[ibis-macro] Re: [ibis-interconn] Re: We need to define terms System, Component, Connected, Connection, Module, .ibs Package and Die, .ibs Bare Die

  • From: "Walter Katz" <wkatz@xxxxxxxxxx>
  • To: "'IBIS-Interconnect'" <ibis-interconn@xxxxxxxxxxxxx>
  • Date: Fri, 8 Feb 2013 15:43:13 -0500 (EST)



First definition is for "Connected" fixed below. A connection may have a
blocking cap. At DC it is high impedance, but will be low Impedance at
Nyquist. Of course "Low" or "Small" impedance is not very precise. A long
connect with a blocking cap could have in insertion loss of ~30dB at


A bare die is mounted in a Module. The wire bond is in the Module
interconnect and is accounted for in the Module interconnect module,
similar for flip mounted.




From: ibis-interconn-bounce@xxxxxxxxxxxxx
[mailto:ibis-interconn-bounce@xxxxxxxxxxxxx] On Behalf Of Lynne C. Green
Sent: Friday, February 08, 2013 3:21 PM
To: IBIS-Interconnect
Subject: [ibis-interconn] Re: We need to define terms System, Component,
Connected, Connection, Module, .ibs Package and Die, .ibs Bare Die



My usual nits, from a "newbie" viewpoint.

Where will the interconnect between bare die and package be accounted for?
It is not in the IBIS [Model] or the Component [Pin] list.  And apparently
not in "Interconnect Subckt".  Presently accounted for in [Package Model].

Quibbles on zero ohm impedance. 
a) bare die, where wire bond is the package.  Package impedance
approximately 1nH, varies with wire bond length. 
b) bare die, flip mounted (on module or another die).  Package impedance
approximately 0.1nH. 
Neither case is negligible at 100Gb/sec (alpha prototyping now). 

Having two definitions of "Connection" is confusing me.  In simulation, a
"node" means a dead short - one node number, negligible impedance, etc.
While I can see the first definition, the second one is confusing me.

Other than those nits, this is definitely clarifying things for me.


On 2/8/2013 8:00 AM, Walter Katz wrote:



There has been two much confusion on what EMD is and a comprehensive .ibs
package and on-die interconnect solutions, so I propose the following
definitions to clarify future discussions.



A system consists of multiple components that have electrical connections
between them.


A basic building block of a System. A component can be a backplane, PCB,
Connector, Cable, DIMM component, Multi Chip Module, Interposer, package,
a packaged die, a bare die, and other things that have not been invented


Two electrical nodes in a system are connected if the Insertion Loss
between the two points at Nyquist is "Small". 


A connections consists of a list of electrical nodes that are all
connected to each other.


A Module is a Component that has Pins that connect to other system
components, and contains Components and Connections between these
Components, and between these Components and the Module's Pins.


One proposed solution that describes Interconnect Subckts between the
Module Pins and/or Module Components Pins

IBIS Component

Represented by a .ibs file, contains one, and only one die, [Models],
package interconnect between the [Component] [Pins] and Die Pads, on-die
interconnect between the die pads and the [Model].

Bare Die IBIS Component

A special case IBIS Component that represents a physical Die that is
mounted directly in a Module. An example of this is a multi-chip module
(MCM) that contains two are more die that are mounted and wire bonded
directly on the MCM surface. The [Pin] and on-die pad are at the same
location, and the Package model should be treated as a zero ohm resistor.

Interconnect Subckt

An IBIS-ISS subckt or a Touchstone File that has ports that as described
below. The ports may or may not be connected to all of the other ports.



Component Pins

IBIS Package


Die Pads

On-Die Interconnect

Die Pads

[Model] ports


Note that a Module (and therefore EMD) never has connections to [Model]!!!







Walter Katz


Phone 303.449-2308

Mobile 303.335-6156



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