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United States Patent | 5,481,473 |
Kim , et al. | January 2, 1996 |
A computer-based system and method is provided for creating a representation of interconnections between VLSI circuit design components. A VLSI circuit design component identifying a leaf design entity is stored in memory. Placements in the design where the design component appears are stored in memory. A set of links is formed to connect placements to one another. The links further specify placement of the design component in the circuit design. The interconnections themselves are then computed. The interconnections denote where placements of the VLSI circuit design component instances are interconnected, and may specify any meaningful coupling, such as electrical conductivity, magnetic, or optical. The interconnections are represented by a nested net graph which includes a list of nets, and instance counts associated with the nets. The nested net graph may also include a second list, which specifies instances of lower nested nets contained in the nested net graph. The nested net graph may further include a shape-to-net table attached at the root of the nested net graph. The shape-to-net table defines a mapping from the VLSI circuit design component to a corresponding net. Also provided is a system and method for building interconnections using a bridge component, or bridge net. The bridge net denotes the interconnection between two nets derived from a pair of VLSI circuit design component instances.
Inventors: | Kim; Young O. (San Jose, CA), Russell; Philip J. (Alresford, GB), Weinert; Glenwood S. (San Jose, CA) |
Assignee: |
International Business Machines Corporation
(Armonk,
NY)
|
Appl. No.: | 08/019,970 |
Filed: | February 19, 1993 |
Current U.S. Class: | 716/111 |
Current International Class: | G06F 17/50 (20060101); H01L 021/70 () |
Field of Search: | 364/488,489,490,491,148,474.13,474.24,474.25,221.2,221.8 395/600 |
4554625 | November 1985 | Otten |
4815003 | March 1989 | Putatunda et al. |
4831543 | May 1989 | Mastellone |
5146583 | September 1992 | Matsunaka et al. |
5249133 | September 1993 | Batra |
5262959 | November 1993 | Chkoreff |
5267175 | November 1993 | Hooper |
N Hedenstierna et al., "The Use Of Inverse Layout Trees For Hierarchical Design Rule Checking", Design Automation Conference, 1989, Paper 32.2, pp. 508-512. . C. K. Nandy et al., "Linear Time Geometrical Design Rule Checker Based On Quadtree Representation of VLSI Mask Layouts", Computer-Aided Design, vol. 18, No. 7, Sep. 1986, pp. 380-388. . C. Niessen, "Hierarchical Design Methodologies And Tools For VLSI Chips", Proceedings Of The IEEE, vol. 71, No. 1, Jan. 1983, pp. 66-75. . T. Whitney, "A Hierarchical Design-Rule Checking Algorithm", LAMBDA, First Quarter 1981, pp. 40-43.. |