Rambus Inc.
Phase Control Block for Managing Multiple Clock Domains in Systems with Frequency Offsets

Abstract:

A circuit for performing clock recovery according to a received digital signal. The circuit includes at least an edge sampler and a data sampler for sampling the digital signal, and a clock signal supply circuit. The clock signal supply circuit provides edge clock and data clock signals offset in phase from one another to the respective clock inputs of the edge sampler and the data sampler. A digital phase detector determines if the data clock is early, late or synchronized with respect to data value transitions in the digital signal, and based on that determination provides a phase adjustment signal to the clock signal supply circuit, which is operable to vary phases of the data and edge clock signals accordingly.