BLR: The Bus-line Router

A now routing algorithm based on the principle of the 'bus-line router' design is presented. The algorithm has the advantages of both maze-router and channel router that are small routing areas, high routibility, and high routing speed. The switch box problem is avoided. The basic approaches of the algorithm are using minimum bus lines to get small routing areas, and choosing the optimal distribution of terminals to increase the probability of the success of close routing. Both close routing and open routing methods are described. The complete CAD layout package, which includes layout input, global router, and detail router by using the bus-line router algorithm, has been implemented in C, on SUN workstation at San Jose State University.