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Conditional Placement Capability of Structured Logic Placement

IP.com Disclosure Number: IPCOM000101706D
Original Publication Date: 1990-Aug-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 1 page(s) / 42K

Publishing Venue

IBM

Related People

Seewann, E: AUTHOR

Abstract

Disclosed is conditional placement capability of a structured logic placement program, BTRTOGL1, described in the following article. This program has the ability to place (or not place) cells depending upon certain conditions being fulfilled in either the logic file or the placement field.

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Conditional Placement Capability of Structured Logic Placement

       Disclosed is conditional placement capability of a
structured logic placement program, BTRTOGL1, described in the
following article.  This program has the ability to place (or not
place) cells depending upon certain conditions being fulfilled in
either the logic file or the placement field.

      For example, instead of placing a 4W NAND circuit cell, the
program can place a core cell and a series of overlay cells depending
upon the number of pins used for the NAND in the logic file.

      A second example consists of placing different physical cells
depending upon where they are placed, i.e., even or odd bit
positions, etc.  Different rotations of the same cell may also be
placed depending upon where they are placed.

      Overlay cells may also be added or not, depending upon whether
specific input or output pins are used in the logic input file.  This
conditional capability can also be extended to cover the situations
in which cells are added only if specific pins are present in the BTR
and the cell is placed on a certain bit, word bus or page boundary.

      The program also has the ability to conditionally add cells,
the names of which must also be computed by the program.  For
example, the decode pin class is used to personalize wiring (decoder
personalization).  This conditional placement differs from that
previously described in that the cell placed is not conditional...