The IBUF_LOW_PWR attribute allows an optional trade-off between performance and power. This attribute is set to TRUE by default, which implements the input buffer in the lower-power rather than the higher-performance mode.
The change in power between high-performance and low-power mode can be estimated using the Xilinx Power Estimator (XPE) spreadsheet tool (download at www.amd.com/power).
The IBUF_LOW_PWR attribute is applied to the I/O buffer instance and uses the following syntax in the XDC file:
set_property IBUF_LOW_PWR TRUE|FALSE [get_ports port_name
]
See the UltraScale Architecture Libraries Guide (UG974) for information on accessing this attribute in UNISIM instantiation.