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Serge93's avatar
Serge93
Icon for Occasional Contributor rankOccasional Contributor
3 months ago
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AGILEX 5E : GTS AXI IP PCI Express : What is the mapping of the PCIe Header on _tuser_hdr[255:0]

Hello,

In AGILEX 5E : GTS AXI Streaming IP for PCI Express user guide : ug-813754-855610.pdf

What is the mapping of the PCIe Header on "_tuser_hdr[255:0]" signal when the PCIe0/1 AXI-ST Sideband Header parameter is enabled.

We have the mapping for the Tdata signal but not for the _tuser_hdr[255:0] signal.

Is it the same mapping ?

Thank you.
Serge

  • Wincent_Altera's avatar
    Wincent_Altera
    3 months ago

    Hi @Serge93 ,

    The header format for inband and sideband is the same, thus we do not have a separate set of definition for sideband header.
    We will include this information more explicit in our next IP UG version.

    Regards,
    Wincent_Altera

6 Replies

  • Wincent_Altera's avatar
    Wincent_Altera
    Icon for Regular Contributor rankRegular Contributor
    3 months ago

    Hi Serge,

    Based on my understanding, The mapping of the fields in _tuser_hdr is NOT the same as the mapping in tdata. tdata contains the actual TLP data (including header and payload),

    the _tuser_hdr contains just the header and sideband fields (if I not mistaked), in a format defined by Altera for easier access to header information.

    • The mapping of _tuser_hdr[255:0] is usually (For real cases, I suggest check the example design or simulation)
      [127:0] = PCIe TLP Header (DW0-DW3, 32 bits each)
      [255:128] = Sideband signals or reserved

    Regards,
    Wincent

    • Serge93's avatar
      Serge93
      Icon for Occasional Contributor rankOccasional Contributor
      3 months ago

      Hello Wincent,

      Thank you for your answer but I meant the detail mapping as the following picture for Tdata :

      Do you have the same for the _tuser_hdr[255:0] signals ?

      Thank you.
      Serge

      • Wincent_Altera's avatar
        Wincent_Altera
        Icon for Regular Contributor rankRegular Contributor
        3 months ago

        Hi ,

        Thanks for your clarification, let me have sometime to check it.
        Get back to you later.

        Regards,
        Wincent_Altera