Circuitry for distributing clock signals (e.g., reference clock signals) among a plurality of blocks of circuitry. Each block may include reference clock source circuitry and reference clock utilization circuitry. Each block also preferably includes an identical or substantially identical module of clock signal distribution circuitry that can (1) accept a signal from the source circuitry in that block, (2) apply any of several clock signals to the utilization circuitry in that block, and (3) connect to the similar module(s) of one or more adjacent blocks.