US6249902B1
Expired / Lapsed
US
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Design hierarchy-based placement
Assignee: RELAY DESIGN AUTOMATION Inc
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Filing: 1998-01-09
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Granted: 2001-06-19
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Expires: 2018-01-09
Abstract
Abstract In computer-aided electronic design automation software, a placement system biases clustering of cells according to their hierarchical design while optimizing placement for controlling die size and total wire length. The placement system also provides for slack distribution, row improvement and randomization during partitioning. Floor plans based on trial placement and placement guiding blocks are also described.
Inventors
- 👤 Mitsuru Igusa
- 👤 Hsi-Chuan Chen
- 👤 Shiu-Ping Chao
- 👤 Wei-Jin Dai
- 👤 Daw Yang Shyong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:14
CPC Classifications
G; G06; G06F; G06F30/00; G06F30/30; G06F30/39; G06F30/392
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
226 words
A method for determining placement of a circuit within a substrate area of an integrated circuit chip, wherein the circuit is defined as comprising a plurality of logic modules, each logic module including a plurality of cells, the circuit being further defined as comprising connections for carrying signals between said cells, the method comprising the steps of: a. generating a trial placement by initially assigning each cell of said circuit to a position within the substrate area in a manner that is biased towards clustering cells of the same logic module while satisfying other positioning criteria; b. identifying a plurality of module core areas within the substrate area, each module core area corresponding to a separate one of the logic modules and encompassing assigned positions of cells of the corresponding logic module; c. defining a plurality of rectangular guiding blocks, each guiding block corresponding to a separate one of the module core areas and being sized relative to its corresponding module core area; d. assigning each guiding block to a position within said substrate area; and e. generating a second placement by reassigning each cell of said circuit to a position within the substrate area in a manner that is biased towards positioning cells of each logic module in a vicinity of the guiding block corresponding to the logic module while satisfying said other positioning criteria.
Claim 2
Independent Claim
226 words
A method for determining placement of a circuit within a substrate area of an integrated circuit chip, wherein the circuit is defined as comprising a plurality of logic modules, each logic module including a plurality of cells, the circuit being further defined as comprising connections for carrying signals between said cells, the method comprising the steps of: a. generating a trial placement by initially assigning each cell of said circuit to a position within the substrate area in a manner that is biased towards clustering cells of the same logic module while satisfying other positioning criteria; b. identifying a plurality of module core areas within the substrate area, each module core area corresponding to a separate one of the logic modules and encompassing assigned positions of cells of the corresponding logic module; c. defining a plurality of rectangular guiding blocks, each guiding block corresponding to a separate one of the module core areas and being sized relative to its corresponding module core area; d. assigning each guiding block to a position within said substrate area; and e. generating a second placement by reassigning each cell of said circuit to a position within the substrate area in a manner that is biased towards positioning cells of each logic module in a vicinity of the guiding block corresponding to the logic module while satisfying said other positioning criteria.
Claim 3
Dependent Claim
16 words
The method in accordance with claim 1 further comprising the step of iteratively repeating steps b-e.
Claim 4
Dependent Claim
62 words
The method in accordance with claim 1 wherein step a comprises the substeps of: a1. partitioning the substrate area into a plurality of first partitions; and a2. initially assigning cells of said circuit to positions within said first partitions in a manner that is biased towards clustering of cells included in each logic module within a same one of said first partitions.
Claim 5
Dependent Claim
38 words
The method in accordance with claim 3 wherein step a further comprises the step of: a3. reassigning at least one of said cells to a new position within said substrate area so as to satisfy a placement criterion.
Claim 6
Dependent Claim
78 words
The method in accordance with claim 4 wherein for each of said plurality of first partitions, step a further comprises the substeps of: a4. further partitioning said first partition into a plurality of second partitions; and a5. reassigning cells assigned at step a2 to positions within said first partition to positions within said second partitions in a manner that is biased towards clustering of cells included in each logic module within a same one of said second partitions.
Claim 7
Dependent Claim
34 words
The method in accordance with claim 5 further comprising the step of a6. reassigning cells assigned at step a5 to new positions within said substrate area so as to satisfy said other placement criteria.
Claim 8
Dependent Claim
39 words
The method in accordance with claim 1 wherein in step b, the module core area corresponding to each logic module is identified as a largest contiguous portion of said substrate area containing only cells included in the logic module.
Claim 9
Dependent Claim
40 words
The method in accordance with claim 1 wherein each guiding block defined in step c has a height and width of a similar ratio as a height and width of a minimum rectangular area encompassing its corresponding module core area.
Claim 10
Dependent Claim
80 words
The method in accordance with claim 1 wherein step c comprises the substeps of: c1. defining said plurality of guiding blocks within the substrate area, each guiding block corresponding to a separate one of the module core areas, each guiding block defining a rectangular portion of the substrate area sized and positioned in relation to its corresponding module core area; and c2. adjusting dimensions and positions of said guiding blocks within the substrate area to reduce overlapping of guiding blocks.
Claim 11
Dependent Claim
27 words
The method in accordance-with claim 9 wherein the guiding block dimensions are adjusted in step c2 in relation to cell densities of the corresponding module core areas.
Claim 12
Dependent Claim
87 words
The method in accordance with claim 1 wherein step c comprises the substeps of: c1. defining said plurality of guiding blocks within the substrate area, each guiding block corresponding to a separate one of the module core areas, each guiding block defining a rectangular portion of the substrate area sized and positioned in relation to its corresponding module core area; and c2. adjusting dimensions and positions of said guiding blocks within the substrate area to reduce overlapping of guiding blocks and to adjust spacing between guiding blocks.
Claim 13
Dependent Claim
23 words
The method in accordance with claim 1 wherein in step d the guiding block are assigned to non-overlapping positions within said substrate area.
Claim 14
Independent Claim
181 words
A method for determining placement of a circuit within a substrate area of an integrated circuit chip, wherein the circuit is defined as comprising a plurality of logic modules, each logic module including a plurality of cells, the circuit being further defined as comprising connections for carrying signals between said cells, the method comprising the steps of: a. partitioning the substrate area into N first partitions wherein N is an integer greater than 1 ; b. identifying the cells included in each logic module and initially assigning the cells to positions within said first partitions such that at most N- 1 of said plurality of logic modules are divided, wherein cells of a divided module are assigned to more than one of said first partitions, and such that all others of said logic modules are undivided, wherein all cells of an undivided logic module are assigned to only one of said first partitions; and c. reassigning at least one of said cells of the divided module to a new position within said substrate area so as to satisfy a placement criterion.
Claim 15
Independent Claim
181 words
A method for determining placement of a circuit within a substrate area of an integrated circuit chip, wherein the circuit is defined as comprising a plurality of logic modules, each logic module including a plurality of cells, the circuit being further defined as comprising connections for carrying signals between said cells, the method comprising the steps of: a. partitioning the substrate area into N first partitions wherein N is an integer greater than 1 ; b. identifying the cells included in each logic module and initially assigning the cells to positions within said first partitions such that at most N- 1 of said plurality of logic modules are divided, wherein cells of a divided module are assigned to more than one of said first partitions, and such that all others of said logic modules are undivided, wherein all cells of an undivided logic module are assigned to only one of said first partitions; and c. reassigning at least one of said cells of the divided module to a new position within said substrate area so as to satisfy a placement criterion.
Claim 16
Dependent Claim
117 words
The method in accordance with claim 13 further comprising the steps of: d. further partitioning each said first partition into M second partitions where M is an integer greater than 1; and e. identifying all cells included in each logic module and reassigning cells assigned at step c to positions within said first partition to positions within said second partitions such that at most M−1 of said plurality of logic modules are divided, wherein cells of a divided module are assigned to more than one of said second partitions, and such that all others of said logic modules are undivided, wherein all cells of an undivided logic module are assigned to only one of said second partitions.
Claim 17
Dependent Claim
33 words
The method in accordance with claim 14 further comprising the step of f. reassigning cells assigned at step e to new positions within said substrate area so as to satisfy a placement criterion.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-06-18 | 2004-12-18 | 2005-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-06-18 | 2008-12-18 | 2009-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-06-18 | 2012-12-18 | 2013-06-19 | $7700.00 | Window Closed / Lapsed |