Hi Tim, I’m glad that my email helped explain some things. Unfortunately I cannot help with your second question because it appears to be a problem with the specific simulator that you are using. I recommend that you contact your simulator’s customer support directly – they should be able to help you out. And while talking to them, be sure to ask about the difference between ideal ground and GND… You need to know. Good luck! Sam _____ From: Ibis Model [mailto:ibis_model@yahoo.com] Sent: Sunday, October 14, 2007 9:26 AM To: samchitwood@sigrity.com; Server EDA Subject: RE: [IBIS-Users] Package Modeling in IBIS -Matrix format Hi Sam Thank you for your reply. It gave me a clearer picture now. I have another concern on a previous question that I had posted, which is regarding calling a .pkg file, by adding in the [Define Package Model] section into the original IBIS file to be called by the simulator. Below is the question that I posted before, I hope you or someone else have an answer to it. Thanks. I am facing some of the problem regarding the package file. I have downloaded an IBIS file together with the package model file (in .pkg format). I have a problem in adding my desired .pkg file into my current IBIS file when I perform my simulation. Below is the situation: I have an IBIS file with below [Component] section. Now I would like to add in a package file with the extension .pkg (which I also place in the same folder with the IBIS file) [Component] abc [Manufacturer] studio.Inc. [Package] |variable typ min max R_pkg 161.54m 5.44m 459.46m L_pkg 2.40nH 0.43nH 5.35nH C_pkg 1.48pF 0.75pF 2.84pF | [Pin] signal_name model_name R_pin L_pin C_pin 1 HSTL HSTL 2 SSTL SSTL However, I read somewhere in the IBIS Spec and I had tried calling the .pkg file by placing in the same folder as my IBIS file but to no avail. I have some errors as such: 1. I added in the [Package Model] keyword and define the package model name as QS-SMT-cer-8-pin-pkgs 2. Then I copied the .pkg file content and paste it under the [Component] section - [Define Package Model]. But I have errors doing this as the pin numbers in the .pkg files are different from the pin number in my original IBIS file ([Pin] name goes 1, 2, 3 ... ) I follow the guideline of defining the package model but I could not find a way of calling the .pkg file from my original IBIS file when I perform my simulation. How do I used an IBIS file and include the package model which is in another separate .pkg file when I perform my simulation? Which is the best way to avoid having errors in the IBIS file so that I can load my IC modeling in the simulator tools (with errors in the IBIS file, im not able to proceed) Will the original Lumped RLC value interfere the result after I added in the .pkg package model? Appreciate if someone can answer my question above with the correct step of calling a separate .pkg package file with my IBIS file in the simulator tool. Thanks. Timmy Sam Chitwood <samchitwood@sigrity.com> wrote: Hi Tim, Sorry for my late reply. I just now had a chance to look at the file you provided. Every IBIS package model has a unique combination of benefits and limitations. Lynne mentioned one of the drawbacks, which is unfortunately common to many of the IBIS package models. Because of this assumption, an IBIS model should only have one logical “pin” for power and one for ground. Multiple RLCs for a single net are dangerous. The major benefit of this model is that coupling can be defined between pwr/sig/gnd. Because of this feature, the coupled RLC matrix format is the best official IBIS package model format for PCB designers wanting to perform system-level SSO analysis. (I emphasize official because many package designers commonly use other types of package models.) However, the model has to be correctly generated and implemented in simulation. Note the attached picture; it shows one of the dangers about many IBIS models. The trouble is in the “ground” pin. See how it can have a capacitance term? That’s bad. You may or may not know what the PCB simulator will do with that term. The picture shows how some tools use an “ideal ground” reference node that is different from the GND node shown in the picture. Does your simulator connect “ideal ground” and GND? You need to know this if you want to use models that contain C terms for ground nets (like the model you attached to your original email). This is also dangerous. Thankfully, there are other ways to generate the model that do not require the use of “ideal ground”. I prefer those techniques much better because then you do not have to worry as much about what the simulator does with “ideal ground” and GND. In summary, be suspicious of IBIS models that have either of the following: 1) Multiple pin RLCs for a single net [Pin] signal_name model_name R_pin L_pin C_pin 1 VDD POWER 1.1 1.3 1.5 2 VDD POWER 1.2 1.4 1.6 2) RLC entries for ¡°ground¡± nets 3 VSS GND 1.7 1.8 1.9 Either of these can cause incorrect results in some tools. Thanks, Sam _____ From: owner-ibis-users@server.eda.org [mailto:owner-ibis-users@server.eda.org] On Behalf Of Lynne D. Green Sent: Monday, October 01, 2007 9:42 AM To: 'Ibis Model'; 'Server EDA' Subject: RE: [IBIS-Users] Package Modeling in IBIS -Matrix format Hello, Tim, The IBIS specification has a chapter on the PKG format. The major limitation with PKG format is that it only supports pin-to-pad (no branching). Best regards, Lynne "IBIS training when you need it, where you need it." Dr. Lynne Green Green Streak Programs http://www.greenstreakprograms.com <http://www.greenstreakprograms.com/> 425-788-0412 lgreen22@mindspring.com _____ From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org] On Behalf Of Ibis Model Sent: Monday, October 01, 2007 2:54 AM To: Server EDA Subject: [IBIS-Users] Package Modeling in IBIS -Matrix format Hi, I have come across this IBIS model with the respective package model file (in .pkg format) and it seem to me that the package information for all RLC is presented in a matrix format. Is there any available document that can explain how this numbers can be useful to the user as well as how they play a role in the simulation? Else, can IBIS open forum helps to explain how these values are being presented and how can the simulation tools use these information to verify whether the simulator already included the package model. I will be glad if you can point me to any document related to this matrix RLC package modeling. Appreciate your reply on this. Please find attachement the package model file. Regards Tim _____ Take the Internet to Go: Yahoo!Go puts the <http://us.rd.yahoo.com/evt=48253/*http:/mobile.yahoo.com/go?refer=1GNXIC> Internet in your pocket: mail, news, photos & more. -- This message has been scanned for viruses and dangerous content by <http://www.mailscanner.info/> MailScanner, and is believed to be clean. -- This message has been scanned for viruses and dangerous content by <http://www.mailscanner.info/> MailScanner, and is believed to be clean. -- This message has been scanned for viruses and dangerous content by <http://www.mailscanner.info/> MailScanner, and is believed to be clean. _____ Pinpoint <http://us.rd.yahoo.com/evt=48250/*http:/searchmarketing.yahoo.com/arp/spons oredsearch_v9.php?o=US2226&cmp=Yahoo&ctv=AprNI&s=Y&s2=EM&b=50> customers who are looking for what you sell. -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. -------------------------------------------------------------------- |For help or to subscribe/unsubscribe, e-mail majordomo@eda-stds.org |with the appropriate command message(s) in the body: | | help | subscribe ibis <optional e-mail address, if different> | subscribe ibis-users <optional e-mail address, if different> | unsubscribe ibis <optional e-mail address, if different> | unsubscribe ibis-users <optional e-mail address, if different> | |or e-mail a request to ibis-request@eda-stds.org. | |IBIS reflector archives exist under: | | http://www.eda-stds.org/pub/ibis/email_archive/ Recent | http://www.eda-stds.org/pub/ibis/users_archive/ Recent | http://www.eda-stds.org/pub/ibis/email/ E-mail since 1993Received on Mon Oct 15 08:44:30 2007
This archive was generated by hypermail 2.1.8 : Mon Oct 15 2007 - 08:45:28 PDT