Date: Mon Jun 24 2013 - 07:31:47 PDT
Girija, He means that the driver must not be pulling the net high or low. If the driver is a standard CMOS push-pull driver, that means both the NFET and the PFET devices must be off. In other words, the driver is in a high-impedance state. If either the NFET or PFET devices are on, the driver output impedance will be in the range of 50 Ohms (or slightly higher/lower). The EDA simulator will probably not allow this unless the Model_type is set to 3-state. Greg Edlund Senior Engineer Signal Integrity and System Timing IBM Systems & Technology Group 3605 Hwy. 52 N Bldg 050-3 Rochester, MN 55901 From: Girija V Chougala <gvch@cypress.com> To: Gregory R Edlund/Rochester/IBM@IBMUS Cc: "ibis-users@eda.org" <ibis-users@eda.org>, "owner-ibis-users@eda.org" <owner-ibis-users@eda.org> Date: 06/24/2013 09:18 AM Subject: RE: [IBIS-Users] IBIS query Sent by: owner-ibis-users@eda.org Greg, IBIS model is already done. This is the question from the customer. I am not able to understand what he means telling that he needs to simulate data lines in which ibis model need to be tri stated. Regards, Girija From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org] On Behalf Of Gregory R Edlund Sent: Monday, June 24, 2013 6:34 PM To: Girija V Chougala Cc: ibis-users@eda.org; owner-ibis-users@eda.org Subject: Re: [IBIS-Users] IBIS query Girija, IBIS uses the following syntax to identify a tri-state model: Model_type 3-state Are you making a new IBIS model or using one that's already made? The IBIS community has free tools available for making IBIS models. If you are new to IBIS, I recommend reading the original IBIS 1.1 specification and the Cookbook. http://www.eda.org/ibis/ver1.1/ver1_1.ibs http://www.eda.org/ibis/tools/ Greg Edlund Senior Engineer Signal Integrity and System Timing IBM Systems & Technology Group 3605 Hwy. 52 N Bldg 050-3 Rochester, MN 55901 Inactive hide details for Girija V Chougala ---06/24/2013 02:11:00 AM---Hi, Please guide me in the following query which I got Girija V Chougala ---06/24/2013 02:11:00 AM---Hi, Please guide me in the following query which I got from one of my customer, From: Girija V Chougala <gvch@cypress.com> To: "ibis-users@eda.org" <ibis-users@eda.org> Date: 06/24/2013 02:11 AM Subject: [IBIS-Users] IBIS query Sent by: owner-ibis-users@eda.org Hi, Please guide me in the following query which I got from one of my customer, Question: How i can assign a tri state model? I need to simulate a local bus data line in which ibis model is a member which need to be tri stated. Please let me know what need to be done and what is he asking. I appreciate quick response. Regards, Girija This message and any attachments may contain Cypress (or its subsidiaries) confidential information. If it has been received in error, please advise the sender and immediately delete this message. -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. This message and any attachments may contain Cypress (or its subsidiaries) confidential information. If it has been received in error, please advise the sender and immediately delete this message. -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. -- 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 mikelabonte@eda-stds.org |or ibis-request@eda-stds.org | |IBIS reflector archives exist under: | | http://www.eda-stds.org/ibis/email_archive/ Recent | http://www.eda-stds.org/ibis/users_archive/ Recent | http://www.eda-stds.org/ibis/email/ E-mail since 1993
