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ymiler's avatar
ymiler
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1 year ago
Solved

Locate all FF in the OBUF

Hi

What is the constraint to locate all the FF in the OBUF ?

I need a minimum and constant routing latency for each synthesis

  • Seems like you're using Pro version. Then probably can use GPIO IP under section I/O in IP Catalog. The register mode choose DDIO.


6 Replies

  • sstrell's avatar
    sstrell
    Icon for Super Contributor rankSuper Contributor

    Fast Output Register assignment in the Assignment Editor.

  • ShengN_altera's avatar
    ShengN_altera
    Icon for Super Contributor rankSuper Contributor

    Hi,


    May I know do you have any further concern or consideration?


    Thanks,

    Regards,

    Sheng


    • ymiler's avatar
      ymiler
      Icon for Contributor rankContributor

      Thank you for the reply

      I have 1 more question (relevant to the previous question),

      I need to create a source synchronous connection between two FPGAs.

      FPGA A needs to transmit 32 data bits along with a clock signal to FPGA B. All 32 bits are sampled by a PLL clock ( FPGA A )

      and then sent to 32 IO_OBUF pins.

      The same PLL clock, which samples the 32 data bits, is also connected to another IO_OBUF.

      I would like to align the latency between the clock and the 32 data bits.

      Is there an IP core or alternative method to create an ODDR that is sampled by the PLL clock and generates a new clock that is aligned with the flip-flop for the 32 data bits?

    • ymiler's avatar
      ymiler
      Icon for Contributor rankContributor

      DDIO ?

      There is no IP name like it in the IP catalog

  • ShengN_altera's avatar
    ShengN_altera
    Icon for Super Contributor rankSuper Contributor

    Seems like you're using Pro version. Then probably can use GPIO IP under section I/O in IP Catalog. The register mode choose DDIO.