High performance clock distribution for CMOS ASICs

Abstract

An effective clock distribution system is presented for high performance CMOS standard cell designs. The system can achieve clock skew of less than 500 ps with phase delay under 4 ns. The system is flexible, multitiered, netlist-specific, compatible with commercial routers, and accurately modeled. Clock tree structure, interconnect constraints, buffer design methodology, netlist-driven placement, localized clock assignment, simulated annealing, layout reintegration, and simulation modeling are discussed