Clarifications on IBIS standard

Clarifications on IBIS standard

We are in the process of making IBIS models and there were a few items
in the standard and in the discussions which were not clear to us. I hope
somebody can clear these issues.

1. When is the Golden Parser for version 2.0 likely to be ready ?

2. It is rightly pointed out that the pulldown and pullup
characteristic for tristate outputs may be non-monotonic. The standard
says that this can happen in at most one place. The i-v characteristic
may then locally have a negative resistance. Will this not pose a
problem to simulators ?

3. During a transition, it is not clear whether the pullup or pulldown
characteristics should be used by a simulator. This is not a problem
for making the IBIS models, but only for using them in a simulator.

4. Is there a provision for specifying a pad or die resistance i.e
R_comp in addition to C_comp?

5. The standard does not explicity specify the nature of the input
ramp in obtaining ramp rates. What should be the input rise time as
well as the high and low values of the input pulse?

Perhaps many of these issues have been thrashed out at different
forums. I would be greatly obliged if somebody would educate me on
this.

        Raj Raghuram
        National Semiconductor
        2900 Semiconductor Drive
        Mail Stop D3-677
        Santa Clara, CA-95052
        email: raghu@berlioz.nsc.com
        Phone: (408) 721-6220 (O)
        Phone: (408) 252-1285 (H)
Received on Thu Feb 2 10:38:05 1995