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cjak's avatar
cjak
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1 month ago
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Duplicate_hierarchy_depth / duplicate_register

According to timing recommendations I am trying to manually duplicate logic using either

set_instance_assignment -name duplicate_hierarchy_depth  reg level

or

set_instance_assignment -name duplicate_register reg level

according to AN-1016 section 4.2.4.2.

But, Quartus Prime 25.1 Lite complains that duplicate_hierarchy_depth is an illegal assignment. duplicate_register seems to be ignored by Quartus and I cannot find either of them in the Assignment Editor.

Any suggestions to what I am doing wrong?

  • RichardT_altera's avatar
    RichardT_altera
    1 month ago

    sstrell got it right—thank you for the clarification.

    The DUPLICATE_HIERARCHY_DEPTH assignment is supported only in Quartus Prime Pro, and AN‑1016 is written specifically for the Pro software flow. (Assignment Name in Pro: Duplicate One or More Registers in a Chain Based on Hierarchy)

    In Quartus Prime Standard/Lite, use the Manual Logic Duplication in the Assignment Editor to duplicate the register. A green check mark indicates that the assignment is valid.

    Regards,
    Richard Tan

14 Replies

  • sstrell's avatar
    sstrell
    Icon for Super Contributor rankSuper Contributor
    1 month ago

    I'm pretty sure duplicate_hierarchy_depth is only available in Pro, not Lite or Standard.

    As for duplicate_register, is your format of the assignment matching the AN (with -to <# of regs per fanout>)?

    • RichardT_altera's avatar
      RichardT_altera
      Icon for Super Contributor rankSuper Contributor
      1 month ago

      sstrell got it right—thank you for the clarification.

      The DUPLICATE_HIERARCHY_DEPTH assignment is supported only in Quartus Prime Pro, and AN‑1016 is written specifically for the Pro software flow. (Assignment Name in Pro: Duplicate One or More Registers in a Chain Based on Hierarchy)

      In Quartus Prime Standard/Lite, use the Manual Logic Duplication in the Assignment Editor to duplicate the register. A green check mark indicates that the assignment is valid.

      Regards,
      Richard Tan

  • cjak's avatar
    cjak
    Icon for Occasional Contributor rankOccasional Contributor
    1 month ago

    Great, thanks for the quick response! 

    Is there an application note similar to AN1016, for the Standard/Lite version of Quartus?

  • cjak's avatar
    cjak
    Icon for Occasional Contributor rankOccasional Contributor
    1 month ago

    I still have issues with a register-to-register timing, and I get the same recommendations from the Timing Analyzer 

    According to recommendations I try this assignment using the assignment editor 

    But, this does not make any difference on the timing report. Is it possible to verify that the assignment is actually considered? 

    Have I misunderstood how to set the assignment?

    • sstrell's avatar
      sstrell
      Icon for Super Contributor rankSuper Contributor
      1 month ago

      In the value column, you have to enter the number of duplications (an integer) of the source register set in the To column.  I'm surprised Quartus isn't giving you an error with that assignment the way you currently have it.
      Blank out the From column, set the To column to the register you want to duplicate, and then set a value in the Value column.

  • cjak's avatar
    cjak
    Icon for Occasional Contributor rankOccasional Contributor
    1 month ago

    This seems strange. Do you mean like this?

    As you can see, the description of the value-field is quite different from what you suggest...

  • RichardT_altera's avatar
    RichardT_altera
    Icon for Super Contributor rankSuper Contributor
    1 month ago

    Yes, it should looks something like this. 
    Filled in the respectively source node and the destination node. 

    I think there is a typo in the description, the value field is to specify the *number* of the duplicates needed to alleviate the fan-out load on a register.

    Regards,
    Richard Tan

  • cjak's avatar
    cjak
    Icon for Occasional Contributor rankOccasional Contributor
    1 month ago

    And the value = number of duplications?....not "name of duplicate node" as described in the text-field...

  • cjak's avatar
    cjak
    Icon for Occasional Contributor rankOccasional Contributor
    1 month ago

    After updating in the assignment editor, I get this message during compilation 

    The question is then, what does this really mean?

    ...and...

    This is how it looks in the code

    To my understanding, there is a path between interrupt_rx_mask_regs_s1.reg1 and o_gpio(7).

  • cjak's avatar
    cjak
    Icon for Occasional Contributor rankOccasional Contributor
    1 month ago

    Seems like I am able to add the correct assignments in the editor 

    Both are "green". I do not get any warnings during compilation, but the timing analyzer still recommends duplication of the node marked in blue, above.

    Has the assignment really been considered?

    • RichardT_altera's avatar
      RichardT_altera
      Icon for Super Contributor rankSuper Contributor
      1 month ago

      Could you share your design (Project > Archive Project) so I can further investigate the register duplication issue?
      If the design contains confidential information, you may send it to me via private message or share it through an FTP (File Transfer Portal).
       
      Regards,
      Richard Tan

       

       

      • cjak's avatar
        cjak
        Icon for Occasional Contributor rankOccasional Contributor
        1 month ago

        Hi,

        I'm sorry, but I cannot share the design. I've got a tip though, about restructuring my state-machine, which is relevant in this case. So, I will do that and come back if it still is a problem.