DocumentCode :
332768
Title :
Shaping a VLSI wire to minimize delay using transmission line model
Author :
Youxin Gao ; Wong, D.F.
Author_Institution :
Dept. of Comput. Sci., Texas Univ., Austin, TX, USA
fYear :
1998
fDate :
8-12 Nov. 1998
Firstpage :
611
Lastpage :
616
Abstract :
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 Elmore delay model (W.C. Elmore, 1948). 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/sup -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.
Keywords :
VLSI; circuit layout CAD; delays; digital integrated circuits; integrated circuit interconnections; integrated circuit layout; transient analysis; transient response; transmission line theory; Elmore delay model; VLSI wire; continuous wire sizing optimization; delay minimization; diffusion equation; non uniform wires; shape function; time domain; transient response; transmission line model; wire shape function; Delay effects; Delay estimation; Delay lines; Equations; Integrated circuit interconnections; Permission; Shape; Transmission lines; Very large scale integration; Wire;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Computer-Aided Design, 1998. ICCAD 98. Digest of Technical Papers. 1998 IEEE/ACM International Conference on
Conference_Location :
San Jose, CA, USA
Print_ISBN :
1-58113-008-2
Type :
conf
DOI :
10.1109/ICCAD.1998.144332
Filename :
743079
Link To Document :
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