Self-reforming routing for stochastic search in VLSI interconnection layout

Given a route which connects terminals on a one-layer routing area (Steiner tree), flip is a procedure that makes a current route change its configuration within its peripheral domain. A flip reforms a route by replacing one of its edges with a minimal detour. A route can flip one nearby obstacle. If the obstacle is another route, a more organized operation, called the dual flip, is applied to a pair of routes. The idea is enhanced to 2-layer hv-routing. The performance of flip and dual flip was tested in simulated annealing which reforms a route or a set of routes with respect to the evaluation function of multiple objectives. Some unique and satisfiable results were observed.