A Unified Approach to Multilayer Over-the-Cell Routing

Several Over-the-Cell (OTC) routing algorithms have been proposed for two and three layer processes. All the existing OTC routers can be used only on the cell models for which they were developed for. In this paper, we develop a unified approach to multi-layer routing, motivated by over-the-cell routing, which can be used for full-custom layouts. Our approach can also be directly applied to standard cell layouts, irrespective of the cell model used in the design. Our router has been implemented in C and tested on industrial benchmarks, such as PRIMARY I and PRIMARY II, for which it obtained channel-less layouts.