Subject: IBIS BIRD60 - Electrical Board Description Diagrams

From: Bob Ross <[email-masked]>
Date: Wed, 04 Aug 1999 18:35:31 -0700

To IBIS Committee:

BIRD60 documents the intended diagrams to be included in IBIS Version 3.2
in response to an editorial letter ballot comment on SP-4557 regarding
the Electrical Board Description examples.

Please review these for discussion at the Friday August 6, 1999 IBIS Meeting.

Bob Ross
Mentor Graphics

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BIRD ID#:       60
ISSUE TITLE:    Electrical Board Description Diagrams
REQUESTER:      Bob Ross, Mentor Graphics
DATE SUBMITTED: August 4, 1999
DATE ACCEPTED BY IBIS OPEN FORUM: Pending

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STATEMENT OF THE ISSUE:

The need to illustrate the Electrical Board Description examples was raised
in letter ballot responses to SP-4557.

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STATEMENT OF THE RESOLVED SPECIFICATIONS:

The [Path Description] keyword example is presented with added diagrams.  In
the second example U23.15 is changed to U23.16.

Replace the existing example section with the revised example below:

|-----------------------------------------------------------------------------
|
|
|  An Example Path For a SIMM Module:
|
[Path Description] CAS_2
Pin J25
Len = 0.5 L=8.35n C=3.34p R=0.01 /
Node u21.15
Len = 0.5 L=8.35n C=3.34p R=0.01 /
Node u22.15
Len = 0.5 L=8.35n C=3.34p R=0.01 /
Node u23.15
|
|        +-------------------------------------------------------------
|        |
|        |         _______         _______         _______
|   J25 <---------O_______O---+---O_______O---+---O_______O---+
|        |         Len=0.5    |    Len=0.5    |    Len=0.5    |
|        |                    |               |               |           
|        |                 +--+--+         +--+--+         +--+--+
|        |                 |Pin15|         |Pin15|         |Pin15|
|        |                 |     |         |     |         |     |
|        |                 | U21 |         | U22 |         | U23 |
|        |                 |     |         |     |         |     |
|        |
|
|  A Description Using The Fork and Endfork Subparameters:
|
[Path Description] PassThru1
Pin B5
Len = 0   L=2.0n /
Len = 2.1 L=6.0n C=2.0p /
 Fork
 Len = 1.0 L = 1.0n C= 2.0p /
 Node u23.16
 Endfork
Len = 1.0 L = 6.0n C=2.0p /
Pin A5
|
|        +-------------------------------------------------------------
|        |
|        |                ______________ 
|    A5 <----------------O______________O-------------+
|        |                   Len=1.0                  |
|        |                                            |
|        |           _____________________________    |
|    B5 <---@@@@@---O_____________________________O---+
|        |  2 nH                Len=2.1               |
|        |                                            |
|        |                          ______________    |
|        |                     +---O______________O---+
|        |                     |       Len=1.0
|        |                     |
|        |                  +--+--+
|        |                  |Pin16|
|        |                  |     |
|        |                  | U23 |
|        |                  |     |
|        |           
|
|  A Description Including a Discrete Series Element:
|
[Path Description] sig1
Pin B27
Len = 0  L=1.6n /
Len = 1.5 L=6.0n C=2.0p /
Node R2.1
Node R2.2
Len = 0.25 L=6.0n C=2.0p /
Node U25.6
|
|        +-------------------------------------------------------------
|        |
|        |                                 +----------+
|        |           __________________    |Pin    Pin|    ___
|   B27 <---@@@@@---O__________________O---+ 1      2 +---O___O---+
|        | 1.6 nH         Len=1.5          |    R2    |  Len=0.25 |
|        |                                 +----------+           |           
|        |                                                     +--+--+ 
|        |                                                     |Pin 6|
|        |                                                     |     |
|        |                                                     | U25 |
|        |                                                     |     |
|        |
|
|=============================================================================

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ANALYSIS PATH/DATA THAT LED TO SPECIFICATION:

Diagrams are added to clarify meanings the topologies that are represented
in the examples associated with the [Path Description] keyword of the EBD.
A duplicate pin number is corrected that could lead to a misinterpretation.
Two different paths were connected to U23.15. The second path was changed
so that it connected to U23.16.  If this were not corrected the set of
examples might imply a contination of the path, if they were to have been
for the same board.

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ANY OTHER BACKGROUND INFORMATION:

This is in response a letter ballot comment submitted in June, 1999 on
SP-4557 for EIA ratification of Version 3.2 by Cisco Systems:

Cisco Systems: 4
Editorial
Reference: Page 69
Suggested Change: Need a diagram clarification of parameters used.

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