Integrated circuit power and ground routing

摘要

An integrated circuit includes a plurality of blocks of cells, and a plurality of layers with conductors for signal and power routing. Power and ground connections for individual cells are supplied by power and ground conductors in a first layer of conductors at the cell level. Power and ground conductors at the block level are supplied by power and ground conductors at the top level of the layers which are connected to the first layer power and ground conductors by stacked vias. Intervening layers of conductors can be used for signal routing. This routing technique improves circuit density as compared to prior techniques where the block level power and ground conductors were in a second, lower level of conductors instead of a top level. A layout method is also disclosed in which the conductors for signal routing are defined in dependence on the placement of the block level power and ground conductors.