IEEE TRANSACTIONS ON COMPUTER AIDED DESIGN VOL XX NO Y MONTH Pattern Routing Use and Theory for Increasing Predictability and Avoiding Coupling

Deep sub micron e ects along with increas ing interconnect densities have increased the complexity of the routing problem Whereas previously we could fo cus on minimizing wirelength we must now consider a vari ety of objectives during routing For example an increased amount of timing restrictions means that we must minimize interconnect delay But interconnect delay is no longer simply related to wirelength Coupling capacitance has be come a dominant component of delay due to the shrinking of device sizes Regardless the most important objective is producing a routable circuit Unfortunately this often con icts with minimizing interconnect delay as minimum delay routes create congested areas for which an exact routing cannot be realized without violating design rules In this work we use the concept of pattern routing to develop al gorithms that guide the router to a solution that minimizes interconnect delay by considering both coupling and wire length without damaging the routability of the circuit The paper is divided into two parts The rst part demon strates that pattern routing can be used without a ecting the routability of the circuit We propose two schemes to choose a set of nets to pattern route Using these schemes we show that the routability is not hindered The second part builds on the previous part by presenting a framework for coupling reduction using pattern routing We develop theory and algorithms relating pattern routing and cou pling Additionally we give suggestions on how to extend our theory and use our algorithms for both global and de tailed routing