A Switchbox Router with Obstacle Avoidance

Detour is the channel router used by the Magic layout system. Based on Rivest and Fiduccia\´s "greedy" channel router, Detour is capable of routing switchboxes and channels containing obstacles such as preexisting wiring. It jogs nets around multi-layer obstacles such as contacts, and routes over single-layer obstacles. If there are no obstacles, results are comparable to other good channel routers. Detour thus combines the effectiveness of traditional channel routers with the flexibility of net-at-a-time routers.