The "Regenerate Core" process does not use the current project settings when I regenerate a core. This causes the implementation tools to fail or to give less than optimal placement results.
A Virtex core with RLOCs is used in a Virtex-II design. The Virtex "RxCy.Sn RLOCs" constraints are generated differently in Virtex-II, which causes a placement error.
You must use the Generate Core "Under Current Project Settings" option to generate cores for current project settings.
You can set this option in the Generate Core Process Properties window in Project Navigator, or by running Generate Core -> "Under Current Project Settings" option from the main CORE Generator GUI.
To change the Generate Core Process Properties window in Project Navigator, right-click the Generate Core Process, select "Properties...", and then change the property value.
To open the main CORE Generator GUI from Project Navigator and generate a new core with the current project settings, follow these steps:
1. Select a core (<filename>.xco) in the "Sources in Project" window.
2. In the "Processes for Current Source" window, expand the CORE Generator toolbox to display the "Manage Cores" process.
3. Double-click the "Manage Cores" process, and the CORE Generator main GUI will launch.
4. Verify that the family displayed by the "Target Family" heading is the correct family.
5. In the "Generated Modules" window, select all cores that you wish to regenerate.
6. Right-click and select Regenerate -> Under current project settings.
7. After all cores are regenerated, exit CORE Generator, and return to Project Navigator.