Improved Signal Delay Bounds for RC Tree Networks

Abstract : Paul Penfield and collaborators have derived upper and lower bounds on the step response of RC tree networks used to model device interconnections in MOS integrated circuits Rubinstein, Penfield, and Horowitz. These bounds are computationally efficient and hence suited for use in computer aided design programs for timing analysis. The main result of this paper, Theorem 1, allows us to replace the time constant T sub p in the original bounds by a new one T sub pi or = T sub p, thereby tightening the original bounds given by Rubinstein, Penfield, and Horowitz.