The Device Constraints window (shown in the following figure) enables you to create, edit, and view internal VREF and DCI_CASCADE constraints. At the top of the Device Constraints window, you can select Internal VREF or DCI Cascade from the drop-down menu, as shown in the following figure. For more information, see this link in the Vivado Design Suite User Guide: I/O and Clock Planning (UG899). To open the Device Constraints window, select .
Figure 1. Device Constraints Window