A dynamically tracking clock distribution chip with skew control

A novel single-chip clock distribution circuit is described. This circuit is a self-calibrating synchronization system that receives a periodic, digital clock signal as a reference and generates multiple system clock signals that dynamically track and are synchronized to the reference clock across temperature, voltage, and process variations. This chip is used as an integral part of the clock distribution for a fault-tolerant computer system. Results from ATE and bench testing of this clock chip are presented. The edge rate, granularity, pin-to-pin skew, ASIC to nonASIC delay line, and clock jitter characteristics are verified to exceed collectively the specifications of commercially available products