The ODT attribute uses the following syntax in the XDC file:
set_property ODT RTT_48 [get_ports port_name]
to create a Thevenin equivalent to the circuit shown in This Figure
Uncalibrated split ODT is supported on all voltage-referenced I/O standards. Table: HD I/O Supported Standards defines the specific standards that are supported to use with this feature. The user-programmable input termination setting is implemented with a 96W pull-up and 96W pull-down to provide the equivalent 48W to VCCO/2 termination.