Patent ID: 7890788

Claim:
In a system having at least two devices in communication with each other, wherein a first device and a second device are coupled by a data transfer link, a method for reducing a phase offset of a signal received at the first device, comprising: at the first device, receiving a first received signal at the first device transmitted from the second device over the data transfer link; measuring the phase offset between the first received signal and a clock signal from a clock source in the first device to form a first phase offset; generating a control symbol based on the first phase offset; inserting the control symbol in a first transmit signal; transmitting the first transmit signal from the first device to the second device over the data transfer link; at the second device, receiving the first transmit signal to form a second received signal, wherein the second received signal contains the control symbol; applying a phase lock loop to the second received signal by to form a recovered clock signal; extracting the control symbol from the second received signal; applying a phase shift to a second transmit signal in accordance with the control symbol and the recovered clock signal, wherein the second transmit signal has a compensated phase; transmitting the second transmit signal from the second device to the first device over the data transfer link; and at the first device, receiving the second transmit signal at the first device to form a compensated received signal having a second phase offset that is smaller than the first phase offset of the first received signal.