[IBIS-Users] Warning message for MISMATCH

From: lau yy <tok47_at_.....>
Date: Thu Apr 06 2006 - 03:23:04 PDT
Hi ALL,
 
Below I attach a model for an IO pin. The model pass with warning. I show 1 of the warning message as below:
 
WARNING - Model IO: The [Falling Waveform]
      with [R_fixture]=50 Ohms and [V_fixture_max]=3.6V
      has MAX column DC endpoints of  1.98V and  3.53v, but
      an equivalent load applied to the model's I-V tables yields
      different voltages ( 1.94V and  3.39V),
      a difference of  2.36% and  3.96%, respectively.
I study the rising and falling datas, can see that the pin is already stable but is just the voltage level can fall to 0 or reach VCC. Is this a design issue or modeling issue? I belive that is the pullup and pulldown transistor not strong enough. Am I right?
 
PLease comment.
 
Thanks
 
rdgs
yylau
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Received on Thu Apr 6 03:23:16 2006

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