Arpad, I can give you an even simpler answer, ever since the existence of IBIS, it can't model a simple problem like SSO. If you are a customer, would you choose a method that may be error if it is done wrong but at least give you a chance to predict the problem if it is done right, or, something just can't do the analysis AT ALL ? There are many road accidents with cars, but that doesn't mean you have to walk to work. Let me repeat the question I've asked many many times, how many of the member of the Si-list who are NOT just professional standards attendee or EDA tool vendors and have real responsibility to design system are actually using a standard IBIS model to analyze SSO today ? I rest my case. Garbage in garbage out, no matter it is SPICE or IBIS. At the end, whoever give the model out has the ultimate responsibility. But ever since the existence of IBIS, it can't address the problem high performance design (SSO and receiver performance to name a few). You and I know that behavioral models can address those problems long time ago but look at how long since the first known successful attempt (if you disagree with me on that reference, ping me off-line) until the standard committee even catch up with the idea. Seven years is a very long time, people can earn sabbatical out of that. Am I supposed to wait for another sabbatical if I want to model my equalizing receivers ? I've got problems on things I need to ship tomorrow. Let's take a closer look at AMS Here are the claims : a) It abstract your I/O to protect your IP Well, Gary's reference seems to suggest every I/O design is as simple as a university paper so may be your company have no problem handing out the I/O state machine design. Is that true ? On the same reference we are led to believe a SPICE level=1'ish model is really a behavioral model, ok I dig it, but do you think your company lawyers and design managers will buy that and freely handing it out without encryption ? Like I said before, it's like asking "Can you tell me the secret of your company ?" Ans : "I can't tell you in English, but I can tell you in Martians (just not to offend my earthly friends :-D)" Is that really possible (besides the fact that there is no Martian)? b) It is accurate and fast I still haven't seen any mention of SSO or how AMS can handle power impact on the I/O, may be SSO is no longer an important issue for GB serial ports ? How does one handle such modulation by predriver and substrate feedback from multiple power sources (core power for predriver, I/O power for main driver) without resorting to those level=1'ish transistor model ? A marketing paper like what Gary present can carefully craft the example to the advantage of the simulator but in reality how many interconnect is one simple S-parameter deck ? I would bet the real customer topology will more like a mix bag of circuit elements different vendor provide such as chip package, transmission line, terminators, discrets, connector models. How the speed of AMS will do when it is overloaded with a lot more circuit elements like R,L,C, transmission lines and S-parameters by different components ? Let's focus more on this little problem like a receiver, if you have to use the output of the receiver to predict a equalization how would you use your behavioral models to predict that ? Just take a look at those typical crazy FSB ringback, over-drive specs. Try a few case of real over drive and ring back cases which depends on common, differential mode, operating point, over drive, hysteretic etc and try construct a multi-dimensional equation/table to describe it and let's see how fast you will get. Ask the friends we both know and have already make pitches in this thread what do they think ? I am a fair person, show me a real life case and data and I will be convinced. c) It is standard and everyone support it I still couldn't figure out whether AMS is VHDL-AMS or Verilog-AMS, which one we are talk about here ? Can you tell me ? Does everyone use the same encryption to protect your IP ? If every tool has a different encryption, what kind of ZBB do you think you will get for ten different kinds of encryptors from ten different vendors ? -----Original Message----- From: Muranyi, Arpad [mailto:arpad.muranyi@xxxxxxxxx] Sent: Wednesday, March 23, 2005 11:54 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: package SSN model accuracy requirements Chris, The same is also true for SPICE! You are putting your faith into those engineer's hands who write your process files. And the average circuit designer usually has no clue for how to correct a bad transistor process file. Many times they don't even know where the limitations of the model are that they are using... Having worked for the same company I work for, you should remember some of the horror stories from those good old days when the IV curve of certain transistor models were on the order of 2-3x away from measurements... And what did we do to get a quick fix? We tweaked the .OPTIONS and did tricks with other simulation parameters because the process files were not going to change any time soon. (Good luck doing this independently for the N and P transistors). But I think I may have already said too much, so I will stop right here. Arpad =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] = On Behalf Of Chris Cheng Sent: Wednesday, March 16, 2005 3:31 PM Cc: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: package SSN model accuracy requirements ... =20 d) Which brings back my fundamental problem with behavioral modelling. I really don't know what the answers in c) should be but none of them = seems straight forward enough to me that the Joe app engineer can crank out in = the very near future. Anytime you have to attempt to deviate from the = original design flow of the Si houses (which I presume is dominated by SPICE), = you are putting faith in the app engineers who, up to now, can not even = abstract out a standard to help me predict a simple SSO problem other than using encrypted HSPICE. =20 What do you think ? ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: http://www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: http://www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: http://www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: http://www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu