After the Memory IP is configured, you must generate output products for use in implementation and third-party tools. When you generate output products, the Vivado tools create an IP-level XDC constraints file in the IP directory. The XDC file contains I/O physical constraints, such as IOSTANDARD, OUTPUT_IMPEDANCE, DRIVE, and SLEW. The Vivado tools derive these constraints from the configuration settings in the IP to aid in I/O planning. The constraints appear in the I/O Planning view layout.
For more information on generating output products, see this link in the Vivado Design Suite User Guide: Designing with IP (UG896).