[IBIS] Re: Subtracting "Lead-in" Offset from V-t curves

  Hi David,

      If you refer to time offset then you must substract the same offset
amount to all of the rising/falling waveform tables (in order to keep the
duty cycle), but be careful with this action because the cause of this
offset in some ibis simulators (hspice for example) is the input you put to
the buffer (b element in hspice)implemented with ibis model is limited to
switch between 0 and 1, then the Vinl Vinh thresholds are different between
you transistor-level buffer and your buffer ibis.

 Regards,

        Ramiro Lecona

David Mahashin escribió:

> Hi,
>
> I have a question concerning the offset on V-t curves. I realize that most
> simulators (e.g. Hyperlynx) have the option of automatically stripping the
> "lead-in" offset.
>
> However, if I do want to subtract the offset manually, is it necessary to
> subtract the same offset amount to all of the rising/falling waveform
> tables?
>
> What is the effect of subtracting different offset amounts such that all the
> waveforms rise/fall at the same point in time? Will this incorrectly model
> the input to output delay of the buffer?
>
> Thanks,
>
> David
>
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Received on Wed Dec 22 10:23:00 2004