half-clock operation, than should I change this LinearTableR?

  3. in Mem2VcsH fuctio, what is mean of m128FirstHalfMask and ~0 which is an element in m128FirstHalfMask? (in fetchdt.h)

  • Diedit oleh ByungKeon Ko 27 Oktober 2011 5:05
  • Diedit oleh ByungKeon Ko 27 Oktober 2011 6:39
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