Buffer Issue Resolution Document (BIRD)
BIRD ID#: 32
ISSUE TITLE: Additional Enhancement To The Package Model (.pkg file) Specification
REQUESTER: C. Kumar
DATE SUBMITTED: Dec 14, 1995 (Actual Submission Jan. 11, 1996)
DATE ACCEPTED BY IBIS OPEN FORUM: Rejected May 30, 1997
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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.

 SubParams: 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 3line 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
 SubParams: 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
1.5e11 0.2e13
[ROW] 2
0.2e13 1.5e11
[END CMATRIX]
[END MATRIX]
[MATRIX] 3line
.....
....
...
[END MATRIX]
...
..
[END MATRIX DATA]