5. Use the Design Bar to compile the design.

6. Select the top-level view in the Design Hierarchy Browser. Select the Design Analysis taskbar and click on the Report Missing Constraints icon.

7. The missing constraint report is displayed in the text editor. One input pin (data_en) is reported as unconstrained. Highlight "data_en". Using the right mouse button (RMB), select "Trace to Hierarchy" from the popup menu to cross reference the pin in the Schematic Viewer.