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Altera_Forum
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16 years ago

DE2 Audio Codec Programming

Hi,

I am engg student.I are working on SOPC baesd speech to text conversion.I am confused with how to to program audio codec for Audio to Digital conversion for input from microphone and give it to FPGA.

25 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    hi

    i test g00.. . clock_500 give data be g00 but how can i have input with LDATA & RDATA ??

    clock_500 get one data 24bit

    clock_500 is datasheet i2sound

    PLEASE help me
  • Altera_Forum's avatar
    Altera_Forum
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    I had a short look at this audio codec interface, posted at the first page.

    It seems, bbcount indirectly controls the 48kpulse and produces someting like:

    f = 48kHz = "CLK" / 10 / 50 -> "CLK" = 500 * 48kHz = 24 MHz

    Therefore one could change this easily, adapting the counters. The only thing is the DAC information, which also hangs at this clock thing (?)

    I would recommend to rewrite it at least to something like this:

    (with " CLK / 10 / 50 equals CLK / 4 / 125")

    f* = 48kHz * 125 / 10 = 125/10 * "CLK" / 4 / 125

    and transform it to an "enable clock" running at 24MHz, obtaining 24 * 5 * 5 = 600MHz for the ALTPLL. Then you get

    IN 50 MHz * 12 = 600 MHz

    OUT 600 MHz / 25 / 125 = 24 MHz / 125 = 192 kHz
  • Altera_Forum's avatar
    Altera_Forum
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    Hi, I'm doing speech recognition system by using FPGA, anyone have source code about this project?

  • Altera_Forum's avatar
    Altera_Forum
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    You should better have asked that in a new thread.

    ... and provided some information what you need in detail.

    For those you intend to do AUDIO with a 50MHz OSC: There is a relation of MUL/DIV configuration of 57/14 for the PLL which can generate nearly exactly the 64 x Fs frequency = 12.288 which is the S/PDIF frequency. Some OSC tuning will help to synch to an external S/PDIF clock, such as generated by the AUDIO Codecs. I already made this real in some projects.