Table of Contents
VLSI Design
Volume 9, Issue 2, Pages 105-117

Optimal Differential Routing based on Finite State Machine Theory

1Department of Computer Science, Rensselaer Polytechnic Institute, Troy, N.Y. 12181, USA
2Department of EE&CS, West Point, N.Y. 10996, USA
3Center for Integrated Electronics, Rensselaer Polytechnic Institute, Troy, N.Y. 12181, USA
4L.L.C., 101 Park Ave (47th Flower), New York, N.Y. 10178, USA

Received 11 November 1995; Revised 31 March 1997

Copyright © 1999 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Noise margins in high speed digital systems continue to erode. Full differential signal routing provides a mechanism for deferring these effects. This paper proposes a three stage routing process for solving the adjacent placement routing problem of differential signal pairs, and proves that it is optimal. The process views differential pairs as logical nets; routes the logical nets; then bifurcates the result to achieve a physical realization. Finite state machine theory provides the critical theoretical underpinning and formal proof of correctness necessary for linear time bifurcation. Regular expressions map the theoretical solution to an appropriate implementation strategy that employs feature vectors for net recognition.