Signal flow driven analog IC router

This paper describes a new system for the routing of analog integrated circuits, signal flow driven routing system. The routing system classifies the nets into critical nets and general nets according to their characteristics of the signal flow. Therefore it is much easier to route the nets under those analog constraints, such as symmetry, matching, parasitics and cross-talk minimization, at the same time. Resource estimation and layer assignment are applied before multi-layer routing. A* algorithm from the field of AI is introduced into the critical net routing and maze algorithm is adopted in the general net routing. Rip-up rerouting is integrated to obtain the better routing result and to ensure the routing completion rate. Experimental results show that the algorithm can get a good result in nets routing and satisfy performance and constraints of analog circuits to some extend.