Browse Prior Art Database

Detailed Module I/O Assignment Based Upon High Level Design

IP.com Disclosure Number: IPCOM000109612D
Original Publication Date: 1992-Sep-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 5 page(s) / 305K

Publishing Venue

IBM

Related People

Aubertine, ME: AUTHOR [+2]

Abstract

SHUFFLE is a computer-aided design tool used by the TCM (Thermal Conduction Module) designer for detailed design work. Detailed design work for the TCM includes component placement, net cross-referencing, package I/O assignment, net ordering, and other tasks which are based on specific and detailed technology rules. For design tasks, such as I/O assignment, high-level design information has not been available to the SHUFFLE user in the past when making assignment decisions. The user has been required to have a complete set of detailed placement and technology rules before detailed design work could be performed on the TCM. The I/O assignments were based solely on either SHUFFLE algorithms dependent upon detailed design information or by designer decisions.

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Detailed Module I/O Assignment Based Upon High Level Design

       SHUFFLE is a computer-aided design tool used by the TCM
(Thermal Conduction Module) designer for detailed design work.
Detailed design work for the TCM includes component placement, net
cross-referencing, package I/O assignment, net ordering, and other
tasks which are based on specific and detailed technology rules.  For
design tasks, such as I/O assignment, high-level design information
has not been available to the SHUFFLE user in the past when making
assignment decisions.  The user has been required to have a complete
set of detailed placement and technology rules before detailed design
work could be performed on the TCM.  The I/O assignments were based
solely on either SHUFFLE algorithms dependent upon detailed design
information or by designer decisions.  Any previous high-level design
work was not considered when making the TCM I/O assignments in
SHUFFLE.

      PEPPER is a computer-aided design tool used by the TCM designer
for high-level design work.  The PEPPER tool, like SHUFFLE, allows
the TCM designer to perform tasks such as component placement, net
crossreferencing, package I/O assignment, and others.  High-level
design work means that the technology information used by the TCM
designer has not been finalized and, to a certain degree, can change
as the TCM technology is defined.  The technology information the TCM
designer uses in PEPPER is specific enough to allow many of the
issues, such as net criticality and congestion, to be resolved before
detailed technology information is available.  PEPPER allows the
designer to make approximate TCM I/O assignments on a design so that
solutions to net criticality and congestion problems can be
formulated before detailed design.

      The problem is that no consideration is made of the TCM I/Os
selected during high-level design when the designer is making TCM I/O
assignments during detailed design.  The I/O assignment algorithms
and data used during detailed design do not use the net priorities
and approximate I/O assignments selected during high-level design as
a guide for making the final I/O assignments.  The work done during
high-level design is lost because the algorithms and functions to
handle the high-level I/O assign information do not exist.  The
problems of congestion and net criticality and how they are affected
by the TCM I/O assignment must be completely revisited in detailed
design to insure technology constraints are not violated.

      This invention allows the TCM designer to use the TCM I/O
assignments selected in high-level design as a guide for making TCM
I/O assignments during detailed design.  The algorithm used by this
invention looks at the TCM I/O approximations and net priorities
generated during high-level design to select the best possible TCM
I/O during detailed design.  TCM I/O assignments are generated by
determining the location of the one or more chip I/Os...