Sizing of clock distribution networks for high performance CPU chips

In a high performance microprocessor such as Digital's 30O MHz Alpha 21164, the distribution of a high quality clock signal to all regions of the device is achieved using a complex grid with multiple drivers. The large capacitance of this distribution grid together with the high clock frequency results in substantial power dissipation in the chip. In this paper, we describe techniques to size the interconnect segments (thus reducing their capacitance) of the distribution network while meeting certain design goals. These techniques place no restrictions on the topology of the network being sized, and have been successfully used on very large examples.