Physical interface and associated signal processing method for clock domain transfer of quarter-rate data

The present invention provides a physical layer and associated signal processing method for clock domain transfer of quarter-rate data. In the embodiments of the present invention, the quarter-rate data is processed by many sampling circuits by using a first clock signal, a second clock signal and a third clock signal, and phases of these clock signals are aligned by using a training mechanism to that the clock signals have better timing margins.