With this option, you edit and maintain the XDC files yourself. You can use the Tcl Console to verify the syntax of some constraints, but discard changes in memory when closing or reloading the design.
If a conflict occurs when saving constraints, you are prompted to do the following:
- Discard changes made in memory.
- Save changes in a new file.
- Overwrite the XDC files.
Constraint creation is iterative. You can use IDE editors in some cases and hand edit files in others.
Within each iteration described in Figure 1, do not use both options at the same time. If you switch between options, first save the constraints or reload the design. This ensures the constraints in memory stay synchronized with the XDC files.