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Macro/ Cell Compiler Custom Realization for Disjoint or Integrated Logical and Physical Design Databases

IP.com Disclosure Number: IPCOM000121681D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 6 page(s) / 242K

Publishing Venue

IBM

Related People

Correale Jr, A: AUTHOR [+3]

Abstract

Many of today's silicon compilers (cell or macro) are based on common design databases wherein both the logic and physical design data are shared. The advantages of utilizing common databases are many, the most significant being the generation of physical data, i.e., that data needed for chip manufacture, directly from the logical database specifications. The resulting compilations are generally a direct mapping from the logic database. That is, there exists a physical entity or assemblage of entities that map directly for each respective logic statement, including the ordering of said statements within the specification. Disjoint databases generally operate in the same manner, with the exception that back annotation must be done manually, and database integrity is more difficult to assure.

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This is the abbreviated version, containing approximately 27% of the total text.

Macro/ Cell Compiler Custom Realization for Disjoint or Integrated
Logical and Physical Design Databases

      Many of today's silicon compilers (cell or macro) are
based on common design databases wherein both the logic and physical
design data are shared.  The advantages of utilizing common databases
are many, the most significant being the generation of physical data,
i.e., that data needed for chip manufacture, directly from the
logical database specifications.  The resulting compilations are
generally a direct mapping from the logic database.  That is, there
exists a physical entity or assemblage of entities that map directly
for each respective logic statement, including the ordering of said
statements within the specification.  Disjoint databases generally
operate in the same manner, with the exception that back annotation
must be done manually, and database integrity is more difficult to
assure.  The direct correspondence between logic and physical design
databases is the same as described for the common database.

      This article describes a technique which allows, through the
use of an auxiliary datafile or database, herein referred to as a
userfile, in conjunction with a silicon compiler, the resulting
physical compilation to be tailored to the specific needs of the
physical design without having to alter the logic design database.
In essence, a multiplicity of physical realizations are now possible
for a given logic specification, including bit ordering and
placement, without altering or back annotating the logic database.
This approach can be used with either integrated or disjoint
databases.

      Fig. 1 illustrates the flow diagram of a cell/macro compiler.
The three entities shown are the logic database, physical database
and the compiler.

      The logic database contains the defined logic blocks and their
interconnections.  These logic blocks can be primitive logic
functions, such as AND and OR gates, or be higher level
representations of groups of blocks, such as registers, which may in
themselves be comprised of primitive latch types and integrated
control or clocking components.

      The physical database contains the graphics data associated
with each of the cells needed to implement the logic blocks or
macros.  The simple primitive AND gate may be represented as a single
physical cell or as a collection of sub-cells, the inter-relationship
of such sub- cells being specified within the compiler.  These
inter-relationships are referred to as relationship rules.

      The compiler contains all the procedural rules and programs for
assembling the physical sub-cells to create the one-for-one
correspondence to the logic database-defined- macro entity.  In
addition, the compiler may also generate logic statements describing
the macro consistent with its physical realization.

      The relationship rules generally specify which cells or
sub-cells are to be utilized in the creation...