Re: True or False?

Arpad,

Since you must have the [Series Map] to connect IN to OUT and therefore
must have terminators on those pins to stay "legal" for the time being,
I urge for you to leave out the [Diff Pin] relationship and rely on
another device within the board to associate the nets since you can't
legally put an actual sensing receiver at the series pin locations
anyway.

As a temporary solution, this method would result in the proper
connectivity for our customers...any other vendors care to comment?

If you want to leave it in that is your choice as I must surrender that
your model may actually be legal--perhaps due to an oversight in the
[Diff Pin] specification (noticed I used the word "may"!!). We will
instruct our customers to delete the [Diff Pin] lines until we are able
to support it with a patch (yuck!).

Viewlogic will endorse a proposed BIRD allowing other types of models on
the series pin nodes.

Chris

P.S. I will be out of the office all next week so am defenseless to
your reply :) !!

Muranyi, Arpad wrote:
>
> Chris,
>
> I don't know what it feels like to be an attorney, because I have never been
>
> one. I wonder about the same question...
>
> Regarding A) The device has a differential input, so I DO HAVE TO use the
> [Diff Pin] keyword. The die has a direct connection between
> the
> pads which do the loopback, so I must have a way to describe
> the
> series properties of those connections. The only model type
> that
> is allowed in the IBIS spec with the series models is the
> "non-sensing" Terminator model type. Do you have a suggestion
> for
> how to model this other than the way I did it? I am willing to
> make changes if it makes sense...
>
> Regarding B) I have to make a model now, since the customer wants to use it
> immediately. Even though I would prefer this, I can't wait for
> a
> new IBIS spec version.
>
> I don't see why my model is "debatebly" legal because nothing I did in it is
>
> illegal according to the spec. The model makes sense if you think about
> what it
> describes and not about what the comments in the spec say regarding what the
>
> Terminator models could be used for.
>
> So we have a choice of fixing the spec, make legal (but "senseless"?
> models), or
> not have any models. Which one would you choose when the customer wants to
> simulate and is pounding on the door for models?
>
> Remember, this is an existing device and we should both be interested in
> finding
> a way to model it.
>
> Arpad
> ============================================================================
Received on Fri Oct 9 18:33:42 1998