Scott- Good question, indeed. A couple of thoughts:First of all, while defining a standard way to support PVT may be a good start, there are a number of other ways in which we all need to come to a common understanding of what should go into a good IBIS AMI model. We might tackle these subjects one at a time, but I would expect that the net result is that we would be talking for a long time before we produced a comprehensive result.
Secondly, I submit that, as an industry, we have less experience with algorithmic modeling now than we did with electrical modeling at the time IBIS was first created. Thus, it wouldn't hurt for us to get a bit more collective experience with algorithmic modeling before we attempt further standardization. We have what we need to move forward for the time being, and we're all going to learn a lot over the coming year.
I suggest that once we've gained more experience, the next step would be to have some presentations or white papers on what constitutes a good IBIS AMI model. Such material would be immediately useful to both system developers and model developers, and would position us to take the next step in standardization.
Mike S. Scott McMorrow wrote:
MikeHuang's question is quite informative. For many years now, IBIS models have been required to carry PVT information in a standardized and well-documented way. With IBIS AMI there is no standard for including or documenting PVT variation.An interesting question is: should there be a standard way to include and/or document PVT variation and controls?Scott Scott McMorrow Teraspeed Consulting Group LLC 121 North River Drive Narragansett, RI 02882 (401) 284-1827 Business (401) 284-1840 Fax http://www.teraspeed.com Teraspeed® is the registered service mark of Teraspeed Consulting Group LLC Mike Steinberger wrote:Huang-The short version to Walter's answer is that the IBIS AMI model maker must incorporate the effects of Process/Temperature/Voltage (PVT) into their model and then expose PVT as one or more input parameters to the model. For example, SiSoft has delivered models that had PVT as an explicit input parameter.This is one of a number of areas in which the IBIS AMI specification makes it possible to write a good model, but does not define what a good model is, much less force model makers to write good models. In effect, we chose to depend on system developers such as yourself to let us know what you need to see in a model in order to consider it to be acceptable. What you've in effect said is that you expect a proper model to include the effects of PVT, and that's a perfectly reasonable expectation that any competent model maker should be able to satisfy.I can offer a statement of what I believe constitutes a high quality IBIS AMI model package, and I will if you wish. What's really important, however, is for system developers to explicitly state their expectations. (Golden Rule of Business: He who has the gold makes the rules.)Hope this helps. Mike S. Walter Katz wrote:Huang,IBIS-AMI models are controlled by parameters that have various solution space capabilities. These solution space capabilities are used to control the configuration of the Tx/Rx model (e.g. Tap coefficients, and peaking filter selection). The solution space of a parameter is controlled by its “Format”. “Format” can be:* A single Value * A Range * A range with a specific number of Steps * A range with a specific Increment * A List of values * A Table * A Gaussian distribution * A Dual-Dirac distribution * A DjRj distribution * A CornerThe “Corner” format specifies a <typ value>, <slow value> and <fast value>. These values are intended to be used in conjunction with the corresponding <typ>, <min> and <max> values of the analog part of the IBIS model.This is described in page three of BIRD 104.1 Regards, Walter Walter Katz Signal Integrity Software, Inc. (303) 449-2308 -----Original Message-----*From:* ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]*On Behalf Of *Huang chunxing*Sent:* Tuesday, June 24, 2008 2:06 AM *To:* IBIS-ATM *Cc:* guantao@xxxxxxxxxx *Subject:* [ibis-macro] IBIS-AMI Hi AMI experts, Does IBIS-AMI support modeling Serdes with different cases, like, typical case, Best case and worst case. This question may look some idiotic. But I hope some experts here may give me a definite answer and how to arrange these models in IBIS according to AMI specification. Thanks! Regards, Huang HUAWEI TECHNOLOGIES CO.,LTD. huawei_logo Address: Huawei Industrial Base Bantian Longgang Shenzhen 518129, P.R.China Tel: +86 755 89651163 Fax: +86 755 89652294 E-mail: huangchunxing@xxxxxxxxxx <mailto:huangchunxing@xxxxxxxxxx> www.huawei.com <http://www.huawei.com>------------------------------------------------------------------------------------------------------------------------------------- This e-mail and its attachments contain confidential information from HUAWEI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender byphone or email immediately and delete it!--------------------------------------------------------------------- IBIS Macro website : http://www.eda.org/pub/ibis/macromodel_wip/ IBIS Macro reflector: //www.freelists.org/list/ibis-macro To unsubscribe send an email: To: ibis-macro-request@xxxxxxxxxxxxx Subject: unsubscribe--------------------------------------------------------------------- IBIS Macro website : http://www.eda.org/pub/ibis/macromodel_wip/ IBIS Macro reflector: //www.freelists.org/list/ibis-macro To unsubscribe send an email: To: ibis-macro-request@xxxxxxxxxxxxx Subject: unsubscribe
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