The ODT settings used in the simulations are controlled by a combination of the selections in the ODT Models page and ODT Behavior page in the DDRx Wizard. See the first part of this video to see some explanation of how they work together.
And see the section of this video starting at 7:00
The ODT setting for the DM signal is usually the same as for the memory DQ signals. You should run some interactive and model sweep simulations to determine the best ODT values for the different signals.