A Fast Multila er General Area Router for h C M Designs

The objective of this research is to develop an efficient multilayer general area router as an alternative to the three-dimensional (30) maze router for solving the multilayer MCM routing problem. Our router, named SLICE, is independent of net ordering, requires much shorter computation time, and uses fewer vias. A key step in our router is to compute a maximum non-crossing bipartite matching, which is solved optimally in 0 (nlogn) time where n is the number of possible connections. We tested our router on a number of examples, including two MCM designs from MCC. The total wirelength used by SLICE is only a few percent away from the optimal. Compared with a 3 0 maze router, SLICE is four times faster and uses 28% fewer vias. A more important feature is that SLICE works on only a "thin slice" of the two-layer routing grids at a time, while a 3 0 maze router works on the entire three dimensional routing grid. Therefore, SLICE can successfully produce solutions for large MCM routing examples where 30 maze routers fail due to insyffrcient memory.