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Altera_Forum's avatar
Altera_Forum
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17 years ago

Problem with AD/DA Conversion

Hello,

I'm trying to design a simple Project to understand the use of my Stratix II 2S60. This project is a AD/DA converter.

I display a counter 0-F on an LED, transfer it via my DAC to my ADC (a cable from DAC to ADC) and want to display the transferred number on the second LED of the Board.

I didn't find the error.

Could anybody help me?

I packed the project into a rar file-->

9 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    Hi,

    You will need to make sure that the two devices are synchronised to the correct number system and you don't violate their speed(Fs). The encoding of codecs is not linear(if you are using thier ADC)
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    i need a simple design and OFDM using QPSK , need help urgent please

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    --- Quote Start ---

    i need a simple design and OFDM using QPSK , need help urgent please

    --- Quote End ---

    You seem lucky. There was just a thread today on a simple ofdm, go fetch it...

    As DA/AD also note any filters could affect the conversion, you better disable them.
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    If you are using Stratix II DSP Dev Kit (most likely), it has AC-coupled DAC and ADC, your test doesn't work there. Use the example designs provided with the Dev Kit to check DAC/ADC operation.

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    Is it possible to make this testing program work? Or is it useless trying to make this thing work?

    If no, which variables/etc do I have to change?

    I'm trying to understand the AD/DA Conversion because I want to realize an FIR Filter. So I want to know what comes in and what goes out (and in which data format etc)

    Thanks
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    The AC-coupling (by RF transformers) implies, that you can only transmit high frequency signals with Dev Kits DAC and ADC. You could modify the hardware to make it DC capable, but this would also reduce the signal-noise ratio. The example design uses an NCO to generate a high frequency signal to be send and received.

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    According to me you use the example designs provided with the Dev Kit to check DAC/ADC operation.

  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    sorry, which example can test the ADC/DAC??

    As i can't find any inside the folder kits
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    The Stratix II DSP Dev. Kit. User Manula tells:

    --- Quote Start ---

    In the Quartus II software, open the sines project at <path>\StratixII_DSP_Kit-v6.0.1\Examples\<board name>\FactoryDesign\sines.qpf where <path> is the directory where the DSP Development Kit, Stratix II Edition Version 6.0.1 CD-ROM is installed.

    --- Quote End ---