When you use the Hand Edit option, you are in charge of editing and maintaining the XDC files. While you will probably use the Tcl Console to verify the syntax of some constraints, you must discard the changes made in memory when closing or reloading your design.
In case of a conflict when saving the constraints, you are prompted to choose one of the following:
- Discarding the changes made in memory
- Saving the changes in a new file
- Overwriting the XDC files
Constraints creation is iterative. You can use IDE editors in some cases, and hand edit the constraint files in others.
Within each iteration described in the previous figure, do not use both options at the same time.
If you switch between the two options, you must first save your constraints or reload your design, to ensure that the constraints in memory are properly synchronized with the XDC files.