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From: owner-ibis-users@ (ibis-users) To: ibis-users-digest@eda.org Subject: ibis-users V1 #5 Reply-To: Sender: owner-ibis-users@ Errors-To: owner-ibis-users@ Precedence: bulk ibis-users Wednesday, May 1 2002 Volume 01 : Number 005 ---------------------------------------------------------------------- Date: Wed, 20 Mar 2002 01:36:29 -0800 From: SanJose1.TOSHIBA_TAEC@taec.toshiba.com Subject: [IBIS-Users] Report to Recipient(s) Incident Information:- Originator: owner-ibis-users@eda.org Recipients: ibis-users@vhdl.org Subject: [IBIS-Users] Happy nice Lady Day WARNING: The file You can find technical info in this folder.pif you received was infected with the W32/Klez.gen@MM virus. The file attachment was not successfully cleaned. |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 20 Mar 2002 02:04:10 -0800 From: System Attendant Subject: [IBIS-Users] ScanMail Message: To Recipient virus found and action taken. This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. - ------_=_NextPart_001_01C1CFF6.94CCAAB0 Content-Type: text/plain ScanMail for Microsoft Exchange has detected virus-infected attachment(s). Sender = QA_Engr4 Recipient(s) = ibis-users@server.vhdl.org Subject = [IBIS-Users] Happy nice Lady Day Scanning Time = 03/20/2002 02:04:10 Action on virus found: The attachment You can find technical info in this folder.pif matched file blocking settings. ScanMail has Moved it. The attachment was moved to C:\Program Files\Trend\Smex\Alert\You can find technical info in this folder3c985e9ad7.pif_. Warning to recipient. ScanMail has detected a virus. Attachment with the virus was quarantined. - ------_=_NextPart_001_01C1CFF6.94CCAAB0 Content-Type: text/html Content-Transfer-Encoding: quoted-printable ScanMail Message: To Recipient virus found and action = taken.

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- ------_=_NextPart_001_01C1CFF6.94CCAAB0-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Sat, 23 Mar 2002 14:26:59 -0800 (PST) From: whiz kid Subject: [IBIS-Users] IBIS Question. Hi folks, I have some dumb questions. 1) How can I identify the value of the pullup resistor being modeled by looking at the Pullup and the Powerclamp values. 2) Why do we need to use different fixture voltages when specifing the Rising and Falling waveforms. Any help is greatly appreciated. Thanks, Rahul. __________________________________________________ Do You Yahoo!? Yahoo! Movies - coverage of the 74th Academy Awards® http://movies.yahoo.com/ |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Sun, 24 Mar 2002 17:30:57 -0500 From: John Angulo Subject: [IBIS-Users] List posting now closed to non-members Hello, Due to the recent surge in spam and virus related emails, posting to the IBIS lists is now restricted to list members. This has already stopped some inappropriate mail to the lists. Be aware that the following posts to the IBIS lists on 3/20/02 contained a virus: From: "nutwooduk" To: Subject: [IBIS] Have a excite Lady Day Date: Wednesday, March 20, 2002 1:46 AM From: "QA_Engr4" To: Subject: [IBIS-Users] Happy nice Lady Day Date: Wednesday, March 20, 2002 1:46 AM The other unwanted traffic on 3/20 consisted of automated warnings about this threat from the service providers of several list members. Under the new restricted posting policy, if you send email to the list, remember to use the exact address with which you subscribed. Otherwise, the list administration software will not allow the post. It will forward the email to me as a non-member attempt to post. In this event, I will send the email to the list myself and notify you of the problem. Domain reorganizations within a company frequently lead to unexpected changes in email addresses, so I will be monitoring this issue carefully. In the future, if a list member becomes infected with a virus, and either of the IBIS lists ever becomes overwhelmed by the resulting traffic, we will temporarily moderate all postings until the problem is resolved. These policies should keep the lists clean. Thanks for your patience with yesterday's flurry of unwanted email. Please respond to me directly with any feedback. John Angulo IBIS Open Forum Postmaster |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Mon, 25 Mar 2002 12:54:59 -0500 From: Jon Powell Subject: RE: [IBIS-Users] IBIS Question. You should NOT be using different fixture voltages for RISING and FALLING in most model cases. You should be using 2 voltages and making two rising and two falling waveforms. For standard 5 volts CMOS you use: 50 ohms to 5 volts and 50 ohms to 0 volts it is actually very important to the simulation math that you have the same voltages in both sets of waveforms. have fun Jon Powell > -----Original Message----- > From: whiz kid [mailto:we_r_frendz@yahoo.com] > Sent: Saturday, March 23, 2002 2:27 PM > To: ibis-users@eda.org > Subject: [IBIS-Users] IBIS Question. > > > Hi folks, > I have some dumb questions. > 1) How can I identify the value of the pullup resistor > being modeled by looking at the Pullup and the > Powerclamp values. > 2) Why do we need to use different fixture voltages > when specifing the Rising and Falling waveforms. > > Any help is greatly appreciated. > > Thanks, > Rahul. > > __________________________________________________ > Do You Yahoo!? > Yahoo! Movies - coverage of the 74th Academy Awards® > http://movies.yahoo.com/ > |------------------------------------------------------------------ > |For help or to subscribe/unsubscribe, email majordomo@eda.org > |with just the appropriate command message(s) in the body: > | > | help > | subscribe ibis > | subscribe ibis-users > | unsubscribe ibis > | unsubscribe ibis-users > | > |or email a written request to ibis-request@eda.org. > | > |IBIS reflector archives exist under: > | > | http://www.eda.org/pub/ibis/email_archive/ Recent > | http://www.eda.org/pub/ibis/users_archive/ Recent > | http://www.eda.org/pub/ibis/email/ E-mail since 1993 > |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Mon, 25 Mar 2002 14:46:56 -0600 From: Gang Huo Subject: [IBIS-Users] IBIS and HSPICE simulation result question Hi All, When I try to correlate a IBIS I/O model simulation with HSPICE model using HSPICE version 2000.4, the result is pretty good on the standard load and open transmission line load. One thing concerns me is that in the simulation of a load of transmission line to receiver simulation, the overshoot level of the signal is much higher when using the IBIS model than the HSPICE model, (the difference between two case is 0.5V nominal and 0.7V in best case, this is a 3.3v I/O buffer). I doubt this may be because of the clamp tables in the IBIS model. But as the creator of the model, I am pretty confident that the clamp tables in the IBIS model are correct, so can someone give me an idea what else in the IBIS model may cause this? Will this cause a problem to the users? And is there any good way to address this issue when creating the models? Thanks in advance, Gang Huo |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 26 Mar 2002 11:34:02 -0800 From: "Jeremy Plunkett" Subject: RE: [IBIS-Users] IBIS and HSPICE simulation result question Gang, the IBIS model clamps will only affect the level of overshoot when the model you created is the receiver. If you are driving the model output into a transmission line test load, the level of overshoot at the end of the line will depend on the edge rate and output impedance of your IBIS model, but not on the clamps. I do a correlation check into a test load that matches the termination conditions that the driver will see in use, and correlate the waveform at _the driver's own output pad_ before looking at anything else. If the driver will be used on a terminated bus like DDR or GTL, use a test load that is a resistor equal to the transmission line impedance, connected to the termination voltage level. If the driver will be driving from the middle of a terminated bus, divide the transmission line impedance by two since the driver actually drives 2 transmission lines in parallel. If the driver will be used on unterminated lines, than the load should be a pullup or pulldown resistor equal to the nominal trace impedance. If your extraction was accurate, you should see near-perfect correlation of the output waveform into these loads. In particular, if you do a correlation into the same loads that are used for the IBIS model VT curves (usually 50 ohms pullup and pulldown), and you don't see 99% perfect correlation, then there is definitely a problem with either the model or your simulation setup. Good luck, hope this helped! Jeremy |>--/\/\/--((((((((()--|> Jeremy Plunkett Signal Integrity Engineer ServerWorks Corp www.serverworks.com |>--/\/\/--((((((((()--|> - -----Original Message----- From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org]On Behalf Of Gang Huo Sent: Monday, March 25, 2002 12:47 PM To: ibis-users@eda.org Subject: [IBIS-Users] IBIS and HSPICE simulation result question Hi All, When I try to correlate a IBIS I/O model simulation with HSPICE model using HSPICE version 2000.4, the result is pretty good on the standard load and open transmission line load. One thing concerns me is that in the simulation of a load of transmission line to receiver simulation, the overshoot level of the signal is much higher when using the IBIS model than the HSPICE model, (the difference between two case is 0.5V nominal and 0.7V in best case, this is a 3.3v I/O buffer). I doubt this may be because of the clamp tables in the IBIS model. But as the creator of the model, I am pretty confident that the clamp tables in the IBIS model are correct, so can someone give me an idea what else in the IBIS model may cause this? Will this cause a problem to the users? And is there any good way to address this issue when creating the models? Thanks in advance, Gang Huo |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 26 Mar 2002 14:11:10 -0600 From: Gang Huo Subject: Re: [IBIS-Users] IBIS and HSPICE simulation result question Hi, All Thank Jeremy for your response. I should clear myself, the simulation with problem is a driver drive a transmission then to the same I/O cell as the receiver. The simulation shows good correlation when driving a open transmission line or a 50 Ohm load. Well, I got a 'extreme currents present in GND clamp curve' warning when running ibischk3 (around 30A). I know this is highly likely due to the 'perfect' diode with no intrinsic resistance in the HSPICE model per IBIS cookbook. And the IBIS model may not correlate with the real buffer performance, but I am surprised it did not correlate well with the HSPICE model simulation in this case, since the IBIS model is derived from the same HSPICE model I used. Without further information on the diode information, is there a good way to solve the problem? Will adding a small resistor with a fixed value (say 5-7 Ohm) do the trick? Thanks in advance. Huo,Gang Jeremy Plunkett wrote: > Gang, > the IBIS model clamps will only affect the level of overshoot when the model > you created is the receiver. If you are driving the model output into a > transmission line test load, the level of overshoot at the end of the line > will depend on the edge rate and output impedance of your IBIS model, but > not on the clamps. > > I do a correlation check into a test load that matches the termination > conditions that the driver will see in use, and correlate the waveform at > _the driver's own output pad_ before looking at anything else. If the > driver will be used on a terminated bus like DDR or GTL, use a test load > that is a resistor equal to the transmission line impedance, connected to > the termination voltage level. If the driver will be driving from the > middle of a terminated bus, divide the transmission line impedance by two > since the driver actually drives 2 transmission lines in parallel. If the > driver will be used on unterminated lines, than the load should be a pullup > or pulldown resistor equal to the nominal trace impedance. > > If your extraction was accurate, you should see near-perfect correlation of > the output waveform into these loads. In particular, if you do a > correlation into the same loads that are used for the IBIS model VT curves > (usually 50 ohms pullup and pulldown), and you don't see 99% perfect > correlation, then there is definitely a problem with either the model or > your simulation setup. > > Good luck, hope this helped! > > Jeremy > > |>--/\/\/--((((((((()--|> > > Jeremy Plunkett > Signal Integrity Engineer > ServerWorks Corp > www.serverworks.com > > |>--/\/\/--((((((((()--|> > > -----Original Message----- > From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org]On Behalf Of > Gang Huo > Sent: Monday, March 25, 2002 12:47 PM > To: ibis-users@eda.org > Subject: [IBIS-Users] IBIS and HSPICE simulation result question > > Hi All, > > When I try to correlate a IBIS I/O model simulation with HSPICE model > using HSPICE version 2000.4, the result is pretty good on the standard > load and open transmission line load. One thing concerns me is that in > the simulation of a load of transmission line to receiver simulation, > the overshoot level of the signal is much higher when using the IBIS > model than the HSPICE model, (the difference between two case is 0.5V > nominal and 0.7V in best case, this is a 3.3v I/O buffer). > > I doubt this may be because of the clamp tables in the IBIS model. But > as the creator of the model, I am pretty confident that the clamp tables > in the IBIS model are correct, so can someone give me an idea what else > in the IBIS model may cause this? Will this cause a problem to the > users? And is there any good way to address this issue when creating the > models? > > Thanks in advance, > Gang Huo > > |------------------------------------------------------------------ > |For help or to subscribe/unsubscribe, email majordomo@eda.org > |with just the appropriate command message(s) in the body: > | > | help > | subscribe ibis > | subscribe ibis-users > | unsubscribe ibis > | unsubscribe ibis-users > | > |or email a written request to ibis-request@eda.org. > | > |IBIS reflector archives exist under: > | > | http://www.eda.org/pub/ibis/email_archive/ Recent > | http://www.eda.org/pub/ibis/users_archive/ Recent > | http://www.eda.org/pub/ibis/email/ E-mail since 1993 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 26 Mar 2002 13:49:59 -0800 From: "Jeremy Plunkett" Subject: RE: [IBIS-Users] IBIS and HSPICE simulation result question hi, not sure if I should address you by Huo or Gang...let me know? sorry for the misunderstanding, if your model is both the source and reciever then your input clamps are the determining factor. I am surprised that the IBIS model would should higher over/undershoot than the spice model; typically if there is any error it is double-counting the clamp current(clamps end up 2x as strong as the spice deck), not undercounting it. When you are testing the model, do you have the hspice B element set up with power=on or power=off? It might be worth your while to try both settings and compare the results. Also, make sure that you have all necessary and optional nodes and voltages defined for the model type you are using. Don't leave out the supply connections for the power clamp and ground clamp, not all hspice versions include them as a default, no matter what the manual may say. Also, check that the buffer capacitance is the same between the ibis model and spice deck at the process and temperature you are using. Capacitance can vary significantly between process corners and even as the pad voltage varies from one supply rail to the other and especially beyond the rails; the IBIS format is not flexible enough to represent this at the present time. If the capacitance of the spice model in the conditions at the pad when the overshoot occurs is significantly higher than the capacitance specified in the IBIS model, then you will see higher overshoot in the IBIS model even though the diode IV curves were extracted correctly. Regarding the diode resistance, if you have the physical part in hand or even just similar parts made in the same process, you can measure the diode clamp resistance(for one case of process, and at room temperature) fairly easily. Just connect the part to it's standard supplies (but preferably not to any other valuable circuitry), and connect a variable voltage pulse source to a tristated signal pin. Set the pulse source to drive the signal pad beyond the rail with a duty cycle of not more than 10%, and measure the current flowing into the part by measuring the voltage at the pin with an oscilloscope. The pulse source has a 50ohm output, so the voltage you measure at the pin will not be the voltage that you set up on the front panel. Measure the peak of that voltage (it should be a square/rectangular waveform), and calculate the clamp current as Ic=(2xVf-VL)/50 where Ic=clamp current, Vf=pulse voltage set at the front panel, and VL=peak voltage measured at the pin. Measure the clamp current for pin voltages of 1v and 2v past the rail, then calculate the clamp resistance as Rc=1/(I1-I2), where I1 and I2 are the respective current readings. regards, Jeremy |>--/\/\/--((((((((()--|> Jeremy Plunkett Signal Integrity Engineer ServerWorks Corp www.serverworks.com |>--/\/\/--((((((((()--|> - -----Original Message----- From: ghuo@lsil.com [mailto:ghuo@lsil.com] Sent: Tuesday, March 26, 2002 12:11 PM To: Jeremy Plunkett Cc: ibis-users@eda.org Subject: Re: [IBIS-Users] IBIS and HSPICE simulation result question Hi, All Thank Jeremy for your response. I should clear myself, the simulation with problem is a driver drive a transmission then to the same I/O cell as the receiver. The simulation shows good correlation when driving a open transmission line or a 50 Ohm load. Well, I got a 'extreme currents present in GND clamp curve' warning when running ibischk3 (around 30A). I know this is highly likely due to the 'perfect' diode with no intrinsic resistance in the HSPICE model per IBIS cookbook. And the IBIS model may not correlate with the real buffer performance, but I am surprised it did not correlate well with the HSPICE model simulation in this case, since the IBIS model is derived from the same HSPICE model I used. Without further information on the diode information, is there a good way to solve the problem? Will adding a small resistor with a fixed value (say 5-7 Ohm) do the trick? Thanks in advance. Huo,Gang Jeremy Plunkett wrote: > Gang, > the IBIS model clamps will only affect the level of overshoot when the model > you created is the receiver. If you are driving the model output into a > transmission line test load, the level of overshoot at the end of the line > will depend on the edge rate and output impedance of your IBIS model, but > not on the clamps. > > I do a correlation check into a test load that matches the termination > conditions that the driver will see in use, and correlate the waveform at > _the driver's own output pad_ before looking at anything else. If the > driver will be used on a terminated bus like DDR or GTL, use a test load > that is a resistor equal to the transmission line impedance, connected to > the termination voltage level. If the driver will be driving from the > middle of a terminated bus, divide the transmission line impedance by two > since the driver actually drives 2 transmission lines in parallel. If the > driver will be used on unterminated lines, than the load should be a pullup > or pulldown resistor equal to the nominal trace impedance. > > If your extraction was accurate, you should see near-perfect correlation of > the output waveform into these loads. In particular, if you do a > correlation into the same loads that are used for the IBIS model VT curves > (usually 50 ohms pullup and pulldown), and you don't see 99% perfect > correlation, then there is definitely a problem with either the model or > your simulation setup. > > Good luck, hope this helped! > > Jeremy > > |>--/\/\/--((((((((()--|> > > Jeremy Plunkett > Signal Integrity Engineer > ServerWorks Corp > www.serverworks.com > > |>--/\/\/--((((((((()--|> > > -----Original Message----- > From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org]On Behalf Of > Gang Huo > Sent: Monday, March 25, 2002 12:47 PM > To: ibis-users@eda.org > Subject: [IBIS-Users] IBIS and HSPICE simulation result question > > Hi All, > > When I try to correlate a IBIS I/O model simulation with HSPICE model > using HSPICE version 2000.4, the result is pretty good on the standard > load and open transmission line load. One thing concerns me is that in > the simulation of a load of transmission line to receiver simulation, > the overshoot level of the signal is much higher when using the IBIS > model than the HSPICE model, (the difference between two case is 0.5V > nominal and 0.7V in best case, this is a 3.3v I/O buffer). > > I doubt this may be because of the clamp tables in the IBIS model. But > as the creator of the model, I am pretty confident that the clamp tables > in the IBIS model are correct, so can someone give me an idea what else > in the IBIS model may cause this? Will this cause a problem to the > users? And is there any good way to address this issue when creating the > models? > > Thanks in advance, > Gang Huo > > |------------------------------------------------------------------ > |For help or to subscribe/unsubscribe, email majordomo@eda.org > |with just the appropriate command message(s) in the body: > | > | help > | subscribe ibis > | subscribe ibis-users > | unsubscribe ibis > | unsubscribe ibis-users > | > |or email a written request to ibis-request@eda.org. > | > |IBIS reflector archives exist under: > | > | http://www.eda.org/pub/ibis/email_archive/ Recent > | http://www.eda.org/pub/ibis/users_archive/ Recent > | http://www.eda.org/pub/ibis/email/ E-mail since 1993 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 27 Mar 2002 10:57:40 -0500 From: "Timothy Coyle" Subject: [IBIS-Users] Positive Ground Clamp Curve This is a multipart message in MIME format. - --=_alternative 0058118085256B89_= Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit I am trying to gain ground clamp curve data for an input buffer. I do a DC sweep on the input pin and measure the current. However, I get positive current. I am using HSPICE. Is there a current convention thing going on in HSPICE or is something else wrong? Thanks in advance for any info. Tim - --=_alternative 0058118085256B89_= Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit
I am trying to gain ground clamp curve data for an input buffer. I do a DC sweep on the input pin and measure the current. However,
I get positive current. I am using HSPICE. Is there a current convention thing going on in HSPICE or is something else wrong?
Thanks in advance for any info.

Tim
- --=_alternative 0058118085256B89_=-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 27 Mar 2002 09:07:56 -0800 From: "Muranyi, Arpad" Subject: RE: [IBIS-Users] Positive Ground Clamp Curve This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. - ------_=_NextPart_001_01C1D5B1.F09D1A80 Content-Type: text/plain; charset="iso-8859-1" Tim, Yes, there is. I usually do it this way: Arpad ====================================================================== 3-state I-V plot generator ********************************************************************** * This is a I-V curve generator for input or 3-stated buffers. * It runs in transient mode and shows the I-V curve in the same * orientation as it is seen on a curve tracer. ********************************************************************** .OPTIONS POST=1 PROBE .PROBE TRAN Voltage=V(Sweep) Pulldown=I(Vsweep) .TRAN 0.1ms 198ms ********************************************************************** .param Vcc_DC=3.3 ********************************************************************** Vpow Vcc 0 DC=Vcc_DC Vsweep 0 Sweep PWL 0ns 3.3V 198ms -6.6V ********************************************************************** X1 0 Sweep Vcc 0 0 BUFFER_SUBCKT_NAME * input output power GND enable ********************************************************************** .END ********************************************************************** - -----Original Message----- From: Timothy Coyle [mailto:Timothy.Coyle@nsc.com] Sent: Wednesday, March 27, 2002 7:58 AM To: ibis-users@server.eda.org Subject: [IBIS-Users] Positive Ground Clamp Curve I am trying to gain ground clamp curve data for an input buffer. I do a DC sweep on the input pin and measure the current. However, I get positive current. I am using HSPICE. Is there a current convention thing going on in HSPICE or is something else wrong? Thanks in advance for any info. Tim - ------_=_NextPart_001_01C1D5B1.F09D1A80 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Tim,

Yes, there=20 is. I usually do it this way:

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=3D= =3D=3D=3D=3D=3D=3D=3D

3-state I-V=20 plot=20 generator
***********************************************************= ***********
*=20 This is a I-V curve generator for input or 3-stated buffers.
* It = runs in=20 transient mode and shows the I-V curve in the same
* orientation as = it is=20 seen on a curve=20 tracer.
*************************************************************= *********
.OPTIONS=20 POST=3D1 PROBE
.PROBE TRAN Voltage=3DV(Sweep) = Pulldown=3DI(Vsweep)
.TRAN 0.1ms=20 198ms
***************************************************************= *******
.param=20 Vcc_DC=3D3.3
********************************************************= **************
Vpow =20 Vcc 0 DC=3DVcc_DC
Vsweep 0 Sweep PWL 0ns 3.3V 198ms=20 - -6.6V
***************************************************************= *******
X1=20 0 Sweep = Vcc 0 =20 0 BUFFER_SUBCKT_NAME

* =20 input output power GND=20 enable
**************************************************************= ********
.END
****************************************************= ******************

-----Original Message-----
From: Timothy Coyle=20 [mailto:Timothy.Coyle@nsc.com]
Sent: Wednesday, March 27, = 2002 7:58=20 AM
To: ibis-users@server.eda.org
Subject: = [IBIS-Users]=20 Positive Ground Clamp Curve

I am trying to gain ground clamp curve data for an input = buffer. I=20 do a DC sweep on the input pin and measure the current. However, =
I get positive current. I am using = HSPICE.=20 Is there a current convention thing going on in HSPICE or is = something=20 else wrong?
Thanks in = advance for any=20 info.

Tim =
- ------_=_NextPart_001_01C1D5B1.F09D1A80-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 27 Mar 2002 15:41:03 -0800 From: "Sanchez, Louis" Subject: [IBIS-Users] Temperature Range: Hello.............. I have a question regarding the proper format to use for the IBIS model keyword:[Temperature Range]. According to version 3.2 of the EIA IBIS Standard, the format is: typ, min, and max. The example given on page 29 of the referenced standard is: typ: 27.0, min: -50, max: 130.0. Yet, I have seen IBIS models from various sources that specify the min temperature as high, in this case 130; and the max temperature as low, in this case -50. Can someone comment on what the proper entry should be? I tend to believe the standard, but I have seen so many IBIS files with the min and max entries reversed that I just had to ask. Thank You, Louis A. Sanchez |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 27 Mar 2002 16:02:56 -0800 From: "Mirmak, Michael" Subject: RE: [IBIS-Users] Temperature Range: Louis, The {Temperature Range] keyword values are ordered depending on conditions, not on numerical value (unlike C_comp). In other words, your "min" temperature value corresponds to the temperature used to get the "min" data, not the smallest numerical temperature in your range. Section 9 of the specification details Data Derivation methods and points out that, for CMOS processes, "min" corner usually corresponds to high temeratures, while the "max" corner corresponds to low temperatures. Bipolar technologies, on the other hand, typically show association between "min" corner and low temperature, etc. While not so noted, I believe the spec example refers to a bipolar buffer. I hope this helps! - - Michael Mirmak, Intel Corp. - -----Original Message----- From: Sanchez, Louis [mailto:louis.sanchez@intel.com] Sent: Wednesday, March 27, 2002 3:41 PM To: 'ibis-users@server.eda.org' Subject: [IBIS-Users] Temperature Range: Hello.............. I have a question regarding the proper format to use for the IBIS model keyword:[Temperature Range]. According to version 3.2 of the EIA IBIS Standard, the format is: typ, min, and max. The example given on page 29 of the referenced standard is: typ: 27.0, min: -50, max: 130.0. Yet, I have seen IBIS models from various sources that specify the min temperature as high, in this case 130; and the max temperature as low, in this case -50. Can someone comment on what the proper entry should be? I tend to believe the standard, but I have seen so many IBIS files with the min and max entries reversed that I just had to ask. Thank You, Louis A. Sanchez |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 27 Mar 2002 19:12:16 -0500 From: "Lynne Green" Subject: RE: [IBIS-Users] Temperature Range: Hello, Louis, This is described in the IBIS 3.2 spec: | The optional [Temperature Range] keyword will contain the temperature which | causes or amplifies the slow, weak conditions in the "min" column and the | temperature which causes or amplifies the fast, strong conditions in the | "max" column. Therefore, the "min" column for [Temperature Range] will | contain the lowest value for bipolar models (TTL and ECL) and the highest | value for CMOS models. You are probably seeing some CMOS models and some bipolar models. - - Lynne - -----Original Message----- From: Sanchez, Louis [mailto:louis.sanchez@intel.com] Sent: Wednesday, March 27, 2002 3:41 PM To: 'ibis-users@server.eda.org' Subject: [IBIS-Users] Temperature Range: Hello.............. I have a question regarding the proper format to use for the IBIS model keyword:[Temperature Range]. According to version 3.2 of the EIA IBIS Standard, the format is: typ, min, and max. The example given on page 29 of the referenced standard is: typ: 27.0, min: -50, max: 130.0. Yet, I have seen IBIS models from various sources that specify the min temperature as high, in this case 130; and the max temperature as low, in this case -50. Can someone comment on what the proper entry should be? I tend to believe the standard, but I have seen so many IBIS files with the min and max entries reversed that I just had to ask. Thank You, Louis A. Sanchez |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 27 Mar 2002 16:14:38 -0800 From: "Sanchez, Louis" Subject: RE: [IBIS-Users] Temperature Range: Hi.............. I want to thank all who responded. These inputs cleared up my confusion. Thanks, Lou A. Sanchez - -----Original Message----- From: Mirmak, Michael Sent: Wednesday, March 27, 2002 4:03 PM To: Sanchez, Louis; 'ibis-users@server.eda.org' Subject: RE: [IBIS-Users] Temperature Range: Louis, The {Temperature Range] keyword values are ordered depending on conditions, not on numerical value (unlike C_comp). In other words, your "min" temperature value corresponds to the temperature used to get the "min" data, not the smallest numerical temperature in your range. Section 9 of the specification details Data Derivation methods and points out that, for CMOS processes, "min" corner usually corresponds to high temeratures, while the "max" corner corresponds to low temperatures. Bipolar technologies, on the other hand, typically show association between "min" corner and low temperature, etc. While not so noted, I believe the spec example refers to a bipolar buffer. I hope this helps! - - Michael Mirmak, Intel Corp. - -----Original Message----- From: Sanchez, Louis [mailto:louis.sanchez@intel.com] Sent: Wednesday, March 27, 2002 3:41 PM To: 'ibis-users@server.eda.org' Subject: [IBIS-Users] Temperature Range: Hello.............. I have a question regarding the proper format to use for the IBIS model keyword:[Temperature Range]. According to version 3.2 of the EIA IBIS Standard, the format is: typ, min, and max. The example given on page 29 of the referenced standard is: typ: 27.0, min: -50, max: 130.0. Yet, I have seen IBIS models from various sources that specify the min temperature as high, in this case 130; and the max temperature as low, in this case -50. Can someone comment on what the proper entry should be? I tend to believe the standard, but I have seen so many IBIS files with the min and max entries reversed that I just had to ask. Thank You, Louis A. Sanchez |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 27 Mar 2002 16:27:54 -0800 From: "Bill Hargin" Subject: RE: [IBIS-Users] Temperature Range: Hi Louis: The spec and your initial example are correct. Mistakes in IBIS models are a dime a dozen, unfortunately. As a recent thread discussed, many models do not appear to be validated in simulators before they're released, and a lot of models have obvious syntactical errors. Best Regards, Bill Hargin Direct: 425-702-0744 Fax: 425-702-0305 Cognition Consulting Electronic Design Software and Consulting http://www.CognitionConsulting.com > -----Original Message----- > From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org]On > Behalf Of Sanchez, Louis > Sent: Wednesday, March 27, 2002 3:41 PM > To: 'ibis-users@server.eda.org' > Subject: [IBIS-Users] Temperature Range: > > > Hello.............. > > I have a question regarding the proper format to use for the IBIS model > keyword:[Temperature Range]. According to version 3.2 of the EIA IBIS > Standard, the format is: typ, min, and max. The example given on > page 29 of > the referenced standard is: typ: 27.0, min: -50, max: 130.0. Yet, I have > seen IBIS models from various sources that specify the min temperature as > high, in this case 130; and the max temperature as low, in this case -50. > Can someone comment on what the proper entry should be? I tend to believe > the standard, but I have seen so many IBIS files with the min and max > entries reversed that I just had to ask. > > Thank You, > Louis A. Sanchez > |------------------------------------------------------------------ > |For help or to subscribe/unsubscribe, email majordomo@eda.org > |with just the appropriate command message(s) in the body: > | > | help > | subscribe ibis > | subscribe ibis-users > | unsubscribe ibis > | unsubscribe ibis-users > | > |or email a written request to ibis-request@eda.org. > | > |IBIS reflector archives exist under: > | > | http://www.eda.org/pub/ibis/email_archive/ Recent > | http://www.eda.org/pub/ibis/users_archive/ Recent > | http://www.eda.org/pub/ibis/email/ E-mail since 1993 > |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 27 Mar 2002 16:43:07 -0800 From: "Peters, Stephen" Subject: RE: [IBIS-Users] Temperature Range: Hi Bill, Louis: Actually, IBIS models with a 'min' temperature higher than the 'max' temperature are perfectly correct, assuming the part being modeled is CMOS. As explained on pg. 57 of the IBIS spec, the 'min' value of [Temperature Range] is the value that causes or amplifies the slow/weak condition, while the 'max' value is the value that causes or amplifies the fastest/strongest condition. With CMOS, cold is fast & hot is slow. TTL logic is just the opposite. Hope this helps. Regards, Stephen Peters Intel Corp. - -----Original Message----- From: Bill Hargin [mailto:billh@cognitionconsulting.com] Sent: Wednesday, March 27, 2002 4:28 PM To: Sanchez, Louis; 'ibis-users@server.eda.org' Subject: RE: [IBIS-Users] Temperature Range: Hi Louis: The spec and your initial example are correct. Mistakes in IBIS models are a dime a dozen, unfortunately. As a recent thread discussed, many models do not appear to be validated in simulators before they're released, and a lot of models have obvious syntactical errors. Best Regards, Bill Hargin Direct: 425-702-0744 Fax: 425-702-0305 Cognition Consulting Electronic Design Software and Consulting http://www.CognitionConsulting.com > -----Original Message----- > From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org]On > Behalf Of Sanchez, Louis > Sent: Wednesday, March 27, 2002 3:41 PM > To: 'ibis-users@server.eda.org' > Subject: [IBIS-Users] Temperature Range: > > > Hello.............. > > I have a question regarding the proper format to use for the IBIS model > keyword:[Temperature Range]. According to version 3.2 of the EIA IBIS > Standard, the format is: typ, min, and max. The example given on > page 29 of > the referenced standard is: typ: 27.0, min: -50, max: 130.0. Yet, I have > seen IBIS models from various sources that specify the min temperature as > high, in this case 130; and the max temperature as low, in this case -50. > Can someone comment on what the proper entry should be? I tend to believe > the standard, but I have seen so many IBIS files with the min and max > entries reversed that I just had to ask. > > Thank You, > Louis A. Sanchez > |------------------------------------------------------------------ > |For help or to subscribe/unsubscribe, email majordomo@eda.org > |with just the appropriate command message(s) in the body: > | > | help > | subscribe ibis > | subscribe ibis-users > | unsubscribe ibis > | unsubscribe ibis-users > | > |or email a written request to ibis-request@eda.org. > | > |IBIS reflector archives exist under: > | > | http://www.eda.org/pub/ibis/email_archive/ Recent > | http://www.eda.org/pub/ibis/users_archive/ Recent > | http://www.eda.org/pub/ibis/email/ E-mail since 1993 > |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 27 Mar 2002 18:22:35 -0700 From: Al Davis Subject: Re: [IBIS-Users] Temperature Range: On Wednesday 27 March 2002 17:43, Peters, Stephen wrote: > Actually, IBIS models with a 'min' temperature higher than the > 'max' temperature are perfectly correct, assuming the part being > modeled is CMOS. As explained on pg. 57 of the IBIS spec, the 'min' > value of [Temperature Range] is the value that causes or amplifies > the slow/weak condition, while the 'max' value is the value that > causes or amplifies the fastest/strongest condition. With CMOS, > cold is fast & hot is slow. TTL logic is just the opposite. That doesn't make sense. The only place it is actually used in calculations in transit time, when [TTpower] or [TTgnd] keywords are used. These define the nonlinear capacitance in parallel with the clamps. High temperature is always low capacitance, therefore "fast". |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 27 Mar 2002 23:50:24 -0500 From: "Todd Westerhoff" Subject: RE: [IBIS-Users] Temperature Range: Mistakes in IBIS models are now a dime a dozen? When did the price go up? Todd ;-) Todd Westerhoff Signal Integrity Engineer Hammerhead Networks 5 Federal Street - Billerica, MA - 01821 email:twester@hhnetwk.com - ph: 978-671-5084 ============================================ "I’m starting With the man in the mirror I’m asking him to change his ways And no message could have been any clearer If you wanna make the world a better place Take a look at yourself, and then make a change" - - "Man in the Mirror", Michael Jackson - -----Original Message----- From: owner-ibis-users@server.eda.org [mailto:owner-ibis-users@server.eda.org]On Behalf Of Bill Hargin Sent: Wednesday, March 27, 2002 7:28 PM To: Sanchez, Louis; 'ibis-users@server.eda.org' Subject: RE: [IBIS-Users] Temperature Range: Hi Louis: The spec and your initial example are correct. Mistakes in IBIS models are a dime a dozen, unfortunately. As a recent thread discussed, many models do not appear to be validated in simulators before they're released, and a lot of models have obvious syntactical errors. Best Regards, Bill Hargin Direct: 425-702-0744 Fax: 425-702-0305 Cognition Consulting Electronic Design Software and Consulting http://www.CognitionConsulting.com > -----Original Message----- > From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org]On > Behalf Of Sanchez, Louis > Sent: Wednesday, March 27, 2002 3:41 PM > To: 'ibis-users@server.eda.org' > Subject: [IBIS-Users] Temperature Range: > > > Hello.............. > > I have a question regarding the proper format to use for the IBIS model > keyword:[Temperature Range]. According to version 3.2 of the EIA IBIS > Standard, the format is: typ, min, and max. The example given on > page 29 of > the referenced standard is: typ: 27.0, min: -50, max: 130.0. Yet, I have > seen IBIS models from various sources that specify the min temperature as > high, in this case 130; and the max temperature as low, in this case -50. > Can someone comment on what the proper entry should be? I tend to believe > the standard, but I have seen so many IBIS files with the min and max > entries reversed that I just had to ask. > > Thank You, > Louis A. Sanchez > |------------------------------------------------------------------ > |For help or to subscribe/unsubscribe, email majordomo@eda.org > |with just the appropriate command message(s) in the body: > | > | help > | subscribe ibis > | subscribe ibis-users > | unsubscribe ibis > | unsubscribe ibis-users > | > |or email a written request to ibis-request@eda.org. > | > |IBIS reflector archives exist under: > | > | http://www.eda.org/pub/ibis/email_archive/ Recent > | http://www.eda.org/pub/ibis/users_archive/ Recent > | http://www.eda.org/pub/ibis/email/ E-mail since 1993 > |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Thu, 28 Mar 2002 06:32:20 -0800 From: "Mellitz, Richard" Subject: RE: [IBIS-Users] Temperature Range: Al, Regarding the statement: "High temperature is always low capacitance, therefore "fast"." Is only true of buffers whose slew rate is controlled by capacitance. There are adaptive slew rate and driver strength schemes that can change the dependence of slew rate and buffer strength on temperature. Just some food for thought. :-) Rich Mellitz, Intel - -----Original Message----- From: Al Davis [mailto:aldavis@ieee.org] Sent: Wednesday, March 27, 2002 8:23 PM To: ibis-users@server.eda.org Subject: Re: [IBIS-Users] Temperature Range: On Wednesday 27 March 2002 17:43, Peters, Stephen wrote: > Actually, IBIS models with a 'min' temperature higher than the > 'max' temperature are perfectly correct, assuming the part being > modeled is CMOS. As explained on pg. 57 of the IBIS spec, the 'min' > value of [Temperature Range] is the value that causes or amplifies > the slow/weak condition, while the 'max' value is the value that > causes or amplifies the fastest/strongest condition. With CMOS, > cold is fast & hot is slow. TTL logic is just the opposite. That doesn't make sense. The only place it is actually used in calculations in transit time, when [TTpower] or [TTgnd] keywords are used. These define the nonlinear capacitance in parallel with the clamps. High temperature is always low capacitance, therefore "fast". |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Thu, 28 Mar 2002 13:04:50 -0500 From: "Ingraham, Andrew" Subject: RE: [IBIS-Users] Temperature Range: > That doesn't make sense. The only place it is actually used in > calculations in transit time, when [TTpower] or [TTgnd] keywords are > used. These define the nonlinear capacitance in parallel with the > clamps. High temperature is always low capacitance, therefore "fast". But high temperature also means higher channel resistance, therefore "slow". Whether or not an IBIS model actually makes use of the [Temperature Range] numbers themselves, is another matter, however. (Aside from the [TTpower] or [TTgnd] cases you mentioned.) There is plenty of data in an IBIS data sheet ("model") that may not be used by the simulator. Most implementation details are left as an exercise for the simulator vendor. It is conceivable, if not entirely practical, that a smart simulator might select the appropriate device strength/speed (or interpolate between them), based on the desired simulation temperature. Or a simulator might give the user a message that the pairing he has selected (CMOS max strength devices simulated at max temperature) is impractical, so results would be overly conservative compared to the models. Andy |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Thu, 28 Mar 2002 13:19:28 -0500 From: "Ingraham, Andrew" Subject: RE: [IBIS-Users] IBIS and HSPICE simulation result question Are you comparing waveforms observed at the same electrical point, i.e., package pin vs. die pad? If both were observed at the package pin, are you sure the IBIS model's package parameters are correct? If there's a wide range of values, can you tell that the simulator selects the value within that range that you did in your HSPICE simulation? What simulator did you use when checking the IBIS model? If Star-HSPICE, did you add a package model (since HSPICE's IBIS implementation doesn't include one)? If Star-HSPICE, did you include the "optional" nd_pc and nd_gc nodes? If you don't, HSPICE turns off the clamps whenever the driver is not enabled! If you over-drive the receiver by a few volts, with a moderate source resistance, does it clamp at all? Andy |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Thu, 28 Mar 2002 13:42:44 -0500 From: Mike LaBonte Subject: RE: [IBIS-Users] Temperature Range: At 01:04 PM 3/28/2002 -0500, Ingraham, Andrew wrote: >It is conceivable, if not entirely practical, that a smart simulator might >select the appropriate device strength/speed (or interpolate between >them), based on the desired simulation temperature. SPECCTRAQuest did at one time interpolate between I/V curves based on the design operating junction temperature of each part, as determined by thermal analysis. However, that was discontinued after doubts were raised about temperature being the primary factor. You would want to determine how much of the fast/slow variation is due to temperature before undertaking this. Mike LaBonte |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 2 Apr 2002 13:09:05 -0500 From: "Timothy Coyle" Subject: [IBIS-Users] Using Differential IBIS Buffers in HSPICE This is a multipart message in MIME format. - --=_alternative 006419C685256B8F_= Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hi, I am trying to use differential output IBIS buffers in HSPICE. I set up independent voltage sources on each of the inverting and non-inverting output buffer. I put 100 ohms across the outputs since it is LVDS. I'm getting some strange results. Both buffers have non-inverting polarity and the voltage swing is way off for LVDS. Any help would be appreciated. Thanks in advance, Tim - --=_alternative 006419C685256B8F_= Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit
Hi,
I am trying to use differential output IBIS buffers in HSPICE. I set up independent voltage sources on each of the inverting and non-inverting output buffer.
I put 100 ohms across the outputs since it is LVDS. I'm getting some strange results. Both buffers have non-inverting polarity and the voltage swing is way off
for LVDS. Any help would be appreciated.

Thanks in advance,
Tim
- --=_alternative 006419C685256B8F_=-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 2 Apr 2002 10:59:14 -0800 From: Kim Helliwell Subject: [IBIS-Users] IBIS Imponderables I'm sure I'm not the only person who has wondered about these: 1. Why is a mismatch in the file name an error, rather than a warning? In fact, why does it matter at all? 2. Why are only lowercase letters allowed in an IBIS file name? 3. Why are AC mismatches warnings rather than errors? 4. Why does s2ibis2 appear to generate IBIS models with AC mismatches in the first place? (Judging from the number of IBIS models I've seen that used s2ibis2 and had such problems, it is apparently the norm.) Feel free to provide answers or add your own imponderables. Kim Helliwell Apple Computer kimgh@apple.com 408 974 9936 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 2 Apr 2002 15:48:23 -0500 From: Matthew Flora Subject: RE: [IBIS-Users] IBIS Imponderables This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. - ------_=_NextPart_001_01C1DA87.BABAF7E0 Content-Type: text/plain; charset="iso-8859-1" Dear Kim, I'll stick my neck out ... > 1. Why is a mismatch in the file name an error, rather than > a warning? In fact, why does it matter at all? At this point, just backwards compatibility with IBIS 1.0? > 2. Why are only lowercase letters allowed in an IBIS file name? To make life easier for files accessed across multiple platforms. Some platforms are sensitive to the case of filenames, some are not. Name collisions can occur when filenames on a case sensitive platform differ only in case and those files are then transferred to or accessed from a case- insensitive platform. Requiring all of one case gets around the problem. > 3. Why are AC mismatches warnings rather than errors? I have been told by a couple model builders who build models from measurement of actual parts that they have two different rigs for doing DC and AC measurements. This is an example where the two measurements may not be in exact agreement. The latest parser does generate an error when the discrepancies become large. > 4. Why does s2ibis2 appear to generate IBIS models > with AC mismatches in the first place? (Judging > from the number of IBIS models I've seen that > used s2ibis2 and had such problems, it is > apparently the norm.) Sorry, I don't know. Best regards, Matthew Flora - ------_=_NextPart_001_01C1DA87.BABAF7E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable RE: [IBIS-Users] IBIS Imponderables

Dear Kim,

I'll stick my neck out ...

> 1. Why is a mismatch in the file name an error, = rather than
> a warning? In = fact, why does it matter at all?

At this point, just backwards compatibility with IBIS = 1.0?

> 2. Why are only lowercase letters allowed in an = IBIS file name?

To make life easier for files accessed across = multiple platforms. Some
platforms are sensitive to the case of filenames, = some are not. Name
collisions can occur when filenames on a case = sensitive platform differ only
in case and those files are then transferred to or = accessed from a case-
insensitive platform. Requiring all of one = case gets around the problem.

> 3. Why are AC mismatches warnings rather than = errors?

I have been told by a couple model builders who build = models from measurement
of actual parts that they have two different rigs = for doing DC and AC
measurements. This is an example where the two = measurements may not be in exact agreement. The latest parser = does generate an error when the discrepancies become large.

> 4. Why does s2ibis2 appear to generate IBIS = models
>      with AC = mismatches in the first place? (Judging
>      from the number = of IBIS models I've seen that
>      used s2ibis2 and = had such problems, it is
>      apparently the = norm.)

Sorry, I don't know.

Best regards,
Matthew Flora

- ------_=_NextPart_001_01C1DA87.BABAF7E0-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 2 Apr 2002 15:57:19 -0500 From: "Lynne Green" Subject: RE: [IBIS-Users] IBIS Imponderables Hi, Kim, 1) Ancient history that lingers with us. I personally wouldn't mind seeing this one reduced to a warning (or even eliminated) in IBIS 4. 2) This one is because some Windows Apps (such as copying a file to a CD!) thoughtfully change case on files. This rule makes life easier when files have to go to both UNIX and Windows. 3) Since there is no agreement on where to draw the line between warnings and errors for mismatches, it is never an error. At least the size of the mismatch is reported by the parser. (Sigh.) 4) Not sure about s2ibis2, but have seen this where there are not enough table points in the transition region of a table. Model makers need to keep more points in tables where data is changing (steep slope), and fewer where is changing slowly or not at all, for both I-V and V-t tables. Best regards, Lynne Dr. Lynne Green Cadence Design Systems, Inc. lgreen@cadence.com - -----Original Message----- From: Kim Helliwell [mailto:kimgh@apple.com] Sent: Tuesday, April 02, 2002 10:59 AM To: 'ibis-users@eda.org' Subject: [IBIS-Users] IBIS Imponderables I'm sure I'm not the only person who has wondered about these: 1. Why is a mismatch in the file name an error, rather than a warning? In fact, why does it matter at all? 2. Why are only lowercase letters allowed in an IBIS file name? 3. Why are AC mismatches warnings rather than errors? 4. Why does s2ibis2 appear to generate IBIS models with AC mismatches in the first place? (Judging from the number of IBIS models I've seen that used s2ibis2 and had such problems, it is apparently the norm.) Feel free to provide answers or add your own imponderables. Kim Helliwell Apple Computer kimgh@apple.com 408 974 9936 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 02 Apr 2002 16:36:58 -0500 From: Mike LaBonte Subject: Re: [IBIS-Users] IBIS Imponderables One would expect filename mismatches to be a rare problem. It has been explained to me though, in some IC companies, when an IBIS file is submitted by the model maker for publishing, the first thing the web people do is change the filename. Mike LaBonte At 10:59 AM 4/2/2002 -0800, Kim Helliwell wrote: >I'm sure I'm not the only person who has wondered >about these: > >1. Why is a mismatch in the file name an error, rather than > a warning? In fact, why does it matter at all? > >2. Why are only lowercase letters allowed in an IBIS file name? > >3. Why are AC mismatches warnings rather than errors? > >4. Why does s2ibis2 appear to generate IBIS models > with AC mismatches in the first place? (Judging > from the number of IBIS models I've seen that > used s2ibis2 and had such problems, it is > apparently the norm.) > >Feel free to provide answers or add your own imponderables. > > >Kim Helliwell >Apple Computer >kimgh@apple.com >408 974 9936 > >|------------------------------------------------------------------ >|For help or to subscribe/unsubscribe, email majordomo@eda.org >|with just the appropriate command message(s) in the body: >| >| help >| subscribe ibis >| subscribe ibis-users >| unsubscribe ibis >| unsubscribe ibis-users >| >|or email a written request to ibis-request@eda.org. >| >|IBIS reflector archives exist under: >| >| http://www.eda.org/pub/ibis/email_archive/ Recent >| http://www.eda.org/pub/ibis/users_archive/ Recent >| http://www.eda.org/pub/ibis/email/ E-mail since 1993 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 2 Apr 2002 17:34:45 -0700 From: Al Davis Subject: Re: [IBIS-Users] IBIS Imponderables Here's one I have been wondering about ... Why do people involved with IBIS refer to transient behavior as "AC"? AC has always meant steady state frequency domain to me. |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 2 Apr 2002 16:58:36 -0800 From: Kim Helliwell Subject: Re: [IBIS-Users] IBIS Imponderables That's a good one. I only used the term that way because that's what the IBIS Golden Parser calls it. I assume that everyone is familiar with the error message for "AC mismatch" so it's a bit of shorthand. You are right about it being a misnomer. Kim On Tuesday, April 2, 2002, at 04:34 PM, Al Davis wrote: > Here's one I have been wondering about ... > > Why do people involved with IBIS refer to transient behavior as "AC"? > AC has always meant steady state frequency domain to me. > |------------------------------------------------------------------ > |For help or to subscribe/unsubscribe, email majordomo@eda.org > |with just the appropriate command message(s) in the body: > | > | help > | subscribe ibis > | subscribe ibis-users > | unsubscribe ibis > | unsubscribe ibis-users > | > |or email a written request to ibis-request@eda.org. > | > |IBIS reflector archives exist under: > | > | http://www.eda.org/pub/ibis/email_archive/ Recent > | http://www.eda.org/pub/ibis/users_archive/ Recent > | http://www.eda.org/pub/ibis/email/ E-mail since 1993 > > Kim Helliwell Apple Computer kimgh@apple.com 408 974 9936 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 2 Apr 2002 20:09:36 -0500 From: Chris Rokusek Subject: RE: [IBIS-Users] IBIS Imponderables This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. - ------_=_NextPart_001_01C1DAAC.12EF7E80 Content-Type: text/plain; charset="iso-8859-1" Al, My guess is that it is a carry over from databooks which often use the term "AC characteristics" to describe switching behavior. Chris - -----Original Message----- From: Al Davis [mailto:aldavis@ieee.org] Sent: Tuesday, April 02, 2002 4:35 PM To: ibis-users@eda.org Subject: Re: [IBIS-Users] IBIS Imponderables Here's one I have been wondering about ... Why do people involved with IBIS refer to transient behavior as "AC"? AC has always meant steady state frequency domain to me. |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org with just |the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 - ------_=_NextPart_001_01C1DAAC.12EF7E80 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable RE: [IBIS-Users] IBIS Imponderables

Al,

My guess is that it is a carry over from databooks = which often use the
term "AC characteristics" to describe = switching behavior.

Chris

-----Original Message-----
From: Al Davis [mailto:aldavis@ieee.org]
Sent: Tuesday, April 02, 2002 4:35 PM
To: ibis-users@eda.org
Subject: Re: [IBIS-Users] IBIS Imponderables

Here's one I have been wondering about ...

Why do people involved with IBIS refer to transient = behavior as "AC"?
AC has always meant steady state frequency = domain to me.
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- ------_=_NextPart_001_01C1DAAC.12EF7E80-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 3 Apr 2002 00:31:40 -0800 From: "Jeremy Plunkett" Subject: RE: [IBIS-Users] IBIS Imponderables Hi Kim, I have never been involved in the IBIS specification process, but I have built a lot of models, and here are my best-guess answers to your questions... - -----Original Message----- From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org]On Behalf Of Kim Helliwell Sent: Tuesday, April 02, 2002 10:59 AM To: 'ibis-users@eda.org' Subject: [IBIS-Users] IBIS Imponderables I'm sure I'm not the only person who has wondered about these: 1. Why is a mismatch in the file name an error, rather than a warning? In fact, why does it matter at all? This was probably intended to prevent people from modifying the filename from the original (or make it more difficult, at least). This is because an IBIS file is similar to a specification (more detailed, but less official) and semiconductor vendors do not want modified versions of their IBIS models floating around. There should be one most current revision of an IBIS model for a given part, and if people are prevented from renaming the file then it is easier to confirm that they are all using the same file. Of course if model users want to work around this they can (and do), but they have to go through the hassle of changing the name in 2 places. 2. Why are only lowercase letters allowed in an IBIS file name? As others mentioned, this helps ease transfer between operating systems. 3. Why are AC mismatches warnings rather than errors? The mismatch that this indicates is between the initial or final voltage of a VT curve and the predicted (steady-state)operating point based on the intersection of the IV curve with the load line for the VT curve load resistance. There are 2 likely reasons why this mismatch occurs: 1) the model maker trimmed off too much of the initial portion of the VT curve data before the edge, and either cut off the very beginning of the transition or set the start point of the VT curve data in the middle of a "pre-shoot" hump in the data (bounce on the signal that occurs prior to switching due to capacitive coupling between the gate and source/drain terminals of the output transistors). 2) the model maker set the end of the VT curves at a point where the signal had not yet completely settled at one or more of the PVT corners. This is often unavoidable if the buffer will be used in a very fast switching environment, since some simulation programs (specifically Hspice, to my knowledge, and possibly others) will give erroneous waveforms if the VT curves are longer than the pulse width when the model is used in simulation. This requires that a buffer which will be used at a frequency of 200MHz (2.5ns pulse width) must have VT curves less than 2.5ns in duration, maybe 10-15% less if the duty cycle or frequency will be varied in simulations. Neither of these situations has a large effect on the accuracy of the simulation results with any simulators I've used, since in the 1st case any errors in the waveform occur prior to the portion of the edge which crosses the receiver thresholds and in the 2nd case the waveform errors would occur while the output voltage is at a steady-state high or low. The sort of error that does occur depends on exactly what the simulator does in the face of the inconsistent VT data, but I am fairly sure that most if not all simulators either modify the curves with interpolated values or revert to some approximation of the IBIS 1.0 (no VT curves) algorithm at the discontinuities and just apply the VI curves to the load, which will result in a fairly smooth transition either way. 4. Why does s2ibis2 appear to generate IBIS models with AC mismatches in the first place? (Judging from the number of IBIS models I've seen that used s2ibis2 and had such problems, it is apparently the norm.) The 2 situations above are very common, the 1st case happens more often with slow-speed logic and inexperienced model makers who determine the beginning of the transition in an arbitrary manner, the 2nd case is more common with very high speed logic and is often unavoidable. Since avoiding the mismatch warning involves modifying the VT curves from the original data based on spice or measurement, whether to do so in a given case is a judgment call, and is probably not worth doing unless there is a significant chance that leaving the model with the mismatch will result in simulator errors. Feel free to provide answers or add your own imponderables. Kim Helliwell Apple Computer kimgh@apple.com 408 974 9936 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 3 Apr 2002 08:33:03 -0500 From: "Ingraham, Andrew" Subject: RE: [IBIS-Users] IBIS Imponderables Another possible reason for the error-vs-warning differentiation, on top of those already mentioned.... When a mistake is easily avoidable and/or correctable, and not the result of variations from one (simulator) implementation to another, they would be errors. A file name error is easily and permanently fixed. On the other hand, an "AC" mismatch depends to some degree on the interpolation algorithm used by the simulator. Also, miniscule voltage errors can sometimes cause enormous percentage differences, but shouldn't prevent the model from being used (without an expert handy to tweak the tables). Regards, Andy |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Thu, 4 Apr 2002 10:43:03 -0800 From: "Mirmak, Michael" Subject: RE: [IBIS-Users] Using Differential IBIS Buffers in HSPICE This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. - ------_=_NextPart_001_01C1DC08.8D995590 Content-Type: text/plain; charset="iso-8859-1" Tim, There are known differences in how recent versions of HSPICE (2001.2 vs. 2001.4) treat differential IBIS models. Try consulting the Avant! website or your local rep. for the latest usage recommendations on 2001.4. We've had success by adding the following line to our B-element calls: +hsp_ver=2001.2 This will force HSPICE to use the 2001.2 IBIS simulation engine. Try it and see if your results meet expectations. Good luck! - - Michael Mirmak, Intel Corp. -----Original Message----- From: Timothy Coyle [mailto:Timothy.Coyle@nsc.com] Sent: Tuesday, April 02, 2002 10:09 AM To: ibis-users@server.eda.org Subject: [IBIS-Users] Using Differential IBIS Buffers in HSPICE Hi, I am trying to use differential output IBIS buffers in HSPICE. I set up independent voltage sources on each of the inverting and non-inverting output buffer. I put 100 ohms across the outputs since it is LVDS. I'm getting some strange results. Both buffers have non-inverting polarity and the voltage swing is way off for LVDS. Any help would be appreciated. Thanks in advance, Tim - ------_=_NextPart_001_01C1DC08.8D995590 Content-Type: text/html; charset="iso-8859-1"

Tim,

There are known differences in how recent versions of HSPICE (2001.2 vs. 2001.4) treat differential IBIS models. Try consulting the Avant! website or your local rep. for the latest usage recommendations on 2001.4. We've had success by adding the following line to our B-element calls:

+hsp_ver=2001.2

This will force HSPICE to use the 2001.2 IBIS simulation engine. Try it and see if your results meet expectations.

Good luck!

- Michael Mirmak, Intel Corp.

-----Original Message-----
From: Timothy Coyle [mailto:Timothy.Coyle@nsc.com]
Sent: Tuesday, April 02, 2002 10:09 AM
To: ibis-users@server.eda.org
Subject: [IBIS-Users] Using Differential IBIS Buffers in HSPICE

Hi,
I am trying to use differential output IBIS buffers in HSPICE. I set up independent voltage sources on each of the inverting and non-inverting output buffer.
I put 100 ohms across the outputs since it is LVDS. I'm getting some strange results. Both buffers have non-inverting polarity and the voltage swing is way off
for LVDS. Any help would be appreciated.

Thanks in advance,
Tim

- ------_=_NextPart_001_01C1DC08.8D995590-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Fri, 5 Apr 2002 16:32:15 -0500 From: "Timothy Coyle" Subject: [IBIS-Users] Measuring Ccomp in HSPICE This is a multipart message in MIME format. - --=_alternative 00768B0D85256B92_= Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hello, I'm looking for a way to obtain ccomp for inputs/outputs in HSPICE for IBIS. I would like to be able to get ccomp min and max values from simulation. Thanks, Tim - --=_alternative 00768B0D85256B92_= Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit
Hello,
I'm looking for a way to obtain ccomp for inputs/outputs in HSPICE for IBIS. I would like to be able to get ccomp min and max values from
simulation.

Thanks,
Tim
- --=_alternative 00768B0D85256B92_=-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 9 Apr 2002 14:39:47 -0400 From: "Michael Dotson" Subject: [IBIS-Users] test..please ignore Just a test msg Regards, Mike Dotson Endicott Worldwide Field Design Center 607-752-5379 (tl 852) |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 9 Apr 2002 15:36:48 -0400 From: "Michael Dotson" Subject: [IBIS-Users] Using the '.ibis' (note the dot) in HSPICE I have spent the last 2 days puzzling over how to use the ' .ibis ' call in hspice. Using the basic ibis buffer works ok, but this other command was there to try as well. The ibis device I have is a basic TS TTL buffering device that says it is 2.1 compatible. When hspice runs I can see that it allocates a buffer to each input and output pin. However, the stim I put on the input pin does not get propagated to the output pin. I can see the input buffer switching a-ok, but the output buffer does not. I have even tried different enable pin values to see if that had an effect. What seem to be missing is the 'hook' to drive the output buffers nd_in port. Actually, I do not even see a port named nd_in for the output buffers. I can see the pc and pd and en pins OK though. Can someone shed some light on my confusion? thanks, Mike Dotson IBM Endicott Worldwide Field Design Center 607-752-5379 (tl 852) |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 09 Apr 2002 17:12:48 -0400 From: Mark Bossard Subject: Re: [IBIS-Users] Using the '.ibis' (note the dot) in HSPICE I would suggest checking out the Hspice Device Models Manual. It should be part of the normal Hspice electronic documentation package. It has a fair description and examples of using .ibis . The Device Models Manual tells you what the node names are (or should be). The names of the input and output nodes for the buffers are: INPUT and INPUT_ECL buffers signal name of pin ( in ) bufn_ ( outofin ) Other types of buffers bufn_ ( in ) signal name of pin ( out ) n is 1 if this pin is the first pin defined in the [Pin] keyword. n is 2 if this pin is the second pin. and so on. Note: If the buffer has an enable terminal, you must create a node named buffer_name_en to enable the buffer. Good Luck, Mark Bossard Michael Dotson wrote: > > I have spent the last 2 days puzzling over how to use the ' .ibis ' call in > hspice. > Using the basic ibis buffer works ok, but this other command was there to > try as well. > > The ibis device I have is a basic TS TTL buffering device that says it is > 2.1 compatible. > > When hspice runs I can see that it allocates a buffer to each input and > output pin. > However, the stim I put on the input pin does not get propagated to the > output pin. > I can see the input buffer switching a-ok, but the output buffer does not. > I have even tried different enable pin values to see if that had an effect. > > What seem to be missing is the 'hook' to drive the output buffers nd_in > port. > Actually, I do not even see a port named nd_in for the output buffers. I > can > see the pc and pd and en pins OK though. > > Can someone shed some light on my confusion? > > thanks, > Mike Dotson > IBM Endicott Worldwide Field Design Center 607-752-5379 (tl 852) > > |------------------------------------------------------------------ > |For help or to subscribe/unsubscribe, email majordomo@eda.org > |with just the appropriate command message(s) in the body: > | > | help > | subscribe ibis > | subscribe ibis-users > | unsubscribe ibis > | unsubscribe ibis-users > | > |or email a written request to ibis-request@eda.org. > | > |IBIS reflector archives exist under: > | > | http://www.eda.org/pub/ibis/email_archive/ Recent > | http://www.eda.org/pub/ibis/users_archive/ Recent > | http://www.eda.org/pub/ibis/email/ E-mail since 1993 - -- ======================================================================== | Mark Bossard | Atmel Corporation | | Direct Phone: (410) 423-4352 | Chesapeake Design Center | | Main Phone: (410) 423-4300 | 8820 Columbia 100 Parkway | | Fax: (410) 423-4302 | Suite 300 | | Email: mbossard@atmel.com | Columbia, MD 21045 | ======================================================================== |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 09 Apr 2002 18:18:56 -0400 From: Mike LaBonte Subject: Re: [IBIS-Users] Using the '.ibis' (note the dot) in HSPICE The actual node names don't matter, do they? You can name them anything you want as long as the terminal positions are correct in the B element call. It wouldn't be SPICE if the actual names mattered. I was wondering if Mike is using the power=off parameter, which causes the power and ground terminal to be used to supply current to the buffer. This has never worked for me, and I have yet to find an example of a circuit that works that way. Mike At 05:12 PM 4/9/2002 -0400, Mark Bossard wrote: >I would suggest checking out the Hspice Device Models Manual. >It should be part of the normal Hspice electronic documentation package. >It has a fair description and examples of using .ibis . > >The Device Models Manual tells you what the node names are (or should >be). > >The names of the input and output nodes for the buffers are: >INPUT and INPUT_ECL buffers signal name of pin ( in ) >bufn_ ( outofin ) >Other types of buffers bufn_ ( in ) signal name of pin ( >out ) >n is 1 if this pin is the first pin defined in the [Pin] >keyword. >n is 2 if this pin is the second pin. and so on. >Note: If the buffer has an enable terminal, you must create a node named >buffer_name_en to enable the buffer. > >Good Luck, > >Mark Bossard > > > >Michael Dotson wrote: > > > > I have spent the last 2 days puzzling over how to use the ' .ibis ' call in > > hspice. > > Using the basic ibis buffer works ok, but this other command was there to > > try as well. > > > > The ibis device I have is a basic TS TTL buffering device that says it is > > 2.1 compatible. > > > > When hspice runs I can see that it allocates a buffer to each input and > > output pin. > > However, the stim I put on the input pin does not get propagated to the > > output pin. > > I can see the input buffer switching a-ok, but the output buffer does not. > > I have even tried different enable pin values to see if that had an effect. > > > > What seem to be missing is the 'hook' to drive the output buffers nd_in > > port. > > Actually, I do not even see a port named nd_in for the output buffers. I > > can > > see the pc and pd and en pins OK though. > > > > Can someone shed some light on my confusion? > > > > thanks, > > Mike Dotson > > IBM Endicott Worldwide Field Design Center 607-752-5379 (tl 852) > > |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 10 Apr 2002 10:03:14 -0400 From: "Ingraham, Andrew" Subject: RE: [IBIS-Users] Using the '.ibis' (note the dot) in HSPICE I was going to comment on this too, but I'm confused exactly what he's doing. There's no inherent connection between an input buffer and an output buffer. IBIS doesn't model whole devices, such as a complete gate. It models just the input alone, as seen from outside the chip; or just the output alone; but there is no connection from an input (of one model) to an output (of the same or a different model). Signals do not propagate through IBIS models. That being said, HSPICE's implementation does use buffer elements through which signals effectively propagate with zero delay; but one of those signals is pure binary. For example, if you model an input buffer ("buffer=input"), the signal that the simulation applies to the "nd_in" node (which represents the device's input pad) does appear, in binary voltage form, at the "nd_out_of_in" node. Merely as a convenience to you. This signal has no physical meaning whatsoever. For the output buffer ("buffer=output"), *you* need to drive the "nd_in" pin, with a binary voltage source. Again, the signal has no physical meaning. It is just a way to get the buffer element to do something. As for the node names, the names given in the HSPICE manual to represent syntax, such as "nd_in", are just place-holders for the names you use. "nd_in" itself has no special meaning to HSPICE. Recall the syntax for resistors, which is: Rxxx n1 n2 ... Nodes "n1" and "n2" are place-holders. Your IBIS model could look like: BTTL 1 2 3 4 5 6 ... or: B_xyz VccPad GndPad SigPad BinSig ... If you instantiate more than one IBIS device, make sure not to use the same node names on all of them, unless you really wanted them all shorted together! Andy |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 10 Apr 2002 11:18:12 -0400 From: "Michael Dotson" Subject: RE: [IBIS-Users] Using the '.ibis' (note the dot) in HSPICE The confusion was coming from the 'Device Models Ref' manual decription of the Hspice implementation of the 'automagic' buffer instantiation when the ' .ibis ' command is used. From the comments here, I understand that I need to stim whatever buffer I wanted to look at. Now that I realize that the 'bufn_#' is either an input or output node, depending in the buffer type, I have been able to proceed forward. Many thanks for the help, Mike Dotson IBM Endicott Worldwide Field Design Center 607-752-5379 (tl 852) |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 10 Apr 2002 12:30:22 -0400 From: Mark Bossard Subject: Re: [IBIS-Users] Using the '.ibis' (note the dot) in HSPICE To clear up a little confusion.... '.ibis' is a new command in Hspice (2001.4.1 is the first appearance I think) that serves this function... >>The Avant! True-Hspice models implement buffers as a standard b element. But to support simulation of IBIS >>models using .ebd and .pkg, True-Hspice IBIS models include another component that creates buffers for an >>integrated circuit. >>The .ibis command adds a buffer to the netlist for every pin, according to the signal_name and model_name >>defined in the [Pin] keyword in the .ibs file. Oddly enough.... you don't need to use .ebd or .pkg to use .ibis, and I don't believe you need to use .ibis to use .ebd and .pkg (as they existed in Hspice before .ibis). As it is a new command, there is little documentation on it (only about 6 spotty pages). It's enough of a departure from the normal B model ibis buffer in Hspice that it gets rather confusing to try to use it. I looked at it, tried using it a few times, and then gave up and decided it was a waste of my valuable time (without better documentation and/or support from Avanti). - -Mark Bossard - - - -- ======================================================================== | Mark Bossard | Atmel Corporation | | Direct Phone: (410) 423-4352 | Chesapeake Design Center | | Main Phone: (410) 423-4300 | 8820 Columbia 100 Parkway | | Fax: (410) 423-4302 | Suite 300 | | Email: mbossard@atmel.com | Columbia, MD 21045 | ======================================================================== |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 10 Apr 2002 15:30:29 -0400 From: "Michael Dotson" Subject: Re: [IBIS-Users] Using the '.ibis' (note the dot) in HSPICE The final word is I discovered that the IV tables were bad (wrong sign) in the ibis model I was using. Everything looks OK after I fixed the tables. Thanks, Mike Dotson IBM Endicott Worldwide Field Design Center 607-752-5379 (tl 852) |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Thu, 11 Apr 2002 21:51:24 -0400 From: Guy deBurgh Subject: [IBIS-Users] IBIS Summit meeting at Dac 2002 This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. - ------_=_NextPart_001_01C1E1C4.ADDF0B80 Content-Type: text/plain; charset="iso-8859-1" D A C 2 0 0 2 I B I S S U M M I T M E E T I N G F I R S T A N N O U N C E M E N T DATE: Thursday, June 13, 2002 TIME: 8:30 AM - 5:00 PM CITY: New Orleans, Louisiana LOCATION: Hilton Hotel, New Orleans Riverside, next to Ernest N. Morial Convention Center where the Design Automation Conference (DAC) is being held. ROOM: To be announced. LUNCH: Free Refreshments and Lunch will be provided. AGENDA: The agenda is being planned. Some possible items are: Election of Officers for 2002 - 2003 Connector Specification Multi-Lingual Modeling EMI Modeling IBIS Version 4.0 Review IBIS Quality Modeling Problems and Solutions We welcome presentations and discussions on IBIS topics. DAC 2002: DAC is scheduled Monday - Friday, June 10 - 14, 2002. The exhibitor portion is open from Monday - Wednesday. For more information on DAC 2002 activities, housing, etc., visit the DAC URL: DAC URL: http://www.dac.com/ CALL FOR PRESENTATIONS: We are also open to technical presentations (usually 30 minutes or less) related to any current IBIS activity and to future IBIS needs. Contact Guy de Burgh regarding your presentation: Presenter: Title: Estimated Time: We are providing an LCD Projector and an Overhead Projector. Please plan to bring foils for backup, if needed. We would like you to provide handouts for the meeting (about 25) and also an electronic copy for archiving. CALL FOR ATTENDEES: Please let Guy de Burgh know if you are planning to attend so we have an estimate on food requirements. CONTACT: Guy de Burgh IBIS Secretary gdeburgh@innoveda.com (805) 988-8250 ext. 6823 - ------_=_NextPart_001_01C1E1C4.ADDF0B80 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable IBIS Summit meeting at Dac 2002

&nb= sp; D A C 2 0 0 2 I B I S S U = M M I T M E E T I N G
&nb= sp; F = I R S T A N N O U N C E M E N T

DATE: Thursday, June = 13, 2002
TIME: 8:30 AM - 5:00 = PM

CITY: New Orleans, = Louisiana

LOCATION: Hilton Hotel, New Orleans Riverside, = next to Ernest N. Morial

= Convention Center where the Design Automation Conference
= (DAC) is being held.

ROOM: To be = announced.

LUNCH: Free Refreshments and = Lunch will be provided.

AGENDA: The agenda is being = planned. Some possible items are:

&nb= sp; Election of Officers for 2002 - 2003

&nb= sp; Connector Specification

&nb= sp; Multi-Lingual Modeling

&nb= sp; EMI Modeling

&nb= sp; IBIS Version 4.0 Review

&nb= sp; IBIS Quality

&nb= sp; Modeling Problems and Solutions

= We welcome presentations and discussions on IBIS topics.

DAC 2002: DAC is scheduled Monday - Friday, = June 10 - 14, 2002.
           = The exhibitor portion is open from Monday - Wednesday.
           = For more information on DAC 2002 activities, housing, etc.,
           = visit the DAC URL:

DAC URL: http://www.dac.com/

CALL FOR PRESENTATIONS:

           = We are also open to technical presentations (usually 30
minutes
           = or less) related to any current IBIS activity and to future
IBIS
           = needs.

= Contact Guy de Burgh regarding your presentation:

          &nb= sp;   Presenter:
          &nb= sp;   Title:
          &nb= sp;   Estimated Time:

= We are providing an LCD Projector and an Overhead Projector.
= Please plan to bring foils for backup, if needed.

= We would like you to provide handouts for the meeting (about
25)
= and also an electronic copy for archiving.

CALL FOR ATTENDEES:

= Please let Guy de Burgh know if you are planning to attend so

= we have an estimate on food requirements.

CONTACT:   Guy de Burgh
           = IBIS Secretary
           = gdeburgh@innoveda.com
           = (805) 988-8250 ext. 6823

- ------_=_NextPart_001_01C1E1C4.ADDF0B80-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Fri, 12 Apr 2002 08:25:34 -0700 From: "Peters, Stephen" Subject: [IBIS-Users] Agenda, IBIS Teleconference Meeting 4/19 IBIS Open Forum Meeting Agenda for 4/19/02 Bridge Number Reservation # Passcode 1-888-316-5901 N/A 7095323 (International Dial-In: 1-617-801-9781) All meetings are 8:00 AM to 9:55 AM Pacific Time. When you call into the meeting, ask for the IBIS Open Forum hosted by Stephen Peters and give the Reservation Number and Passcode. 8:00 Check-In, Intros, Announcements Peters - Intros of New IBIS Participants, Meeting Quorum Peters - Membership Update and Treasurers Report Fleming/Ross - Review of Previous Meeting's Minutes (and ARs) Peters - Miscellany/Announcements All - Press & Web Page Updates Huq, All - New Models Available, Library Update Leventhal, All - Opens for New Issues All 8:15 Administrative and Project Discussions International/External Progress - IEC 62014-3 (ICEM) Integrated Circuits Electromagnetic Model Proposal (IEC 93/67/NP IBIS and EMC Simulation) Perrin/Peters - JEDEC JC-16 Modeling and Testing Sessions - T10, Project 1414-DT - SCSI Signal Modeling Barnes Design Automation Conference IBIS Summit Meeting Ross IBIS Qualification Committee Katz IBIS Model Review Committee Ross Majordomo Update Angulo New Administrative Issues All 8:45 Technical Discussion IBIS Version 4.0 Review Peters Connector & Futures Group Report Peters BIRD 74 - EMI Parameters DeBurg BIRD 75 - Multi-Lingual IBIS Modeling Support Ross ibischk3 Status Ross - BUG68 - False Messages with Repeated Voltages Mirmak New Technical Issues All 9:50 Wrap Up and Next Meetings Plans Peters 9:55 Sign Off |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Fri, 12 Apr 2002 10:46:51 -0700 (PDT) From: Syed Huq Subject: [IBIS-Users] ERROR in .pkg file Hi, The IBIS parser gives the following ERROR on a .pkg file: ERROR (line 5100) - This Row Column Index defines an entry in the lower matrix triangle. ERROR (line 5101) - This Row Column Index defines an entry in the lower matrix triangle. 5098 [Row] AV35 5099 AV35 1.60634E-08 5100 AV34 8.46141E-09 <--Error on this line 5101 AW35 1.00513E-08 <--Error on this line 5102 [Row] F23 Can anyone give a bit more detailed explanation of what this ERROR message from the parser means and how to debug this ? I wish the parser output was more descriptive..What is a lower matrix triangle.. Syed |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Fri, 12 Apr 2002 14:20:28 -0500 From: "Dunbar, Tony" Subject: RE: [IBIS-Users] ERROR in .pkg file Syed, A lower matrix triangle refers to the row/column section of a matrix below the main diagonal. Only the upper-half matrix should be used. Symmetry in the usual Maxwell matrix means this is sufficient. The numbers in your example look like they are probably from the inductance matrix, but I'm guessing just from the scale of the numbers. What type of (inductance) matrix are you meant to be using, according to what is specified in the .pkg file? Banded, Sparse or Full? The format of your example looks like Sparse. I'm guessing that the source of your problem is that the index AV34 is alpanumerically before the current [Row] AV35 and this conflicts with the ordering defined in the [Pin Numbers] section and the reconstruction of the matrix attempts to place it in the lower-half. Errr, unless there's a bug in the parser!? Regards, Tony - -----Original Message----- From: Syed Huq [mailto:shuq@cisco.com] Sent: Friday, April 12, 2002 12:47 PM To: ibis-users@server.eda.org Subject: [IBIS-Users] ERROR in .pkg file Hi, The IBIS parser gives the following ERROR on a .pkg file: ERROR (line 5100) - This Row Column Index defines an entry in the lower matrix triangle. ERROR (line 5101) - This Row Column Index defines an entry in the lower matrix triangle. 5098 [Row] AV35 5099 AV35 1.60634E-08 5100 AV34 8.46141E-09 <--Error on this line 5101 AW35 1.00513E-08 <--Error on this line 5102 [Row] F23 Can anyone give a bit more detailed explanation of what this ERROR message from the parser means and how to debug this ? I wish the parser output was more descriptive..What is a lower matrix triangle.. Syed |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Mon, 15 Apr 2002 13:48:56 -0400 From: "Timothy Coyle" Subject: [IBIS-Users] R fixture with Differential This is a multipart message in MIME format. - --=_alternative 00629A5685256B9C_= Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hi, I am trying to extract V-T data from a differential buffer. The outputs are terminated by 100 Ohms. (LVDS) In order to keep the outputs operating correctly, each output is tied to R/2 to Vos. What should I specify in IBIS for R_fixture? Is it 50 Ohms to 1.2V, as the data is taken? Or is it 100 ohms to 1.2V? It seems when I specify R_fixture as 50 ohms, I get a small 20 mV glitch on my edges when I run the IBIS file in HSPICE. (not sure if this is causing it or not) Any comments appreciated. Tim - --=_alternative 00629A5685256B9C_= Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit
Hi,
I am trying to extract V-T data from a differential buffer. The outputs are terminated by 100 Ohms. (LVDS) In order to keep the outputs operating correctly, each output is tied to
R/2 to Vos. What should I specify in IBIS for R_fixture? Is it 50 Ohms to 1.2V, as the data is taken? Or is it 100 ohms to 1.2V? It seems when I specify R_fixture as 50 ohms,
I get a small 20 mV glitch on my edges when I run the IBIS file in HSPICE. (not sure if this is causing it or not)

Any comments appreciated.

Tim
- --=_alternative 00629A5685256B9C_=-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Mon, 15 Apr 2002 13:07:29 -0500 From: "Yaping Zhou" Subject: [IBIS-Users] SSO effect Hi, all: This is an excerption from IBIS Cookbook. I have one question about it, and need your help. "Inclusion of SSO Effects Closely related to the discussion on model limits is the decision on how to include Simultaneous Switching Output (SSO) effects. SSO effects can be included explicitly in a model by measuring the I/V and edge rate characteristics under SSO conditions. For example, a buffers I/V characteristic can be measured with all the adjacent buffers turned on and sinking current, or the buffers edge rate may be measured while adjacent buffers are also switching. Alternatively, a model that represents a single buffer in isolation may be created, then several buffers may be connected to a common power or ground rail via the [Pin Mapping] keyword. The former method (including SSO effects in the models' I/V and edge rate tables) has the advantage that the resulting model is straight forward to verify and less dependent on any particular simulators capability. Note however, the [Pin Mapping] keyword method does give the user the ability to perform explicit ground bounce simulations and devise specific 'what if' scenarios. " When [Pin Mapping] is used, do we still need to measure V-I under SSO condition? I think we should because we need to know how buffers respond when voltage droop happens due to simultanuous switching. Thanks in advance. Yaping Zhou Motorola Inc. |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 17 Apr 2002 08:58:22 -0700 From: "Peters, Stephen" Subject: RE: [IBIS-Users] Measuring Ccomp in HSPICE This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. - ------_=_NextPart_001_01C1E628.B33F6080 Content-Type: text/plain; charset="ISO-8859-1" Hello Tim: There are a number of methods, but whatever method is chosen recognize that C_comp of an output buffer is a function of the pad voltage and transistor bias. I.e. just extracting the min and max pad capacitance from a placed and routed buffer design will not be as accurate as doing an in circuit test. One method I've used for tri-stateable buffers and input buffers is as follows: 1. In your simulation environment, apply power to the buffer and set the controls so that the output is in a high impedance state. 2. Thru a series resistor, connect a pulse source to the buffers input or output node. 3. apply a very fast (<5ps rising edge) step to the resistor. Amplitude of the step should be close to VCC. Observe the RC waveform at the output or input node of the buffer, and calculate the C_comp value from the standard RC time constant equation. Regards, Stephen - -----Original Message----- From: Timothy Coyle [mailto:Timothy.Coyle@nsc.com] Sent: Friday, April 05, 2002 1:32 PM To: ibis-users@server.eda.org Subject: [IBIS-Users] Measuring Ccomp in HSPICE Hello, I'm looking for a way to obtain ccomp for inputs/outputs in HSPICE for IBIS. I would like to be able to get ccomp min and max values from simulation. Thanks, Tim - ------_=_NextPart_001_01C1E628.B33F6080 Content-Type: text/html; charset="ISO-8859-1"

Hello Tim:

There are a number of methods, but whatever method is chosen recognize that C_comp of an output buffer is a function of the pad voltage and transistor bias. I.e. just extracting the min and max pad capacitance from a placed and routed buffer design will not be as accurate as doing an in circuit test. One method I've used for tri-stateable buffers and input buffers is as follows:

1. In your simulation environment, apply power to the buffer and set the controls so that the output is in a high impedance state.

2. Thru a series resistor, connect a pulse source to the buffers input or output node.

3. apply a very fast (<5ps rising edge) step to the resistor. Amplitude of the step should be close to VCC. Observe the RC waveform at the output or input node of the buffer, and calculate the C_comp value from the standard RC time constant equation.

Regards,

Stephen

-----Original Message-----
From: Timothy Coyle [mailto:Timothy.Coyle@nsc.com]
Sent: Friday, April 05, 2002 1:32 PM
To: ibis-users@server.eda.org
Subject: [IBIS-Users] Measuring Ccomp in HSPICE

Hello,
I'm looking for a way to obtain ccomp for inputs/outputs in HSPICE for IBIS. I would like to be able to get ccomp min and max values from
simulation.

Thanks,
Tim

- ------_=_NextPart_001_01C1E628.B33F6080-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Fri, 19 Apr 2002 14:23:59 -0400 From: "Timothy Coyle" Subject: [IBIS-Users] I-V vs V-T curves This is a multipart message in MIME format. - --=_alternative 006604BE85256BA0_= Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hi, I am trying to determine where my mismatch end points are coming from in an IBIS file I am creating. How do I get the end points from the pullup and pulldown I-V data so I can compare them to the endpoints in my V-T curves? (load condition for V-T data is 50 ohms to 1.2V with endpoints 1.0V and 1.4V) Thanks, Tim - --=_alternative 006604BE85256BA0_= Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit
Hi,
I am trying to determine where my mismatch end points are coming from in an IBIS file I am creating. How do I get the end points from the pullup and pulldown I-V data
so I can compare them to the endpoints in my V-T curves? (load condition for V-T data is 50 ohms to 1.2V with endpoints 1.0V and 1.4V)

Thanks,
Tim
- --=_alternative 006604BE85256BA0_=-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Mon, 22 Apr 2002 07:54:12 +0200 From: Lenski Eckhard Subject: AW: [IBIS-Users] I-V vs V-T curves This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. - ------_=_NextPart_001_01C1E9C2.20D9DAC0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable Hello Tim, =20 I assume that you are modeling an LVDS-output. =20 Normaly ( cmos ) you compare the crossing of the 50Ohmload curves with = the pullup - pulldown curves=20 =20 - - 50 Ohm to Gnd crossing with pullup curve - - 50 Ohm to Vcc crossing with pulldown curve =20 and the rising falling waveforms are measured with a 50 Ohm load to = GND and to VCC. =20 For LVDS you have to look for the crossing of your 50 Ohm to 1.2V = load-curve with the pullup and pulldown curves=20 ( so you havve to use the same loadcurve twice )=20 and then there should be no ( or no significant ) mismatch. =20 By the way, I think the ibis-checker is always using 50 ohm to gnd and = 50 Ohm to vcc. =20 =20 If you have further questions, please let me know. =20 regards=20 Eckhard Lenski=20 =20 Eckhard Lenski=20 Siemens AG=20 ICN WN OP TDC TC3=20 81359 M=FCnchen=20 Tel: 0049 89 722 27776=20 Fax: 0049 89 722 44692=20 Email: eckhard.lenski@icn.siemens.de=20 - -----Urspr=FCngliche Nachricht----- Von: Timothy Coyle [mailto:Timothy.Coyle@nsc.com] Gesendet: Freitag, 19. April 2002 20:24 An: ibis-users@eda.org Betreff: [IBIS-Users] I-V vs V-T curves Hi,=20 I am trying to determine where my mismatch end points are coming from = in an IBIS file I am creating. How do I get the end points from the = pullup and pulldown I-V data=20 so I can compare them to the endpoints in my V-T curves? (load = condition for V-T data is 50 ohms to 1.2V with endpoints 1.0V and 1.4V) = Thanks,=20 Tim=20 - ------_=_NextPart_001_01C1E9C2.20D9DAC0 Content-Type: text/html; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable

Hello=20 Tim,

I=20 assume that you are modeling an LVDS-output.

Normaly ( cmos ) you compare the crossing = of the=20 50Ohmload curves with the pullup - pulldown curves

- 50=20 Ohm to Gnd crossing with pullup curve

- 50=20 Ohm to Vcc crossing with pulldown curve

and=20 the rising falling waveforms are measured with a 50 Ohm load to = GND and to=20 VCC.

For=20 LVDS you have to look for the crossing of your 50 Ohm to 1.2V =20 load-curve with the pullup and pulldown curves =

(=20 so you havve to use the same loadcurve twice = )

and=20 then there should be no ( or no significant ) =20 mismatch.

By the=20 way, I think the ibis-checker is always using 50 ohm to gnd = and 50 Ohm=20 to vcc.

If you=20 have further questions, please let me know.

regards

Eckhard Lenski

Eckhard Lenski =
Siemens AG
ICN = WN OP TDC=20 TC3
81359 = M=FCnchen=20
Tel: = 0049 89 722=20 27776
Fax: =20 0049 89 722 44692
Email: =20 eckhard.lenski@icn.siemens.de

-----Urspr=FCngliche Nachricht-----
Von: Timothy = Coyle=20 [mailto:Timothy.Coyle@nsc.com]
Gesendet: Freitag, 19. April = 2002=20 20:24
An: ibis-users@eda.org
Betreff: = [IBIS-Users] I-V vs=20 V-T curves

Hi,=20
I am trying to determine where = my mismatch=20 end points are coming from in an IBIS file I am creating. = How do I=20 get the end points from the pullup and pulldown I-V data =
so I can compare them to the endpoints in = my V-T=20 curves? (load condition for V-T data is 50 ohms to 1.2V with = endpoints 1.0V=20 and 1.4V)

Thanks,
Tim

- ------_=_NextPart_001_01C1E9C2.20D9DAC0-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Mon, 22 Apr 2002 14:50:40 -0400 From: "Timothy Coyle" Subject: [IBIS-Users] Input ESD Structures This is a multipart message in MIME format. - --=_alternative 00689DE285256BA3_= Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hello, When I get a SPICE netlist from the design team to do a spi2ibis translation, the ESD structures have ideal diodes (no resistance) which leads to kAmps in my power and ground clamp curves. So I put a series resistor of 1-3 Ohms on the input of the ESD pad (and sometimes the ground node of the ESD pad) to try to limit the current. While this approach works, my simulated data does not match up with data taken from the bench. The lab data at one point is 4.3mA and the simulated data at the same point is 160uA for a ground clamp curve. Changing the resistor value doesn't give me the right current either. Does anyone have any comments/suggestions on this approach? Also, I'm wondering what type of affect on my input model the magnitudes of my power and ground clamp curves have. Does it matter to a simulator if the ground clamp current is 4.3mA or 160uA? It seems the most important parameter for an input model is Ccomp. Has anyone done any work on this they would like to share? Many thanks again to those who respond, Tim - --=_alternative 00689DE285256BA3_= Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit
Hello,
When I get a SPICE netlist from the design team to do a spi2ibis translation, the ESD structures have ideal diodes (no resistance) which leads to kAmps in my
power and ground clamp curves. So I put a series resistor of 1-3 Ohms on the input of the ESD pad (and sometimes the ground node of the ESD pad) to try to limit
the current. While this approach works, my simulated data does not match up with data taken from the bench. The lab data at one point is 4.3mA and the simulated
data at the same point is 160uA for a ground clamp curve. Changing the resistor value doesn't give me the right current either. Does anyone have any
comments/suggestions on this approach?

Also, I'm wondering what type of affect on my input model the magnitudes of my power and ground clamp curves have. Does it matter to a simulator if the ground clamp
current is 4.3mA or 160uA? It seems the most important parameter for an input model is Ccomp. Has anyone done any work on this they would like to share?

Many thanks again to those who respond,

Tim
- --=_alternative 00689DE285256BA3_=-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 23 Apr 2002 11:28:33 -0400 From: "Lynne Green" Subject: RE: [IBIS-Users] Input ESD Structures This is a multi-part message in MIME format. - ------_=_NextPart_001_01C1EADB.8733F552 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hello, Tim, =20 The 3 most significant DC parameters in the diode model: IS: "reverse leakage" current, adjusted to give correct forward current at low bias voltage (V<0.4V in silicon). Ranges from around 1e-16 for signal diodes to >1e-9 for power diodes. N: ideality factor, adjusted to give correct forward current at medium bias (0.5V to 0.6V in silicon). Usually 10.7V in silicon). Typically 0.1 to 10 ohms. =20 You need at least 3 I-V points to get these parameters. More will give a better least-squares fit. =20 Model needs to be accurate over actual operating conditions,=20 including reflections. This should cover from Vcc of reverse voltage to about 1V of forward voltage. Maximum current should not exceed 100 mA, even outside this region. SiQual has addressed diode models in the reflector, with comparison to measurements. =20 Best regards, Lynne=20 =20 Dr. Lynne Green PCB Systems Division Cadence Design Systems, Inc. - -----Original Message----- From: Timothy Coyle [mailto:Timothy.Coyle@nsc.com] Sent: Monday, April 22, 2002 11:51 AM To: ibis-users@eda.org Subject: [IBIS-Users] Input ESD Structures Hello,=20 When I get a SPICE netlist from the design team to do a spi2ibis = translation, the ESD structures have ideal diodes (no resistance) which = leads to kAmps in my=20 power and ground clamp curves. So I put a series resistor of 1-3 Ohms = on the input of the ESD pad (and sometimes the ground node of the ESD = pad) to try to limit=20 the current. While this approach works, my simulated data does not = match up with data taken from the bench. The lab data at one point is = 4.3mA and the simulated=20 data at the same point is 160uA for a ground clamp curve. Changing the = resistor value doesn't give me the right current either. Does anyone = have any=20 comments/suggestions on this approach?=20 Also, I'm wondering what type of affect on my input model the magnitudes = of my power and ground clamp curves have. Does it matter to a simulator = if the ground clamp=20 current is 4.3mA or 160uA? It seems the most important parameter for an = input model is Ccomp. Has anyone done any work on this they would like = to share?=20 Many thanks again to those who respond,=20 Tim=20 - ------_=_NextPart_001_01C1EADB.8733F552 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Hello, = Tim,

The 3 = most=20 significant DC parameters in the diode model:

IS: = "reverse=20 leakage" current, adjusted to give correct forward = current

at low = bias voltage=20 (V<0.4V in silicon). Ranges from around = 1e-16

for = signal diodes=20 to >1e-9=20 for power diodes.

N: = ideality factor,=20 adjusted to give correct forward current at medium

bias = (0.5V to 0.6V=20 in silicon). Usually 1<N<2.

RS: = series=20 resistance, adjusted to give correct forward current at =

high = bias (V>0.7V = in=20 silicon). Typically 0.1 to 10 = ohms.

You need at least 3 I-V points to get these=20 parameters. More will

give a better least-squares = fit.

Model needs to be accurate over actual = operating=20 conditions,

including reflections. This should = cover from Vcc=20 of reverse

voltage to about 1V of forward voltage. = Maximum=20 current should not

exceed 100 mA, even outside this = region. SiQual=20 has addressed

diode models in the = reflector, with comparison to=20 measurements.

Best regards,

Lynne

Dr. Lynne Green

PCB Systems = Division

Cadence Design Systems, = Inc.

-----Original Message-----
From: Timothy Coyle=20 [mailto:Timothy.Coyle@nsc.com]
Sent: Monday, April 22, 2002 = 11:51=20 AM
To: ibis-users@eda.org
Subject: [IBIS-Users] = Input ESD=20 Structures

Hello,=20
When I get a SPICE netlist from = the design=20 team to do a spi2ibis translation, the ESD structures have ideal = diodes (no=20 resistance) which leads to kAmps in my
power and ground clamp curves. So I put a series = resistor of 1-3=20 Ohms on the input of the ESD pad (and sometimes the ground node of the = ESD=20 pad) to try to limit
the = current.=20 While this approach works, my simulated data does not match up = with data=20 taken from the bench. The lab data at one point is 4.3mA and the = simulated
data at the same = point is=20 160uA for a ground clamp curve. Changing the resistor value = doesn't give=20 me the right current either. Does anyone have any =
comments/suggestions on this approach?=20

Also, I'm wondering = what type of=20 affect on my input model the magnitudes of my power and ground clamp = curves=20 have. Does it matter to a simulator if the ground clamp =
current is 4.3mA or 160uA? It seems the = most important=20 parameter for an input model is Ccomp. Has anyone done any work on = this they=20 would like to share?

Many thanks=20 again to those who respond,

Tim

- ------_=_NextPart_001_01C1EADB.8733F552-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Tue, 23 Apr 2002 19:07:22 -0500 From: "Haque, Moshiul" Subject: [IBIS-Users] Model Selector Keyword for Series Pin Mapping Hi All, While creating an IBIS model for series switch, I have noticed that the IBISCHK3.2 gives an error if the model selector keyword is used to define two different models for the same model_name in series pin mapping. IBISCHK3.2 gives an error saying that the model (that is defined in the series pin mapping under model_name column) is not defined. Model selector keyword works fine for other models (input, terminator or 3-state) Any idea what did I do wrong? [Series Pin Mapping] pin_2 model_name function_table_group | 3 2 Q3384A_IO_S 1 [Model Selector] Q3384A_IO_S | Q3384A_IO_S_33 3.3 volt Vcc Q3384A_IO_S_25 2.5 volt Vcc If I use two different series pin mapping with separate model but with same pin mapping will that be an incorrect approach? Example: [Series Pin Mapping] pin_2 model_name function_table_group | 3 2 Q3384A_IO_S_25 1 3 2 Q3384A_IO_S_33 1 Any suggestion would be greatly appreciated. Regards Moshiul Haque Standard Linear and Logic Marketing Texas Instruments Incorporated |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 24 Apr 2002 17:14:20 -0700 From: "Ross, Bob" Subject: Re: [IBIS-Users] Model Selector Keyword for Series Pin Mapping Hello Moshiul: I believe [Model Selector] should work with Series or Series_switch models that would be listed using {Series Pin Mapping]. So it looks like you have uncovered an ibischk3 bug. Could you send me directly a complete (but simplified) test model that demonstrates the Error. I want to check to see if there are any other related issues. Your second case is not correct for the purposes of connecting one switch at a time. Both are connected in parallel. However, if manually comment one line or the other, then it would work for just those pins. Best Regards, Bob Ross Mentor Graphics "Haque, Moshiul" wrote: > > Hi All, > While creating an IBIS model for series switch, I have noticed that the > IBISCHK3.2 gives an error if the model selector keyword is used to define > two different models for the same model_name in series pin mapping. > IBISCHK3.2 gives an error saying that the model (that is defined in the > series pin mapping under model_name column) is not defined. Model selector > keyword works fine for other models (input, terminator or 3-state) Any idea > what did I do wrong? > > [Series Pin Mapping] pin_2 model_name function_table_group > | > 3 2 Q3384A_IO_S 1 > > [Model Selector] Q3384A_IO_S > | > Q3384A_IO_S_33 3.3 volt Vcc > Q3384A_IO_S_25 2.5 volt Vcc > > If I use two different series pin mapping with separate model but with same > pin mapping will that be an incorrect approach? > > Example: > [Series Pin Mapping] pin_2 model_name function_table_group > | > 3 2 Q3384A_IO_S_25 1 > 3 2 Q3384A_IO_S_33 1 > > Any suggestion would be greatly appreciated. > > Regards > Moshiul Haque > Standard Linear and Logic Marketing > Texas Instruments Incorporated > |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 24 Apr 2002 18:10:30 -0700 From: "Ross, Bob" Subject: Re: AW: [IBIS-Users] I-V vs V-T curves Hello Tim: Actually, ibischk3 should work correctly for any set of waveform endpoints based on R_fixture and V_fixture values. The manual calculation of voltage can be done by iteration. You assume a voltage, and then calculate the current needed to supply R_fixture and V_fixture for either the high state hen you add up the currents supplied by the [Pullup] table (plus the [Gnd Clamp] and [Power Clamp] tables for the assumed voltage. If the currents are different, readjust the voltage in the correct direction and repeat. Eventually you should converge on the solution. Then you repeat this process for the low state using the [Pulldown] table and clamps. Bob Ross Mentor Graphics Lenski Eckhard wrote: > > Hello Tim, > > I assume that you are modeling an LVDS-output. > > Normaly ( cmos ) you compare the crossing of the 50Ohmload curves with the > pullup - pulldown curves > > - 50 Ohm to Gnd crossing with pullup curve > - 50 Ohm to Vcc crossing with pulldown curve > > and the rising falling waveforms are measured with a 50 Ohm load to GND and > to VCC. > > For LVDS you have to look for the crossing of your 50 Ohm to 1.2V load-curve > with the pullup and pulldown curves > ( so you havve to use the same loadcurve twice ) > and then there should be no ( or no significant ) mismatch. > > By the way, I think the ibis-checker is always using 50 ohm to gnd and 50 Ohm > to vcc. > > > If you have further questions, please let me know. > > regards > Eckhard Lenski > > > Eckhard Lenski > Siemens AG > ICN WN OP TDC TC3 > 81359 München > Tel: 0049 89 722 27776 > Fax: 0049 89 722 44692 > Email: eckhard.lenski@icn.siemens.de > > -----Ursprüngliche Nachricht----- > Von: Timothy Coyle [mailto:Timothy.Coyle@nsc.com] > Gesendet: Freitag, 19. April 2002 20:24 > An: ibis-users@eda.org > Betreff: [IBIS-Users] I-V vs V-T curves > > Hi, > I am trying to determine where my mismatch end points are coming > from in an IBIS file I am creating. How do I get the end points > from the pullup and pulldown I-V data > so I can compare them to the endpoints in my V-T curves? (load > condition for V-T data is 50 ohms to 1.2V with endpoints 1.0V and > 1.4V) > > Thanks, > Tim |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ Date: Wed, 1 May 2002 11:51:06 -0400 From: Guy deBurgh Subject: [IBIS-Users] DAC 2002 IBIS Summit meeting This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. - ------_=_NextPart_001_01C1F128.1D8F4900 Content-Type: text/plain; charset="iso-8859-1" D A C 2 0 0 2 I B I S S U M M I T M E E T I N G S E C O N D A N N O U N C E M E N T DATE: Thursday, June 13, 2002 TIME: 8:30 AM - 5:00 PM CITY: New Orleans, Louisiana LOCATION: Hilton Hotel, New Orleans Riverside, next to Ernest N. Morial Convention Center where the Design Automation Conference (DAC) is being held. ROOM: To be Announced LUNCH: Free Refreshments and Lunch will be provided. AGENDA: The agenda is being planned. Some possible items are: Presentation of Awards Election of Officers for 2002 - 2003 Connector Specification EMI Modeling IBIS Version 4.0 Review Modeling Experiences, Problems and Solutions The following presentations are tentatively planned (titles may change): "Use of IBIS in Digital Consumer Electronics", Atsuji Ito, Matsushita Electric Industrial Co. (Panasonic) "Semiconductor Modeling", Roy Leventhal, Independent "IBIS Quality Checklist", Barry Katz, SiSoft "Multi-Lingual Modeling Applications", Bob Ross, Mentor Graphics "IBIS Report", Stephen Peters, Intel Corporation We welcome presentations and discussions on IBIS topics. DAC 2001: DAC is scheduled Monday - Friday, June 10 - 14, 2002. The exhibitor portion is open from Monday - Wednesday. For more information on DAC 2002 activities, housing, etc., visit the DAC URL: DAC URL: http://www.dac.com/ CALL FOR PRESENTATIONS: We are also open to technical presentations (usually 30 minutes or less) related to any current IBIS activity and to future IBIS needs. Contact Guy de Burgh regarding your presentation: Presenter: Title: Estimated Time: We are providing an LCD Projector and an Overhead Projector. Please plan to bring foils for backup, if needed. We would like you to provide handouts for the meeting (about 25) and also an electronic copy for archiving. CALL FOR ATTENDEES: Please let Guy de Burgh know if you are planning to attend so we have an estimate on food requirements. CONTACT: Guy de Burgh IBIS Secretary gdeburgh@innoveda.com (805) 988-8250 ext. 6823 - ------_=_NextPart_001_01C1F128.1D8F4900 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable DAC 2002 IBIS Summit meeting

&nb= sp; D A C 2 0 0 2 I B I S S U M M I = T M E E T I N G
&nb= sp; S E C O = N D A N N O U N C E M E N T

DATE: Thursday, June = 13, 2002
TIME: 8:30 AM - 5:00 = PM

CITY: New Orleans, = Louisiana

LOCATION: Hilton Hotel, New Orleans Riverside, = next to Ernest N. Morial

= Convention Center where the Design Automation Conference
(DAC)
= is being held.

ROOM: To be = Announced

LUNCH: Free Refreshments and = Lunch will be provided.

AGENDA: The agenda is being = planned. Some possible items are:

&nb= sp; Presentation of Awards
&nb= sp; Election of Officers for 2002 - 2003

          &nb= sp; Connector Specification
          &nb= sp; EMI Modeling
          &nb= sp; IBIS Version 4.0 Review
          &nb= sp; Modeling Experiences, Problems and Solutions

= The following presentations are tentatively planned (titles
may
= change):

          &nb= sp; "Use of IBIS in Digital Consumer Electronics", = Atsuji Ito,
          &nb= sp;     Matsushita Electric Industrial Co. = (Panasonic)
          &nb= sp; "Semiconductor Modeling", Roy Leventhal, = Independent
          &nb= sp; "IBIS Quality Checklist", Barry Katz, SiSoft
          &nb= sp; "Multi-Lingual Modeling Applications", Bob Ross, = Mentor
Graphics
          &nb= sp; "IBIS Report", Stephen Peters, Intel = Corporation

= We welcome presentations and discussions on IBIS topics.

DAC 2001: DAC is scheduled Monday - Friday, = June 10 - 14, 2002.
           = The exhibitor portion is open from Monday - Wednesday.
           = For more information on DAC 2002 activities, housing, etc.,
           = visit the DAC URL:

DAC URL: http://www.dac.com/

CALL FOR PRESENTATIONS:

           = We are also open to technical presentations (usually 30
minutes
           = or less) related to any current IBIS activity and to future
IBIS
           = needs.

= Contact Guy de Burgh regarding your presentation:

          &nb= sp;   Presenter:
          &nb= sp;   Title:
          &nb= sp;   Estimated Time:

= We are providing an LCD Projector and an Overhead Projector.
= Please plan to bring foils for backup, if needed.

= We would like you to provide handouts for the meeting (about
25)
= and also an electronic copy for archiving.

CALL FOR ATTENDEES:

= Please let Guy de Burgh know if you are planning to attend so

= we have an estimate on food requirements.

CONTACT:   Guy de Burgh
           = IBIS Secretary
           = gdeburgh@innoveda.com
           = (805) 988-8250 ext. 6823

- ------_=_NextPart_001_01C1F128.1D8F4900-- |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just the appropriate command message(s) in the body: | | help | subscribe ibis | subscribe ibis-users | unsubscribe ibis | unsubscribe ibis-users | |or email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993 ------------------------------ End of ibis-users V1 #5 ***********************