[ibis-interconn] Re: Package Precedence In IBIS 6.0
- From: "Muranyi, Arpad" <Arpad_Muranyi@xxxxxxxxxx>
- To: IBIS-Interconnect <ibis-interconn@xxxxxxxxxxxxx>
- Date: Tue, 20 Jan 2015 21:55:48 +0000
Walter,
Regarding "The only precedence rule I can find is between [Component]/[Package]
and [Component]/[Pin]",
while the spec doesn't state whether the [Package Model]+[Define Package Model]
keyword should automatically override the [Package] or [Pin] keyword based
package models or whether the EDA tool should give the user an option to select,
it does say that "if more than the default RLC package model is desired, use the
[Define Package Model]" (pg. 137), so there is a precedence rule in the spec on
that...
Thanks,
Arpad
==================================================================================
From: ibis-interconn-bounce@xxxxxxxxxxxxx
[mailto:ibis-interconn-bounce@xxxxxxxxxxxxx] On Behalf Of Walter Katz
Sent: Wednesday, November 05, 2014 10:49 AM
To: IBIS-Interconnect
Subject: [ibis-interconn] Package Precedence In IBIS 6.0
All,
In summary there are several methods to define package models:
1. [Component]/[Package] RLC Lumped
2. [Component]/[Pin] RLC Lumped
3. [Package Model] Path/Fork
4. [Alternate Package Models] Path/Fork
5. [Define Package Model] RLC Matrix
6. [Interconnect Model Selector] IBIS-ISS
The only precedence rule I can find is between [Component]/[Package] and
[Component]/[Pin]
I recommend the following:
1. [Component]/[Pin] takes precedence over [Component]/[Package]
2. If the IBIS File/Component has one or more of the following, the EDA
tool may choose to use any of the following package modeling methods or the RLC
Lumped from [Component]/[Pin]/[Package]
Walter
Page 20
Other Notes: If RLC parameters are available for individual pins, they can be
listed in columns
4-6 under keyword [Pin]. The values listed in the [Pin] description section
override the default values defined here. Use the [Package Model] keyword for
more complex package descriptions.
If defined, the [Package Model] data overrides the values in the [Package]
keyword. Regardless, the data listed under the [Package] keyword must still
contain valid data.
Example:
[Package]
| variable typ min max
R_pkg 250.0m 225.0m 275.0m
L_pkg 15.0nH 12.0nH 18.0nH
C_pkg 18.0pF 15.0pF 20.0pF
Page 21
Each line must contain either three or six columns. A pin line with three
columns only associates the pin's signal and model. Six columns can be used to
override the default package values (specified under [Package]) FOR THAT PIN
ONLY. When using six columns, the headers R_pin, L_pin, and C_pin must be
listed. If "NA" is in columns 4 through 6, the default packaging values must
be used. The headers R_pin, L_pin, and C_pin may be listed in any order.
Example:
[Pin] signal_name model_name R_pin L_pin C_pin
|
1 RAS0# Buffer1 200.0m 5.0nH 2.0pF
Page 22
Keyword: [Package Model]
Required: No
Description: Indicates the name of the package model to be used for the
component.
Usage Rules: The package model name is limited to 40 characters. Spaces are
allowed in the name. The name should include the company name or initials to
help ensure uniqueness. The EDA tool will search for a matching package model
name as an argument to a [Define Package Model] keyword in the current .ibs
file first. If a match is not found, the EDA tool will next look for a match
in an external .pkg file. If the matching package model is in an external .pkg
file, it must be located in the same directory as the .ibs file. The file
names of .pkg files must follow the rules for file names given in Section 3,
"GENERAL SYNTAX RULES AND GUIDELINES".
Other Notes: Use the [Package Model] keyword within a [Component] to indicate
which package model should be used for that component. The specification
permits .ibs files to contain [Define Package Model] keywords as well. These
are described under "Package Modeling" in Section 7. When package model
definitions occur within a .ibs file, their scope is "local", i.e., they are
known only within that .ibs file and no other. In addition, within that .ibs
file, they override any globally defined package models that have the same name.
Example:
[Package Model] QS-SMT-cer-8-pin-pkgs
Page 22
Keywords: [Alternate Package Models], [End Alternate Package Models]
Required: No
Description: Used to select a package model from a list of package models.
Usage Rules: The [Alternate Package Models] keyword can be used in addition
to the [Package Model] keyword. [Alternate Package Models] shall be used only
for components that use the [Package Model] keyword.
Each [Alternate Package Models] keyword specifies a set of alternate package
model names for only one component, which is given by the previous [Component]
keyword. The [Alternate Package Models] keyword shall not appear before the
first [Component] keyword in a .ibs file. The [Alternate Package Models]
keyword applies only to the [Component] section in which it appears, and must
be followed by an [End Alternate Package Models] keyword.
All alternate package model names must appear below the [Alternate Package
Models] keyword, and above the following [End Alternate Package Models]
keyword. The package model names listed under the [Alternate Package Models]
must follow the rules of the package model names associated with the [Package
Model] keyword. The package model names correspond to the names of package
models defined by [Define Package Model] keywords. EDA tools may offer users a
facility for choosing between the default package model and any of the
alternate package models, when analyzing occurrences of the [Component].
The package model named by [Package Model] can be optionally repeated in the
[Alternate Package Models] list of names.
Example:
[Alternate Package Models]
|
208-pin_plastic_PQFP_package-even_mode | Descriptive names are shown
208-pin_plastic_PQFP_package-odd_mode
208-pin_ceramic_PQFP_package-even_mode
208-pin_ceramic_PQFP_package-odd_mode
|
[End Alternate Package Models]
Page 136
1 Package Modeling
The [Package Model] keyword is optional. If more than the default RLC package
model is desired, use the [Define Package Model] keyword.
Use the [Package Model] keyword within a [Component] to indicate the package
model for that component. The specification permits .ibs files to contain the
following additional list of package model keywords. Note that the actual
package models can be in a separate <package_file_name>.pkg file or can exist
in the .ibs files between the [Define Package Model] ... [End Package Model]
keywords for each package model that is defined. For reference, these keywords
are listed in Table 14. Full descriptions follow. EDA tools that do not
support these keywords will ignore all entries between the [Define Package
Model] and [End Package Model] keywords.
Page 138
Keyword: [Define Package Model]
Required: Yes
Description: Marks the beginning of a package model description.
Usage Rules: If the .pkg file contains data for more than one package, each
section must begin with a new [Define Package Model] keyword. The length of the
package model name must not exceed 40 characters in length. Blank characters
are allowed. For every package model name defined under the [Package Model]
keyword, there must be a matching [Define Package Model] keyword.
Example:
[Define Package Model] QS-SMT-cer-8-pin-pkgs
Walter Katz
wkatz@xxxxxxxxxx<mailto:wkatz@xxxxxxxxxx>
Phone 303.449-2308
Mobile 303.335-6156
Other related posts:
