Subject: Re: [IBIS-Users] ODT(On-Die-Termination) modeling ?
From: Peter LaFlamme (plaflamm@amcc.com)
Date: Thu Jan 23 2003 - 09:00:10 PST
Hi Jongho,
The real question/s is which simulators actually support this IBIS feature. The only way I have ever seen this feature implementable (in an IBIS model) is using the dynamic clamp submodel. I have asked about this before but there are apparently very few
people that know exactly how to implement it, or are willing to share their knowledge. I have never seen the procedure actually documented, so I can assume it has been implemented in many ways, some of which do not properly model the resistor termination
(my experience).
There are other ways using IBIS syntax, these are also not well documented, so you need an IBIS syntax expert to lead you through them. Additionally, I have tried these on 2 commonly used software programs and found that the syntax is ignored.
It would be a great service to the ibis community if someone who actually knows how to do this would document the procedure for publication on the IBIS webpage. It is my opinion that the ibis committee needs to focus on providing model creators with
standard ways of implementing all of the new features that they concieve. This will most likely improve the quality of models. This may already be something on the ibis agenda.
I am not looking to pick apart the IBIS committee or specs, or fingerpoint. I know they all do good work. I just hope that, other than accuracy, they should look at feature implementation, and that software companies let users of their tools know what IBIS
features are actually useable with their tools. I think we would all benefit.
Peter
> Jongho Kang wrote:
>
> DDR2 Dram has on-die-termination resistor.
> The ODT feature is designed to improve signal integrity
> of the memory channel by allowing the DRAM controller
> to independently turn on/off termination resistance for
> any or all DRAM device.
> Turning on/off termination resistance changes I/O buffer's
> I/V characteristics & rising/falling waveform.
> Does IBIS support ODT function?
> If not, how can I make I/O buffer IBIS including ODT function?
> Any comment will be appreciated.
>
> Thanks.
>
> ====================================
> Jongho Kang
> E-mail : jongho.kang@hynix.com
> Office : 82-31-639-1675/1971
> Mobile : 82-18-221-7806
> Product Application Engineering,
> Memory R&D, Hynix Semiconductor Inc.
> ====================================
-- Peter LaFlammeApplied Micro Circuits Corp. System Applications Engineer 200 Minuteman Rd, 3rd Floor Andover, MA 01810
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