Method and apparatus for regenerating sampling frequency and then quickly locking signals accordingly

An apparatus for receiving a signal, comprising:

• a buffering unit, receiving a plurality of data according to a symbol clock signal, reading out the plurality of data according to a first clock signal and generating a water level, wherein the water level is a data amount temporarily stored in the buffering unit;
• a clock generating unit, receiving a control signal and a second clock signal to generate a third clock signal;
• a judging unit, receiving the water level and generating the control signal according to the water level, so as to control a generating speed of the third sampling clock signal of the clock generating unit;
• a frequency detector, determining a sampling frequency of the plurality of data according to a data amount of the plurality of data during a unit time period or parameter values of the plurality of data;
• and
• a clock generator, dividing the third clock signal by a dividing value or multiplying the third clock signal by a multiplying value, so as to obtain the first clock signal and to influence the water level.