Hi, Tom and Kiran, You are probably right, although I have seen both interpretations out there. I like Scott's solution, too. One problem with [Model Selector] might be in having some of the pin pairs be differential and others single-ended in the same simulation (such as simulating for crosstalk effects). Best regards, Lynne -----Original Message----- From: owner-ibis@eda.org [mailto:owner-ibis@eda.org] On Behalf Of Tom Dagostino Sent: Thursday, April 06, 2006 10:09 AM To: Lynne D. Green; seshadri.kirankumar@wipro.com; ibis@eda.org; ibis-users@eda.org Subject: [IBIS] RE: [IBIS-Users] How to include Differential and Normal IO's of same pins Lynne I think you are missing the point. The two pins used for a differential pair in one case are able to be driven by single ended buffers in a non-differential mode at other times. The best solution to this that I can think of is to use a model selector to toggle between the differential buffer and the SE buffer. But when in the SE mode, comment out the [Diff pin] section for those 2 pins. Tom Dagostino Teraspeed(R) Labs 13610 SW Harness Lane Beaverton, OR 97008 503-430-1065 tom@teraspeed.com www.teraspeed.com Teraspeed Consulting Group LLC 121 North River Drive Narragansett, RI 02882 401-284-1827 -----Original Message----- From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org]On Behalf Of Lynne D. Green Sent: Thursday, April 06, 2006 10:01 AM To: seshadri.kirankumar@wipro.com; ibis@eda.org; ibis-users@eda.org Subject: RE: [IBIS-Users] How to include Differential and Normal IO's of same pins Hello, Kiran Kumar, Here is an example using the same IBIS buffer for both differential and non-differential buffers. If the buffer is fully symmetric (same edge rate, edge delay, etc.), then one can (should) use the same model for both sides of the diff I/O. This also removes the need to set two model selectors for one diff pair. Also, since tdelay_typ defaults to 0nsec, I would recommend setting it explicitly to that value. [Pin] signal_name model_name R_pin L_pin C_pin | Pin1 CLKP io1 Pin2 CLKN io1 Pin3 Single io1 | [Diff_pin] inv_pin vdiff tdelay_typ tdelay_min tdelay_max | Pin1 Pin2 200mV 0.0n NA NA | Best regards, Lynne "IBIS training when you need it, where you need it." Dr. Lynne Green Green Streak Programs 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 seshadri.kirankumar@wipro.com Sent: Thursday, April 06, 2006 6:10 AM To: ibis@eda.org; ibis-users@eda.org Subject: [IBIS-Users] How to include Differential and Normal IO's of same pins Hi Experts, I have a doubt regarding IBIS model of incorporating Differential and Non-differential Buffers in the same IBIS file As an Example there are 2 pins and corresponding LVDS definition is as follows [Pin] signal_name model_name R_pin L_pin C_pin | Pin1 CLKP LVDS_1 Pin2 CLKN LVDS_2 | [Diff_pin] inv_pin vdiff tdelay_typ tdelay_min tdelay_max | Pin1 Pin2 200mV NA NA NA For the same 2 above pins there exist normal(Non differential) IO's too, my doubt is that will it be possible to include both Differential and Normal IO's with any IBIS mechanism like how a {Model Selector] chooses different models for the same pin? If so please let me know on how? Suppose same if I do using [Model Selector] then what will be the impact of [Diff_pin] section on this pins when I am using only Normal models, this prototype is as listed below [Pin] signal_name model_name R_pin L_pin C_pin | Pin1 CLKP MODEL_1 Pin2 CLKN MODEL_2 | [Diff_pin] inv_pin vdiff tdelay_typ tdelay_min tdelay_max | Pin1 Pin2 200mV NA NA NA | [Model Selector] MODEL_1 LVDS_1 lvds model BUFFER_1 normal output buffer | [Model Selector] MODEL_2 LVDS_2 lvds model BUFFER_2 normal output buffer | What my opinion is option 2 is not proper as there is still valid(uncommented) [Diff_pin] section exist for the same pins while using normal IO's mode, please correct me if my concept is wrong Any Help on this is appreciable Thanks & Best Regards Kiran Kumar The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. 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