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US5047949A Expired / Lapsed US ⏱️ 0.0 years remaining

Standard cell LSI layout method

Assignee: Panasonic Holdings Corp
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Filing: 1990-06-06
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Granted: 1991-09-10
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Expires: 2010-06-06
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Abstract

Abstract In a standard cell LSI including functional circuits formed by placing a group of cell rows consisting of standard cells selected from a group of standard cells and by routing the standard cells, a standard cell LSI layout method including the steps of comparing the routing density in routing areas located between the cell rows and bending the cell rows by shifting one or more of the standard cells in a direction of a more dispersed routing area from a more congested routing area. The cell rows are bent at a point between each high congested area of the routing area which encloses the cell rows depending on the routing density. A link cell may be provided for linking power and ground pins of the standard cells which have been shifted in position and which compose the bent cell rows. The link cell may be stored in a library in a system of composing the cell rows by storing the standard cells in a library and referring to the standard cells from the library in defining a standard cell LSI layout.

Inventors

  • 👤 Ryuichi Yamaguchi
  • 👤 Atsushi Yamamoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 12:48
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/90; G; G06; G06F; G06F30/00; G06F30/30; G06F30/39; H10D89/00

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 156 words
In a standard cell LSI comprising functional circuits formed by placing a plurality of cell rows consisting of a plurality of standard cells and by routing said standard cells, a standard cell LSI layout method comprising the steps of: deciding a global routing path which connects signal pins of said standard cells; and determining the routing density from said global routing path in routing channels between cell rows; and bending said cell rows in a zigzag lien by shifting one or more of said standard cells in a direction of a more dispersed routing area from a more congested routing area in order to avoid congested routing area between said cell rows; and shifting at least one cell row in order to eliminate wiring area containing no wiring between said cell rows, which is produced as a result of bending of cell rows; and connecting said signal pins of said standard cells by generating routing patterns.
Claim 2
Dependent Claim 156 words
In a standard cell LSI comprising functional circuits formed by placing a plurality of cell rows consisting of a plurality of standard cells and by routing said standard cells, a standard cell LSI layout method comprising the steps of: deciding a global routing path which connects signal pins of said standard cells; and determining the routing density from said global routing path in routing channels between cell rows; and bending said cell rows in a zigzag lien by shifting one or more of said standard cells in a direction of a more dispersed routing area from a more congested routing area in order to avoid congested routing area between said cell rows; and shifting at least one cell row in order to eliminate wiring area containing no wiring between said cell rows, which is produced as a result of bending of cell rows; and connecting said signal pins of said standard cells by generating routing patterns.
Claim 3
Dependent Claim 47 words
A standard cell LSI layout method according to claim 1, further comprising the step of providing at least one link cell for linking power and ground pins of said standard cells which have been shifted in position and which compose the cell rows which have been bent.

References Cited (Backward Citations)

US4636965A Cited
US4686629A Cited
US4613941A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-09-09 1995-03-11 1995-09-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-09-09 1999-03-11 1999-09-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-09-09 2003-03-11 2003-09-10 $7700.00 Window Closed / Lapsed

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