The UltraScale+ Devices Integrated Block for PCI Express solution requires the specification of timing and other physical implementation constraints to meet specified performance requirements for PCI Express® . These constraints are provided with the Endpoint and Root Port solutions in a Xilinx Design Constraints (XDC) file. Pinouts and hierarchy names in the generated XDC correspond to the provided example design.
To achieve consistent implementation results, an XDC containing these original, unmodified constraints must be used when a design is run through the AMD tools. For additional details on the definition and use of an XDC or specific constraints, see Vivado Design Suite User Guide: Using Constraints (UG903).
Constraints provided with the integrated block solution is tested in hardware and provide consistent results. Constraints can be modified, but modifications should only be made with a thorough understanding of the effect of each constraint. Additionally, support is not provided for designs that deviate from the provided constraints.