All:
TSIRD2 which refrences
http://www.eda.org/ibis/tsirds/tsird2.pdf
is submitted for introduction at the June 11, 2010
IBIS teleconference meeting
Bob
Touchstone Issue Resolution Document (TSIRD)
TSIRD ID#: 2
ISSUE TITLE: Binary Format Support
REQUESTER: Michael Mirmak, Intel Corp. for Interconnect Task Group
DATE SUBMITTED: June 9, 2010
DATE ACCEPTED BY IBIS OPEN FORUM:
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STATEMENT OF THE ISSUE:
Touchstone files describing large numbers of ports and/or port interactions
can have significant filesizes (in the tens of megabytes). Such files can
be difficult to distribute and parse.
This TSIRD proposes an optional binary format for the numerical data under the
[Network Data] and [Noise Data] keywords. This format would replace the ASCII
data under those keywords in earlier Touchstone versions.
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STATEMENT OF THE RESOLVED SPECIFICATIONS:
TSIRD2 proposes adding a new keyword to support binary data representation of
network and noise data. This keyword, [Binary], is hierarchically scoped
within the [Network Data] and [Noise Data] keywords in Touchstone.
A full set of rules is described in tsird2.pdf:
http://www.eda.org/ibis/tsirds/tsird2.pdf
This file's text is intended for inclusion as a new keyword section in the
Touchstone specification.
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ANALYSIS PATH/DATA THAT LED TO SPECIFICATION:
Note that a binary format for Touchstone was originally proposed by Sam
Chitwood of Sigrity in July 2007. Anecdotal data from IBIS Ad Hoc Interconnect
Task Group members suggests binary data sets occupy only 20 to 33 percent of the
space taken by ASCII sets describing the same structures. Connector and package
interconnects are the most likely candidates for binary treatment.
In the course of development, several decisions were made.
- This proposal applies to Touchstone 2.1 and above. While the original
proposal was related to a Touchstone 1.0 application, the formal implementation
of a binary option would be adopted in practice with a new Touchstone format.
Tool vendors are not likely to add such a feature to a legacy format.
- The full set of Touchstone keywords is available when [Binary] is used. There
was consideration that the [Noise Data] keyword and [End] keyword would be
excluded, as the end of the binary data section would thought to be hard to
determine in a mixed-format environment. However, there is sufficient size
information in the [Binary] section, in combination with the other keyword
options, for determining exactly where the binary data ends.
- As a generalization, the [Binary] keyword may be used for either or both
[Network Data] and [Noise Data].
- An explicit set of arguments (32-Bit 64-Bit, Big-Endian, Little-Endian) was
chosen for clarity, rather than a more cryptic, packed 3-letter sequence (such
as "FDB" for Floating Point, Double, Big-Endian).
- The frequency precision is handled separately from the N-port data or noise
data precision because higher precision frequency information is sometimes
required for reasonance detection. This detection does not necesarily require
similarly high precision for the data entries.
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ANY OTHER BACKGROUND INFORMATION:
The binary format assumes the existence of a conversion utility, possibly part
of a parsing program, that would convert a legal Touchstone 2.x file using
ASCII data into a legal Touchstone 2.x file using binary data with the appropriate
[Binary] keyword and associated arguments.
While only 32- and 64-bit architectures are supported here, the specification
can be easily extended in future to cover alternatives.
Many people in the IBIS Ad Hoc Interconnect Task Group made key suggestions or
observations in preparing this material.
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-- Bob Ross Teraspeed Consulting Group LLC Teraspeed Labs 121 North River Drive 13610 SW Harness Lane Narragansett, RI 02882 Beaverton, OR 97008 401-284-1827 503-430-1065 http://www.teraspeed.com 503-246-8048 Direct bob@teraspeed.com Teraspeed is a registered service mark of Teraspeed Consulting Group LLC -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. -------------------------------------------------------------------- |For help or to subscribe/unsubscribe, e-mail majordomo@eda-stds.org |with the appropriate command message(s) in the body: | | help | subscribe ibis <optional e-mail address, if different> | subscribe ibis-users <optional e-mail address, if different> | unsubscribe ibis <optional e-mail address, if different> | unsubscribe ibis-users <optional e-mail address, if different> | |or e-mail a request to ibis-request@eda-stds.org. | |IBIS reflector archives exist under: | | http://www.eda-stds.org/pub/ibis/email_archive/ Recent | http://www.eda-stds.org/pub/ibis/users_archive/ Recent | http://www.eda-stds.org/pub/ibis/email/ E-mail since 1993Received on Wed Jun 9 13:28:36 2010
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