When I attempt to change a pin location using Constraints Editor in my CoolRunner design, I am unable to do so. How do I make this adjustment?
You can resolve this issue as follows:
1. Open the Constraints Editor. The original pin-outs you entered should be visible.
2. Click on the "UCF Constraints (Read-Write)" tab at the bottom.
3. Left-click on the pin-out constraint you want to change, and delete it.
4. Repeat this step for all pin-outs that you want to change.
5. Close the Constraints Editor. Select "Yes" when asked if you want to save the file.
6. You are then asked to "Reset" your implementation. Click "Reset".
7. Re-open the Constraints Editor. The original pin-outs are gone, and you can enter the desired new pin locations via the PACE tool or a text editor.