Subject: Bird 14 comments

From: Stephen Peters <[email-masked]>
Date: Thu, 12 May 1994 08:57:20 -0700

Hello Fellow IBISans --

     I've been following the comments going back and forth on Bird 14,
and somthing Bob Ross said in this last reply struck me as fundemental
to how we wish to 'grow' this specification.  Bob's comment was:

"....So if Cref is really useful then I would not object to having it in.  At
this time, however, I do not see Cref or any other proposed parameter as
being required.  Any parameter that is not required cannot be relied upon to
exist by simulator vendors.  So at worst the additional parameters may be
for information only....."

     As I see it, bird 14 takes IBIS beyond simply providing basic 
information for signal integry analysis into providing 'data book' 
information; enough for full board timing simulation.  If this type
                                   ^^^^^^
of information is not *required* or directly used by the simulator to
produce waveforms, then we have two distinct types of models -- one for 
signal integrey analysis and a more complex one that helps in full board 
timing simulations.  Perhaps this is a good place to make the break between
Level 1 models and Level 2 models.  Comments, anyone?

---

From: [email-masked] (C. Kumar)
Date: Thu, 12 May 94 12:43:17 -0400

> Level 1 models and Level 2 models.  Comments, anyone?

This goes back to my suggestion few weeks ago. I suggested that it is natural
to have timing information under IBIS. Timing information can follow a
a format similar to the one proposed for package models. 

- Kumar