Abstract
A linear time algorithm for routing over the cells is presented. The algorithm tries to reduce maximum channel density by routing some connections over the cells. The algorithm first defines a new scheme for channel representation and formulates the problem based on an intersection graph derived from the new scheme. Then, a feasible independent set of the intersection graph is found for routing some subnets over the cells. The algorithm is implemented and evaluated with several well known benchmarks. In comparison with previous research, our results are satisfactory, and the algorithm takes substantially less CPU time than those of previous works. For Deutsch's difficult example, the previous algorithms take about 29.25 seconds on an average but our new algorithm needs only 5.6 seconds.