The UltraScale+™ Devices Integrated Block for 100G Ethernet IP core solution requires the specification of timing and other physical implementation constraints to meet the specified performance requirements. These constraints are provided in a Xilinx® Design Constraints (XDC) file. Pinouts and hierarchy names in the generated XDC correspond to the provided example design of the 100G Ethernet IP core.
To achieve consistent implementation results, an XDC containing these original, unmodified constraints must be used when a design is run through the Xilinx tools. For additional details on the definition and use of an XDC or specific constraints, see the Vivado Design Suite User Guide: Using Constraints (UG903) [Ref 12] .
Constraints provided in the 100G Ethernet IP core have been verified through implementation and provide consistent results. Constraints can be modified, but modifications should only be made with a thorough understanding of the effect of each constraint.