[SI-LIST] Will ODT on DDR2 work?

Jory, Ludvik,
 
Remember that ODT only works when the I/O is in the "I" state.  I do not
recommend saving 30 cents of resistors for the trouble-shooting headache you
will create.  Refer to JESD79-2C for more information on how DDR2 works.
 
 
Date: Mon, 5 Feb 2007 18:14:57 -0800 (PST)
From: Jory McKinley <jory_mckinley@xxxxxxxxx>

Subject: [SI-LIST] Re: Will ODT on DDR2 work?

Hello Ludvik,

In my experience it always a good idea to simulate this transfer but we have
found that using Full ODT drivers on the Micron side tend to create some
undesirable Signal Integrity issues at the Controller (in your case the
Virtex-V). In most cases a Half strength ODT driver will work however you
will need to simulate this while checking for overshot and ringback at the
Virtex-V. Also make sure that you have adequate crosstalk rules in place.

-Jory

Jeffrey Johnson, C.I.D.

Module R&D Engineer

NanYa Technologies - Texas LLC

Tel: (713) 774-4113 Ext. 135

FAX:  (713) 774-3819

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