You must have a design in memory to validate your constraints during editing. When you edit a constraint using the Vivado IDE user interface, the equivalent XDC command is issued in the Tcl Console in order to apply it in memory. An edited timing constraint must be applied in memory before it can be saved to the XDC file.
Before you can run synthesis or implementation, you must save the constraints in memory back to an XDC file that belongs to the project. The Vivado IDE prompts you to save your constraints whenever necessary.
Do one of the following to save your constraints manually:
- Click Save Constraints.
- Select .
Note: When you save the in-memory constraints, a dialog box opens to remind you that this could cause the synthesis and implementation to go out of date. Select the Remember Preference check box on this dialog box to disable future instances of this warning.
When you run these commands, Vivado does the following:
- Saves all new constraints to the XDC file marked target in the constraints set associated with your design.
- Saves all edited constraints back to the XDC file from which they originated.
Note: The constraints management system preserves the original XDC files format as much as possible.