Shaping a VLSI wire to minimize delay using transmission line model

Youxin Gao, D. F. Wong

Research output: Chapter in book/report/conference proceedingConference proceedingpeer-review

19 Citations (Scopus)


In this paper, we consider continuous wire-sizing optimization for non-uniform wires. Our objective is to find the shape function of a wire which minimizes delay. This problem has been studied recently under the Elm ore delay model. However, it is well known that Elmore delay is only a rough estimate of the actual delay and thus more accurate models should be used to determine the wire shape function. Our study uses the transmission line model which gives a very accurate estimation of the actual delay. Since previous studies under Elmore delay model suggest that exponential wire shape is effective for delay minimization, we restrict the wire shape function to be of the form f(x) = ae-bx. By solving the diffusion equation, we derive the transient response in the time domain as a function of a and b for both step and ramp input. The coefficients a and b are then determined so that the actual delay (50% delay) is minimized. Our algorithm is very efficient. In all the experiments we performed, the wire shape functions can be determined in less than 1 second.

Original languageEnglish
Title of host publicationICCAD '98
Subtitle of host publicationProceedings of the 1998 IEEE/ACM International Conference on Computer-Aided Design
PublisherAssociation for Computing Machinery (ACM)
Number of pages6
ISBN (Print)9781581130089
Publication statusPublished - 8 Nov 1998
Event1998 IEEE International Conference on Computer-Aided Design, ICCAD 1998 - San Jose, United States
Duration: 8 Nov 199812 Nov 1998 (Conference proceedings)

Publication series

NameIEEE/ACM International Conference on Computer-Aided Design, Digest of Technical Papers
ISSN (Print)1092-3152
ISSN (Electronic)1558-2434


Conference1998 IEEE International Conference on Computer-Aided Design, ICCAD 1998
Country/TerritoryUnited States
CitySan Jose
Internet address

Scopus Subject Areas

  • Software
  • Computer Science Applications
  • Computer Graphics and Computer-Aided Design


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