WOBBLE SIGNAL SYNTHESIZER AND METHOD FOR GENERATING SYNTHESIZED WOBBLE SIGNAL SYNCHRONIZED WITH PHYSICAL WOBBLE SIGNAL THROUGH COMPARING PHASES OF BOTH LAND PRE-PIT SIGNAL AND SYNTHESIZED WOBBLE SIGNAL WITH A REFERENCE CLOCK

摘要

A wobble signal synthesizer for generating a synthesized wobble signal synchronized with physical wobble signal is disclosed. The wobble signal synthesizer includes a variable-period signal generating module for generating the synthesized wobble signal; a first period calculating module, electrically coupled to the variable-period signal generating module, for calculating the number of periods of a second reference clock in a certain period of the synthesized wobble signal; a second period calculating module for calculating the number of periods of the second reference clock in a certain wobble period at a disc rotation speed; a comparison module, electrically coupled to the variable-period signal generating module, the first period calculating module, and the second period calculating module, for outputting the period error value; and a phase alignment module, electrically coupled to the variable-period signal generating module, for determining the phase error value.