Hybrid clock synchronization

Abstract

In one embodiment, a processing system includes an interface controller to receive a data signal from a remote link partner over a link, and recover a clock signal from the received data signal, frequency generation circuitry to receive the recovered clock signal, and output a local clock signal responsively to the received recovered clock signal, wherein the interface controller is configured to drive a transmit symbol rate responsively to the local clock signal, and a digital control loop including the interface controller and the frequency generation circuitry, wherein the interface controller is configured to identify a clock drift, generate a digital control signal responsively to the clock drift, and send the digital control signal to the frequency generation circuitry, which is configured to adjust a frequency of the local clock signal responsively to the digital control signal in order to reduce the clock drift.