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DIR9001: DIR9001 Questions.

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Replies: 4

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Part Number: DIR9001

Hi Sir,

Pls kindly help for below questions for DIR9001, thanks.

  1. What different between PLL "lock" and "unlock"? How to switch between?
  2. AUDIO and EMPH are channel status, what function for these two pins?
  3. COUT, UOUT are LR clock of biphase input ?When will use these two pins?
  4. CLKST is necessary? Looks it will change follow PLL lock/unlock (active H), but "ERROR pin" can know PLL clock, is it?
  5. Most of DIR9001 pinout are o/p, what pins will need connect to SOC (ERROR, BFRAME, EMPH, COUT, UOUT, AUDIO, CLKST..)?

Thanks, Ian.

  • 1. A phase-locked loop circuit attempts to synchronize to the incoming S/PDIF data stream and recover data and clock from it. If the PLL cannot lock, it cannot recover the clock and data. You don't switch between these two states -- PLL lock is a status based. Put simply, if the PLL does not lock, you cannot use the received data as they are not valid.

    2. The S/PDIF decoder looks at status bits embedded in the recovered data stream (see the S/PDIF specification). EMPHASIS is used to indicate whether the audio data were encoded with a pre-emphasis filter. Also, S/PDIF can carry non-audio data packets. The AUDIO flag indicates whether it is receiving proper audio data or something else.

    3. COUT and UOUT are channel status and user status bits derived from the decoder, and they are clocked out with LRCLK. If you need those status bits they are available.

    4. CLKST is asserted when there is a change in PLL lock status. The data sheet tells you all about it.

    5. What pins you need to connect to your system processor depends on your application. You might wish to re-read the data sheet.

  • In reply to Andy Peters:

    Thanks Andy!

    Ian,

    I think Andy has you covered but let me know if you have any other questions!

    Best,

    Zak

    Regards,

    Zak Kaye
    Precision Data Converter Applications

  • In reply to Zak Kaye:

    Hi Guys,

    Some more questions, 

    1. BFRAME is detected in the received biphase signal?
    2. XTI mode is open drain? or need pull up?

    3. Reset default internal is pull up, if direct pull down if need reset?

    4. CLKST active H, is open drain?

    5. Why DOUT. DATA are MUTE under XT1?

    Thanks, Ian.

  • In reply to Ian Wang:

    Ian -- please read the data sheet more carefully. The answers are in there.