Length matching in detailed routing for analog and mixed signal circuits

• An efficient and effective routing model is presented for net detouring.
• For a given tile, different types of detouring patterns are presented.
• A⁎ algorithm with backtracking method is presented for length matching.
• Iterative rip-up and reroute is adopted to find length-matching solution.

Heterogeneous integration in modern System-On-Chips (SOCs) drives the design automation process for analog and mixed signal circuit components, where matching constraints for certain analog signals are critical for correct functionality. This paper presents a detailed routing solution for analog nets with the single-layer length matching constraint called LEMAR, i.e., a single-layer LEngth MAtching Router.LEMAR is a gridless router using a non-uniform grid routing model to ensure the length matching constraint. LEMAR has the following features: (1) an effective routing model is used for layout partitioning and wire detouring, (2) detouring patterns are presented to obtain the given detouring length, and (3) an enhanced A⁎ search algorithm along with backtracking technique is presented for finding a routing solution with the length matching constraint. Experimental results are promising.