PHIroute: A parallel hierarchical sea-of-gates router

The routing of modern sea-of-gates circuits is a very hard to solve combinatorial problem. The use of three or more layers of metal allows for channelless designs, where area routers are used to connect the pins of a net. In this paper, we present a new router that aims at combining the good quality of the traditional global/final routing approach with the high efficiency of strictly hierarchical routers. This is achieved by reducing the routing problem until its complexity is manageable. The reduced problem is then solved hierarchically by well-known maze-running algorithms using the divide-and-conquer paradigm. In addition to the ability to handle big circuits efficiently, this approach allows the parallel solution of subproblems, yielding significant speedups even when using workstation networks