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Altera_Forum's avatar
Altera_Forum
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17 years ago

Can the TX of Transceiver-A be routed to the RX of Transceiver-B internal to the FPGA

Hello,

This question is for both the Stratix II GX High Speed Serial Transceivers and the Stratix IV GX High Speed Serial Transceivers

Can the TX of Transceiver-A be routed to the RX of Transceiver-B internally to the FPGA?

Thank you for your help,

5 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    I'm sorry. I didn't read your initial post closely enough. You are correct. The loopback is only for a single transceiver.

    The circuitry does not physically exist to loop between transceiver channels within the FPGA.

    Jake
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    Doesn't the loopback feature only work within a single transceiver? What I want to do is go from one transceiver's TX to different tranceivers's RX inside the FPGA so that I can intercept the signal between the two with some programmable logic.

    Is that possible?

    Thanks again.
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    Yes. The transceivers support an internal loopback mode TX->RX. This is an option that you can set in the megawizard when creating your transceiver instance.

    Note however that there is no way to loop in the reverse direction (RX->TX).

    Jake
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    Hi,

    According to my experience with stratix II(not GX) the answer is no, since Rx needs LVDS inputs from pins.

    But I managed to do that in a wrapper testbench by connecting them externally and also looped back externally in actual hardware without problem.

    Kaz