Patent US5731985A successfully refreshed from Google Patents.
US5731985A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chip sizing for hierarchical designs
Assignee: International Business Machines Corp
•
Filing: 1996-04-23
•
Granted: 1998-03-24
•
Expires: 2016-04-23
Abstract
Abstract A method for resizing the macro cells' boundaries of an integrated chip is disclosed and that becomes effectual after the initial floorplanning process has been completed. The method of the present invention apportions any excess area that is freed-up after the initial floorplanning process by altering the sizes or dimensions of the macro cell within the hierarchy of the integrated circuit in such a manner that the fractional change in the percentage occupancy is substantially constant among all macro cells at all hierarchy levels.
Inventors
- 👤 Rajesh Gupta
- 👤 John Youssef Sayah
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:41
CPC Classifications
G; G06; G06F; G06F30/00; G06F30/30; G06F30/39; G06F30/392
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
66 words
A method of apportioning increased area of a parent cell to child macro cells of a hierarchical integrated circuit design, comprising the steps of: a) determining parent growth factors in X and Y directions for the parent cell; b) determining child growth factors in X and Y directions for the child cell according to a geometric progression based on the growth factors of the parent cell.
Claim 2
Independent Claim
66 words
A method of apportioning increased area of a parent cell to child macro cells of a hierarchical integrated circuit design, comprising the steps of: a) determining parent growth factors in X and Y directions for the parent cell; b) determining child growth factors in X and Y directions for the child cell according to a geometric progression based on the growth factors of the parent cell.
Claim 3
Dependent Claim
88 words
The method of claim 1 wherein the child growth factors are determined according to the formulas: CFX=PFX.sup.((d'-d)/(d'-d+1)) ( 1) CFY=PFY.sup.((d'-d)/(d'-d+1)) ( 2) where CFX=growth factor in the X direction for the child cell; PFX=growth factor in the X direction for the parent cell; CFY=growth factor in the Y direction for the child cell; PFY=growth factor in the Y direction for the parent cell; d'=highest depth value among all leaf cells that are descendants of the child macro cell; and d=depth in the hierarchy of the child macro cell.
Claim 4
Dependent Claim
102 words
The method of claim 1 wherein the hierarchy has a top level cell, macro cells, and leaf cells with all the leaf cells having the same depth, and the child growth factors are determined according to the formulas: CFX=FX.sup.((D-d)/(d-1)) ( 1) CFY=FY.sup.((D-d)/(D-1)) ( 2) where CFX=growth factor in the X direction for the child cell; FX=growth factor in the X direction for the top level cell; CFY=growth factor in the Y direction for the child cell; FY=growth factor in the Y direction for the top level cell; D=depth of the leaf cells; and d=depth in the hierarchy of the child macro cell.
Claim 5
Dependent Claim
55 words
The method of claim 1 wherein a child macro cell is reused, further comprising the steps of: (c) identifying all instances of reuse; (d) fixing the growth factor of the reused child macro cell as the most restrictive of all the determined growth factors for each instance of reuse according to steps (a) and (b).
Claim 6
Dependent Claim
44 words
The method of claim 4 wherein more than one child macro cell is reused, further comprising: (e) reevaluating and adjusting as necessary the growth factors for the hierarchy in a recursive manner after the growth factor for each reused child macro cell is fixed.
Claim 7
Dependent Claim
11 words
The method of claim 1 wherein the parent cell is non-rectangular.
Claim 8
Dependent Claim
11 words
The method of claim 1 wherein the parent cell is rectangular.
Claim 9
Dependent Claim
87 words
A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform the method steps for apportioning increased area of a parent cell to child macro cells of a hierarchical integrated circuit design, said method steps comprising: a) determining parent growth factors in X and Y directions for the parent cell; b) determining child growth factors in X and Y directions for the child cell according to a geometric progression based on the growth factors of the parent cell.
Claim 10
Dependent Claim
87 words
A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform the method steps for apportioning increased area of a parent cell to child macro cells of a hierarchical integrated circuit design, said method steps comprising: a) determining parent growth factors in X and Y directions for the parent cell; b) determining child growth factors in X and Y directions for the child cell according to a geometric progression based on the growth factors of the parent cell.
Claim 11
Dependent Claim
90 words
The program storage device of claim 8 wherein the child growth factors are determined according to the formulas: CFX=PFX.sup.((d'-d)/(d'-d+1)) ( 1) CFY=PFY.sup.((d'-d)/(d'-d+1)) ( 2) where CFX=growth factor in the X direction for the child cell; PFX=growth factor in the X direction for the parent cell; CFY=growth factor in the Y direction for the child cell; PFY=growth factor in the Y direction for the parent cell; d'=highest depth value among all leaf cells that are descendants of the child macro cell; and d=depth in the hierarchy of the child macro cell.
Claim 12
Dependent Claim
104 words
The program storage device of claim 8 wherein the hierarchy has a top level cell, macro cells, and leaf cells with all the leaf cells having the same depth, and the child growth factors are determined according to the formulas: CFX=FX.sup.((D-d)/(D-1)) ( 1) CFY=FY.sup.((D-d)/(D-1)) ( 2) where CFX=growth factor in the X direction for the child cell; FX=growth factor in the X direction for the top level cell; CFY=growth factor in the Y direction for the child cell; FY=growth factor in the Y direction for the top level cell; D=depth of the leaf cells; and d=depth in the hierarchy of the child macro cell.
Claim 13
Dependent Claim
56 words
The program storage device of claim 8 wherein a child macro cell is reused, further comprising the steps of: (c) identifying all instances of reuse; (d) fixing the growth factor of the reused child macro cell as the minimum of all the determined growth factors for each instance of reuse according to steps (a) and (b).
Claim 14
Dependent Claim
46 words
The program storage device of claim 8 wherein more than one child macro cell is reused, further comprising: (e) reevaluating and adjusting as necessary the growth factors for the hierarchy in a recursive manner after the growth factor for each reused child macro cell is fixed.
Claim 15
Dependent Claim
13 words
The program storage device of claim 8 wherein the parent cell is non-rectangular.
Claim 16
Dependent Claim
13 words
The program storage device of claim 8 wherein the parent cell is rectangular.
References Cited (Backward Citations)
US5095356A
Cited
US4577276A
Cited
US4918614A
Cited
US5146343A
Cited
US5187668A
Cited
US5420800A
Cited
US5208759A
Cited
US5398195A
Cited
US5418733A
Cited
US5416722A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-03-23 | 2001-09-22 | 2002-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-03-23 | 2005-09-22 | 2006-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-03-23 | 2009-09-22 | 2010-03-24 | $7700.00 | Window Closed / Lapsed |