Conflict-free channel definition in building-block layout

To apply a standard channel router for the wiring between the blocks in a building-block layout, channels have to be defined and ordered. The ordering consists of determining a sequence for routing the channels. A conflict-free sequence exists only when the layout is sliceable. An algorithm that, on the basis of local preferences, finds the optimal slicing of a sliceable layout in polynomial time and space complexity is presented. The preferences are derived from data generated by a global routing routing that thus precedes the channel definition and ordering. Also included is a heuristic technique for modifying a nonsliceable placement so that a sliceable layout is obtained