The IOSTANDARD attribute is available to choose the values for an I/O standard for all I/O buffers. The supported I/O standards are listed in the specific UltraScale device data sheet [Ref 2]; however, Table: VCCO and VREF Requirements for Each Supported I/O Standard lists the IOSTANDARD support by I/O bank type (HR, HP, or both). The IOSTANDARD attribute uses the following syntax in the XDC file:
set_property IOSTANDARD value [get_ports port_name]