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Yamada1's avatar
Yamada1
Icon for Occasional Contributor rankOccasional Contributor
2 years ago
Solved

About loading constraints

It would be helpful if you could teach me about reading the constraints of the fitter. There is no particular problem when editing the SDC with Timing Analyzer, but when compiling afterwards, a warn...
Timing
  • RichardT_altera's avatar
    RichardT_altera
    2 years ago

    The constraints you used will remove the Unconstrained path being reported out because the -to node (RLO_CLK_node) that is false path is the same.

    At the end, designers need to know their design requirement and know where & when to use set_false_path. These constraints tell Timing Analyzer not to analyze specific paths or clock transfers. Once a path has been cut by either of these commands, there is no way to un-cut it, i.e. these constraints have the highest priority.

    Regards,

    Richard Tan

RichardT_altera's avatar
RichardT_altera
Icon for Super Contributor rankSuper Contributor
2 years ago

The constraints you used will remove the Unconstrained path being reported out because the -to node (RLO_CLK_node) that is false path is the same.

At the end, designers need to know their design requirement and know where & when to use set_false_path. These constraints tell Timing Analyzer not to analyze specific paths or clock transfers. Once a path has been cut by either of these commands, there is no way to un-cut it, i.e. these constraints have the highest priority.

Regards,

Richard Tan

  • Yamada1's avatar
    Yamada1
    Icon for Occasional Contributor rankOccasional Contributor
    2 years ago

    Thank you for answering.

    I understand that if the -to nodes are the same, the previous description and when using wildcards will have the same behavior.

    In addition, there was a question about the purpose in the comment received at 1:02 AM on 3/18, but the purpose of setting a false path is to "exclude it from being analyzed by the timing analyzer."

    Thank you very much for your detailed explanation of the details.