Re: [IBIS-Users] warning with ibischk3.2

Hello lynne,

  I am not given any rising and falling wavform in my cell, I just give
ramp information(because it's a differential cell).Can you please also
give me some doc that help me to extract rising and falling waveform
from some differential cell that have small swing like 300mv .
  I also check that IBISCHK4 report same problem.
  I am not sure that my production team is using which resistence but by
default I use 1-meg resistence.
  With test load i think we make RC and give some delay(correct me if I
am wrong). Can you please also told me exect use of test load and on
which condition it depend, speciallyt Vref and Rref.

With best regards
Akhilesh
lgreen wrote:

>Hello, Akhilesh,
>
>Do both the rising and falling SPICE waveforms pass through 1V with this
>load? If this is a differential buffer, remember that IBIS only checks one
>I/O pad at a time.
>
>I would recommend trying ibishck4 to see if the problem still occurs. You
>could also submit your model to the IBIS model review committee (please
>include "IBIS Model Review Committee" in the subject).
>
>- Lynne
>
>PS: Does your production group really use 1-Meg as their timing test load?
>Many companies use loads around 50-150 Ohms.
>
>
>
>"IBIS training when you need it, where you need it."
>
>Dr. Lynne Green
>Green Streak Programs
>http://www.greenstreakprograms.com
>lgreen22@mindspring.com
>
>
>-----Original Message-----
>From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org] On Behalf
>Of Akhilesh CHANDRA
>Sent: Friday, November 05, 2004 5:16 AM
>To: ibis-users@eda.org; ibis@eda.org
>Cc: Akhilesh CHANDRA
>Subject: [IBIS-Users] warning with ibischk3.2
>
>Hello,
>
> I am geting following warning in one of my differential cell when I
>run ibischk3.2. Can anybody help me to find out how it come and where it
>effect because I run my cell lebel simulation with this model and result
>are near to spice.
>
>WARNING - Model 'LVPECLDRV_3V3': TYP VI curves cannot drive through Vmeas=1V
> given load Rref=1e+06 Ohms to Vref=0.9V
>WARNING - Model 'LVPECLDRV_3V3': MIN VI curves cannot drive through Vmeas=1V
> given load Rref=1e+06 Ohms to Vref=0.9V
>WARNING - Model 'LVPECLDRV_3V3': MAX VI curves cannot drive through Vmeas=1V
> given load Rref=1e+06 Ohms to Vref=0.9Vak, Michael wrote:
>
>
>
>>Regards
>>
>>
>>
>Akhilesh
>
>
>
>>
>>
>>
>>
>
>
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Received on Tue Nov 9 01:16:56 2004