A town planner works out the number, types, and sizes of buildings in a development project. An architect designs each building, including the arrangement of the rooms in each building. Then a builder carries out the construction according to the architect’s drawings. Electrical wiring is one of the last steps in the construction of each building. The physical design of ASICs is normally divided into system partitioning, floorplanning, placement, and routing. A microelectronic system is the town and the ASICs are the buildings. System partitioning corresponds to town planning, ASIC floorplanning is the architect’s job, placement is done by the builder, and the routing is done by the electrician. We shall design most, but not all, ASICs using these design steps.