Placement-Driven Physical-Hierarchy Generation
First Claim
1. An automated method for physical hierarchy generation, the method comprising:
- receiving a virtually-flat placement of a logically hierarchical design having a plurality of cells;
calculating a placement affinity metric in response to receiving the virtually-flat placement; and
coarsening the plurality of cells by clustering cells in the logically hierarchical design using the calculated placement affinity metric.
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Accused Products
Abstract
A method and system for performing placement-driven physical hierarchy generation in the context of an integrated circuit layout generation system is provided. This generation optimizes the physical hierarchy to improve placement of the cells in the layout, and the associated interconnect routability and delay. A new pre-clustering phase is introduced to maintain as much of the input logical hierarchy as possible while maintaining physical hierarchy quality. And a new cost function is described which is based on measuring the mutual affinity of cells in a virtually-flat placement. The new cost function is used during the new pre-clustering phase, as well as the common clustering, partitioning, and declustering/refinement phases of physical hierarchy generation.
67 Citations
37 Claims
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1. An automated method for physical hierarchy generation, the method comprising:
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receiving a virtually-flat placement of a logically hierarchical design having a plurality of cells;
calculating a placement affinity metric in response to receiving the virtually-flat placement; and
coarsening the plurality of cells by clustering cells in the logically hierarchical design using the calculated placement affinity metric. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An automated method for physical hierarchy generation, the method comprising:
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receiving a virtually-flat placement of a logically hierarchical design comprising a plurality of cells clustered into initial partitions;
calculating a placement affinity metric; and
refining the initial partitions by moving at least one cluster between the initial partitions, wherein the at least one cluster is selected using the placement affinity metric. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A computer readable storage medium for physical hierarchy generation, the computer readable storage medium storing instructions executable by a processing system, the instructions when executed cause the processing system to:
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receive a virtually-flat placement of a logically hierarchical design having a plurality of cells;
calculate a placement affinity metric in response to receiving the virtually-flat placement; and
coarsen the plurality of cells by clustering cells in the logically hierarchical design using the calculated placement affinity metric. - View Dependent Claims (29, 30, 31, 32, 33, 34)
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35. A computer readable storage medium for physical hierarchy generation, the computer readable storage medium storing instructions executable by a processing system, the instructions when executed cause the processing system to:
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receive a virtually-flat placement of a logically hierarchical design comprising a plurality of cells clustered into initial partitions;
calculate a placement affinity metric; and
refine the initial partitions by moving at least one cluster between the initial partitions, wherein the at least one cluster is selected using the placement affinity metric. - View Dependent Claims (36, 37)
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Specification