LTX - a system for the directed automatic design of LSI circuits

ABSTRACT

LTX is a minicomputer-based design system for large-scale integrated circuit chip layout which offers a flexible set of interactive and automatic procedures for translating a circuit connectivity description into a finished mask design. The system encompasses algorithms for two-dimensional placement, string placement, exploitation of equivalent terminals, decomposition of routing into channels, and channel routing. Circuit connectivity is preserved during interactive procedures. LTX runs on an H-P 2100 series computer with 32K of memory and disc. In current applications to polycell-style layouts, one to two weeks is typically required for completion of the layout design of an LSI chip containing 500 cells.

REFERENCES

• 1: H. Y. Chang, G. W. Smith, Jr. and R. B. Walford, "LAMP: System Description," B.S.T.J. 53, No.8, p.1431 (1974)
• 2: B.R. Fowler, "XYMASK," Bell Laboratories Record 47, No.6, p.204 (July 1969)
• 3: G. Persky , H. K. Gummel, GRAFOS - A symbolic routing language, Proceedings of the 10th workshop on Design automation, p.173-181, June 25-27, 1973
• 4: D. G. Schweikert, "PLAC - A Partitioning-Placement Program for Modular IC Layout," Proceedings of the 13th Design Automation Conference (1976)
• 5: David N. Deutsch, A “Dogleg” channel router, Proceedings of the 13th conference on Design automation, p.425-433, June 28-30, 1976, San Francisco, California, United States [doi>10.1145/800146.804843]
• 6: G. Persky, PRO - an automatic string placement program for polycell layout, Proceedings of the 13th conference on Design automation, p.417-424, June 28-30, 1976, San Francisco, California, United States [doi>10.1145/800146.804842]
• 7: P. Kozak , H. K. Gummel , B. R. Chawla, Operational features of an MOS timing simulator, Proceedings of the 12th conference on Design automation, p.95-101, January 1975
• 8: "Moving-Head Disc Operating System," Hewlett-Packard Company, Cupertino, California (March 1971)
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INDEX TERMS

Primary Classification:
  B. Hardware
  B.6 LOGIC DESIGN
      B.6.3 Design Aids
          Subjects: Automatic synthesis

Additional Classification:
  B. Hardware
  B.7 INTEGRATED CIRCUITS
      B.7.2 Design Aids
          Subjects: Layout

  F. Theory of Computation
  F.2 ANALYSIS OF ALGORITHMS AND PROBLEM COMPLEXITY
      F.2.2 Nonnumerical Algorithms and Problems
          Subjects: Routing and layout

  J. Computer Applications
  J.6 COMPUTER-AIDED ENGINEERING
      Subjects: Computer-aided design (CAD)

General Terms:
Algorithms, Design