[ibis-macro] Re: Lets go all the way!

  • From: "Walter Katz" <wkatz@xxxxxxxxxx>
  • To: <Arpad_Muranyi@xxxxxxxxxx>, "'IBIS-ATM'" <ibis-macro@xxxxxxxxxxxxx>
  • Date: Mon, 27 Aug 2012 13:05:29 -0400 (EDT)

Arpad,

 

That is exactly what an EMD contains. 

 

Walter

 

From: ibis-macro-bounce@xxxxxxxxxxxxx
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad
Sent: Monday, August 27, 2012 12:48 PM
To: 'IBIS-ATM'
Subject: [ibis-macro] Re: Lets go all the way!

 

Walter,

 

What I am trying to stay away from are things like this:

 

"The (Pins . ) in the .ibsx file are really Pads."

 

Let's do things the right way and call things by their real

name...  What I have in mind is this:

 

The IBIS file starts with the [Component] keyword.  What makes

up a component, i.e. what does it consist of?  Well, it has

pins (or balls), package, at least one die (could be more).

Then on the die we have pads (bumps) and we might have on-die

interconnects between the pads and buffer terminals.

 

Currently, IBIS starts out correctly with the [Pin] and package

keywords in the [Component] but we forgot to declare and name

(instantiate) the die, and that's where things are starting to

fall apart.  I would like to fix that but listing out all the

elements that make up a component, including the die and its

on-die interconnects, and do all this using the correct hierarchy

and terminology.

 

Thanks,

 

Arpad

==================================================================

 

From: Walter Katz [mailto:wkatz@xxxxxxxxxx] 
Sent: Monday, August 27, 2012 6:58 AM
To: Muranyi, Arpad; 'IBIS-ATM'
Subject: RE: [ibis-macro] Re: Lets go all the way!

 

Arpad,

 

Note that in this IBISx approach, the Model is not associated in the
package .emd file. The package .emd file references a die .ibsx file. The
(Pins . ) in the .ibsx file are really Pads. These Pins (Pads) do
reference the buffer model name. I do think that this instantiate [Models]
the right way by associating [Models] with the die pads instead of the
package pins.

 

Are you suggesting that in the .ibsx file we have a list of Pins (pads),
and a separate list of [Models]? Can you describe any existing silicon
that would require this?

 

Walter

 

From: ibis-macro-bounce@xxxxxxxxxxxxx
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad
Sent: Monday, August 27, 2012 12:07 AM
To: IBIS-ATM
Subject: [ibis-macro] Re: Lets go all the way!

 

Walter,

 

I think you may have misunderstood my comment last Friday,

because I don't remember saying what you write below.  I

don't even see myself saying it, because I don't think there

is really a "problem that legacy IBIS combines both package and die

models in .ibs files", because the most accurate package modeling

syntax that is available in IBIS currently allows the [Define

Package Model] keyword (and its content) to be either in the

.ibs or the (separate) .pkg file.  Either way, I am really

not very concerned about having things in one or multiple

files.

 

My comment last Friday was about the mechanism by which the

IBIS specification defines and instantiates [Model]s using

the [Pin] keyword.  This was OK in the days when the number

of pins were the same as pads and the package had a one-to-one

pin to pad path.  But now that we are talking about arbitrary

pin and pad relations, and now that we are talking about

adding to this an also arbitrary pad to buffer terminal on-die

interconnect modeling capability, we can no longer rely on

defining and instantiating [Model]s using the pin names.  I

made the suggestion on Friday, that if we "overhaul" IBIS

with significant changes as you suggested in your presentation,

we should also consider this and instantiate [Model]s the

right way.  Doing this the right way might make the rest of

the package and on-die interconnect syntax cleaner.

 

Thanks,

 

Arpad

================================================================

 

 

From: ibis-macro-bounce@xxxxxxxxxxxxx
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Walter Katz
Sent: Sunday, August 26, 2012 2:03 PM
To: IBIS-ATM
Subject: [ibis-macro] Lets go all the way!

 

All,

 

In the Friday Open Forum meeting Arpad raised a question that reflects the
problem that legacy IBIS combines both package and die models in .ibs
files. I believe the answer to this question is to split up "components"
into a package EMD file and a die IBISx file.

 

The enclosed presentation illustrates this using the example legacy IBIS
file in my last presentation.

 

Walter

 

Walter Katz

wkatz@xxxxxxxxxx

Phone 303.449-2308

Mobile 303.335-6156

 

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