Constraints Editing within the Wizard - 2023.2 English

Vivado Design Suite User Guide: Using Constraints (UG903)

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2023.2 English

Each step of the wizard can recommend several constraints. Depending on the constraint, take one of the following actions:

  • Uncheck the constraints you do not want to create, using one of the following methods:
    • Remove each constraint from the list, one at a time, by unchecking each line.
    • Remove all constraints by unchecking the upper left check box of the table.
    Tip: Alternatively, you can right-click the constraint, and select Do Not Create Constraint, as shown in the following figure.
    Figure 1. Skipping Recommended Constraints Using the Context Menu

    In the following figure, clk1 and ddr_clk_in are unchecked and will be skipped.

    Figure 2. Creating and Skipping Recommended Constraints

  • Enter the missing values by clicking on the cells that show undefined (for example, the Frequency or Period value for clk2 and clk3 in the previous figure).

    You can edit several constraints at the same time by selecting the corresponding rows and clicking the Edit Selected Rows button, as shown in the following figure.

    Figure 3. Editing Several Recommended Constraints

    Next, fill out any required fields, such as Frequency and Period as shown in the following figure:

    Figure 4. Entering Parameters for Several Recommended Constraints

    Editing multiple constraints at a time is particularly helpful for input and output delay constraints.

  • Simply review the constraints if no action is required.

When all the checked recommended constraints have been reviewed and completed, click Next to proceed to the next page. Any entries that you missed prevent the wizard from moving to the next step.

Use the Back button to revisit a page. If you edit any constraint on a previous page and click Next, the wizard re-analyzes the design and recommends new constraints accordingly. In most cases, the previously recommended constraints not affected by the change are reinstated. If you only view a previous page without modifying any of its recommended constraints, the wizard does not re-run any analysis, which usually saves runtime.

Important: You cannot use the Timing Constraints wizard to edit existing timing constraints. Instead, you must use the Timing Constraints window.