You must have a design in memory to validate constraints during editing. When you edit a constraint in the IDE, Vivado issues the equivalent XDC command in the Tcl Console to apply it in memory. You must apply an edited timing constraint in memory before saving it to the XDC file.
Before running synthesis or implementation, save the constraints in memory back to an XDC file in the project. The IDE prompts you to save constraints when 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 warns that this can cause synthesis and implementation to go
out of date. Select Remember Preference in the
dialog box to disable this warning.
When you save constraints, Vivado, the following happens:
- Saves all new constraints to the XDC file marked target in the constraints set for the design.
- Saves all edited constraints back to the XDC file from which they originated.
Note: The constraints management system
preserves the original XDC file format as much as possible.