Re: Proposed Golden IBIS Parser checks

Hi group,

At 11:43 AM 11/4/98 -0700, D. C. Sessions wrote:
>Matthew Flora wrote:
>> Proposed enhancements:
>> 2) Generate at least a warning if the Pullup or Pulldown V/I table
indicates
>> that current is always flowing in one direction. In other words, the
V/I
>> table does not have an entry with zero current or, by interpolation, the
>> current is never zero in the range of the voltages listed.
>> I think a warning should be generated even if the current would be zero
>> when extrapolated to a voltage beyond those listed in the table
because I
>> believe that V/I tables should be complete and should not force a
simulator
>> to guess values and, to me, extrapolation beyond the voltages listed
in the
>> table is a guess.
>If I understand you correctly, you would insist that the tables
>go at least to the zero-current intercept point. Thus, for an
>1.5v device with a weak pullup to 5.0v you'd have the tables go
>at least to 5v so as to catch the intercept?
Matt asked for a warning. Not an error. Just a way to say are you really
sure this is what you wanted. The warning could even say this condition
may be valid
for some classes of devices.

>> 3) For non-ECL models, shouldn't the zero current voltage for the Typ, Min,
>> and Max columns in the Pullup or Pulldown V/I tables be the same (say
>> within a microvolt)? I suggest that a warning be generated if they are
>> not.
>Lots of technologies have zero-current intercepts inside of their
>rails. ECL is only one of them; perhaps you've heard of TTL?
I think Matt is asking that the zero current intercept be the same for
typ,min,max not that it be 0.

>> 4) Related to a topic recently discussed on the reflector, I suggest
that an
>> error be generated if a differential pin (a pin referenced in the
>> [Diff pin] section) is connected to one of the reserved models
(POWER, GND,
>> or NC).
>This would barf on RS-423
Good point.
Received on Wed Nov 4 11:29:45 1998