Subject: new bird for enahnced packaging

From: [email-masked] (C. Kumar)
Date: Tue, 9 Jan 96 10:49:37 -0500

Hello Fellow IBISians:

Here is BIrd on enhancemnet to package modelling. This builds on Stephen's BIRD 28. The major benefits of the bird are outlines in the first paragraph.

Regards
C. Kumar
Cadence Design Systems

                 Buffer Issue Resolution Document  (BIRD)
BIRD ID#:        32
ISSUE TITLE:     Additional Enhancement To The Package Model (.pak file) Specification
REQUESTER:       C. Kumar
DATE SUBMITTED:  Dec 14, 1995
DATE ACCEPTED BY IBIS OPEN FORUM:  Pending

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STATEMENT OF THE ISSUE:  BIRD 28.3 enhancement to package model addresses "large"packages which go beyond the realm of lumped circuit modelling. It also partly addresses etch to etch coupling. However it imposes restrictions on the number of sections and the requirement that only adjacent etches can be coupled. The current bird removes such restrictions. The key benefits of this bird are

1. Etches can have arbitrary amount of sections
2. The coupling is not restricted to adjacent etches
3. The coupling matrice are referenced by name . This achieves highly compact descriptions of coupling. It is well known that layouts are characterized by cross sections which occur repeatedly and one description per cross section should be sufficient.
4. A new matrix data section is proposed which contains the data for the matrices. This section differs from the package matrix sections in important ways. a). The matrix is referred to by a name and thus multiple instance of the matrix can be specified by just one description. b). The matrix section is ideally suited for trace cross section description. These cross sections are usually a SET of Resitance, Inductance, Conductance and Capacitances (RLGC matrices ) and the matrix section can optionally contain all of them.

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STATEMENT OF THE RESOLVED SPECIFICATIONS: Following are the specific changes. These are changes over and above that of BIRD 28.3

1. The keyword [Number of Sections] is not required since variable number of 
   sections for each pin is allowed

2. The Matrix key word is replaced by Matrix Name parameter and Matrix pin order parameter.

3. A new kwy words [MATRIX DATA] and [END MATRIX DATA] are introduced. This section should contain data for the matrices referenced in the [Pin Number] key word

4. The current [Pin Numbers] keyword (post BIRD 28.3) is modified
|============================================================================= 
|    Keyword: [Pin Numbers]
|   Required: Yes
|Description: Tells the parser the set of names that are used for the package
|             pins and also defines pin ordering.  Each pin number should 
|             start as the first character in a new line.
|
| Sub-Params: Len, L, R, C, Matrix, MxPinOrder
|
| The Matrix now just identified the name of the matrix and MxPinOrder shows how
| the rows of the matrix is mapped to etches emanating from the pins
|
|             In the example below the first section is a lumped inductor,
|             the second section is described using a 3-line matrix, and 
|             the third
|             section is modeled using distributed elements.  Pin A3 shows
|             an example of sections with no data.  Pin A3 also shows a 
|             2line matrix section coupled to A5! Pins A4 and A5 illustrate
|             how a section description can be broken across multiple lines
|             and how each section description is delimited by the slash.
|-----------------------------------------------------------------------------
[Pin Number]
A1   Len = 0 L=1.2n / Len = 1.3 Matrix=3line MxPinOrder=(A1 A2 A3) / 
     Len=0.47 L=8.35n C=3.34p R=0.01 /
A2   Len = 0 L=1.4n / Len = 1.2 Matrix=3line MxPinOrder=(A1 A2 A3)/ 
     Len=0.47 L=6.21n C=3.34p R=0.01 /
A3   Len = 0        / Len = 1.1 Matrix=3line MxPinOrder=(A1 A2 A3)  / 
 
     Len = 0  Matrix=2line MxPinOrder=(A3 A5)                       /
A4   Len = 0 L=1.2n / Len = 1.0 L=2nH / Len=0.47 L=8.35n 
     C=3.34p R=0.01/
A5   Len = 0 L=1.2n /  
     Len=1.2 Matrix=2line MxPinOrder=(A3 A5) / 
     Len=0.47 L= 8.35n C=3.34p R=0.01 /
|
|    Note that the actual length for each section is reported, even for
|    those sections that use the Matrix subparameter.
|
3. A new section [MATRIX DATA] is introduced
|
|=============================================================================
|    Keywords: [MATRIX DATA] [END MATRIX DATA]
|    Required: Yes , if the [Pin Number] contains references to matrices
|
3. The key word Matrix is modified
|=============================================================================
|    Keyword: [Matrix] [END MATRIX]
|   Required: Yes if used in the [Pin Numbers] section
|Description: Identifies the per unit length RLGC matrices of the cross section
| Sub-Params: SIZE, TYPE, RMatrix, LMatrix, GMatrix, CMatrix, ROW, 
|             [END RMATRIX], [UNIT]
|             [END LMATRIX] [END CMATRIX] [END GMATRIX]
|
|
|  The following example shows 2line matrix 
|   The end sections explicitly identifies each of the sections
|   
|   [UNIT] is a sub parameter which specifies the per length unit
|   Sub parameter like [UNIT] cna be specified at the [MATRIX] level
|   and/or specified at the lower levels like [RMATRIX] etc. The 
|   specification at the lowest level is the one which will be used.
|   For example if the unit is specified both at the [MATRIX] level and
|   at teh [RMATRIX] level, the specification at the [RMATRIX] will be the
|   one which will be used for the Rmatrices. If [UNIT] is not specified
|   a default of per meter will be assumed
|
|   If [TYPE} is not specified a default of Full_matrix will be assumed
|
|============================================================================

[MATRIX DATA]

[MATRIX] 2line
{SIZE] 2
[UNIT] Meter

[RMATRIX]
[UNIT] Meter 
[TYPE] Full_Matrix
[ROW] 1
3.29 0
[ROW] 2
0 3.29
[END RMATRIX]

| Note : unit and type for CMATRIX is defaulted
[CMATRIX]
[ROW] 1
1.5e-11 -0.2e-13
[ROW] 2
-0.2e-13 1.5e-11 
[END CMATRIX]

[END MATRIX]

[MATRIX] 3line
.....
....
...
[END MATRIX]

...
..

[END MATRIX DATA]

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