The routing of bus structures on a PCB has always required a manual process to achieve the maximum densities and esthetic look. Also, the communication of the ideal bus topologies (form, layers, nets) has always been done by paper. Mentor Graphics has developed revolutionary technology that enables bus structure topologies to be planned as an automated part of the design process, captured in the design database and then carried on to the physical design process where an auto-router can efficiently route the buses. The result is a process that combines the expertise of an experienced designer with the speed of auto-routing resulting in significant productivity and design cycle time improvements.