VLSI Routing in Multiple Layers using Grid based Routing Algorithms

Aim of this paper is to describe a multi-layer grid routing algorithm which gives a better result over the existing algorithms. Given a multilayer grid routing area, considered the global routing problem of selecting a maximum set of nets, such that every net can be routed entirely in one of the given layers without violating the physical capacity constraints. The contribution of this paper is of threefold. First, we formulate the problem as an integer linear program (ILP). Second, we write an algorithm which proposed identical routing layers for each net using global routing . Our algorithm gives results which are guaranteed to be within a certain range of the global optimal solution and runs in polynomial-time. Finally we demonstrate that the complexity of our algorithm can be significantly reduced in the worst case prediction.