Date of Award


Degree Name

Master of Science


Computer Science

First Advisor

Dr. Naveed A. Sherwani

Second Advisor

Dr. Fred Boals

Third Advisor

Dr. Ajay Gupta

Access Setting

Masters Thesis-Open Access


In this thesis, we study two VLSI layout problems.

We investigate the Minimum-Bend Single Row Routing Problem in which the objective function is to minimize the number of doglegs (or blends) per net. Our approach uses a graph theoretic representation in which an instance of the Single Row Routing Problem is represented by three graphs, an overlap graph, a containment graph and an interval graph. Using this graph representation, we develop three algorithms for minimum-bend single row routing problem.

We present a three-layer over-the-cell router (ICR-3) for the standard cell design style based on a new cell model which assumes that terminals are located in the center of the cells in layer M2. This model is similar to the one currently being developed for three-layer cell libraries in industry. We have implemented ICR-3 in C on a SUN SPARCstation 1+ and tested it on several benchmarks including PRIMARY I and PRIMARY II from MCNC. We show that ICR-3 produces results which are better (on the average) by 58% as compared to a two layer over-the-cell (2OTC) router and 47% as compared to a conventional three layer channel (3CRP) router. (Abstract shortened with permission of author.)