jeff.bailey

DDR3 wizard - ODT IBIS Model Selectors tab - ODT settings for controller tied together?

Discussion created by jeff.bailey on Jan 27, 2012
Latest reply on Jan 30, 2012 by weston_beal

When trying to change an ODT setting for my DDR3 controller, if I make a setting change under any one of the "DQS, DQS#", "DQ", or "DM" columns, it enforces that mode selection on all three columns for the controller.  This is causing me some issues in teh setup.  The DM "ODT Enabled" mode is not a valid mode as DM is unidirectional driven by teh controller, yet I need to set a valid ODT mode for the DQS, DQS#, and DQ nets.

 

If I set a valid ODT mode for DQS, DQ#, and DQ nets, the change is enforced on the DM nets as well, and for some reason I get an error about all of my address nets being assigned that model at the controller as well, this is especially odd because they are not even ODT nets, and a driver model for all of those nets is assigned correctly in the "Non-ODT IBIS Model Selectors" tab.

 

There just seems to be a whole lot not adding up here, is there maybe some problem with how the models I'm using are grouping nets?  I can run interactive simulations on all of this stuff outside of the wizard just fine, using the same models.

 

 

Thanks in advance for any insight, I'll check back Monday.

 

Jeff

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