All,
Rather than discussing the possible IBIS solutions for package models, I
would like to describe the physics of the problem, and then ask some
questions of what part of the physics need to be implemented.
I would like to frame these questions with an example:
Package
150 VDD Pins
150 VSS Pins
100 Single Ended Channel Pins
Die Bump Pads
200 VDD Bump Pads
200 VSS Bump Pads
100 Single Ended Channel Bump Pads
Die Buffer Pads
100 VDD Buffer Pads
100 VSS Buffer Pads
100 Single Ended Channel Buffer Pads
Complete Package Model (describes the full physics of the package
interconnect)
150 VDD Pins
150 VSS Pins
100 Single Ended Channel Pins
200 VDD Bump Pads
200 VSS Bump Pads
100 Single Ended Channel Bump Pads
900 total ports
Complete On-Die Model (describes the full physics of the die interconnect)
200 VDD Bump Pads
200 VSS Bump Pads
100 Single Ended Channel Bump Pads
100 VDD Buffer Pads
100 VSS Buffer Pads
100 Single Ended Channel Buffer Pads
A Full Simulation will consist of
Board and all of the stuff on the Board
1 Package model instance
1 on-die model instance
100 IBIS buffers
Connections that need to be rectified
400 connections between Board and Package Model
500 connections between Package Model and On-Die Model
300 connections between On-Die Model and 100 Buffer Models
Questions to IC Vendors:
Is this setup is a completer representation of the problem?
Is it practical to produce the Package Model and On-Die Model in this
level of detail?
Do you want/need to use a subset of the on-die VDD and VSS Bump Pads in
your On-Die Model?
Do you want to be able to represent the VDD and VSS Bump Pads as two
nodes?
Do you already include the interconnect between the Channel Bump Pads and
Channel Buffer Pads in your Buffer Model?
Do you need interconnect between VDD and VSS Bump Pads and VDD and VSS
Buffer Pads, or is it sufficient to "tie" each VDD and VSS Buffer Pad to
specific VDD and VSS Bump Pads.
Do you want to be able to distribute Package and On-Die Models for slices
(subsets) of the 100 Channels?
Do you want to be able to distribute multiple Package and On-Die Models
with different combinations of the choices above?
Walter
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Received on Fri Jul 20 13:27:32 2012
This archive was generated by hypermail 2.1.8 : Fri Jul 20 2012 - 13:27:44 PDT