Mediatek Corporation

Mediatek Incorporation

Chi-Kwong Ho

Chao-Long Tsai

Jing-Hong Conan Zhan

Wen-Yi Wu

Andrew C Chang

Jin-Chuan Hsu

Chao-Lung Tsai

An adaptive frequency detector used in a phase locked loop for detecting a frequency difference between an input signal and an output clock generated from an oscillator of the phase locked loop includes: a frequency comparator for generating an up signal or a down signal according to the frequency difference between the input signal and the output clock; and a pulse controller coupled to the frequency comparator for generating a charge signal based on the up signal or generating a discharge signal based on the down signal. The pulse controller dynamically adjusts the pulse width of the charge signal or the pulse width of the discharge signal.

Adaptive frequency detector of phase locked loop

A device and method for calibrating linear velocity and track pitch for an optical disc is disclosed. The device comprises a frequency divider, a synchronous bit-clock generator, a counter and a linear velocity and track pitch calculator. The frequency divider receives a motor frequency generator (FG) pulse and generates a motor rotation period signal (FG/X). The synchronous bit-clock generator generates a high frequency bit-clock according to a reproduced signal read from disc. The bit counter counts the pulse of the bit-clock for each period of the motor rotation period signal to generate the data amount M. The linear velocity and track pitch calculator calculates the linear velocity by a linear velocity function with the information of the data amount M and the motor rotation period. Then, the linear velocity and track pitch calculator calculates the track pitch by a pitch function with the information of the data amount, radius and linear velocity at different tracks.

Device and method for calibrating linear velocity and track pitch for optical disc drive

A data slice circuit and the method thereof The data slice circuit comprises a digitizer, a finite state machine, and a digitizer parameter adjustment element. The digitizer receives an analog signal and converts to a digital signal. The finite state machine generates a state signal in response to the digital signal. The digitizer parameter adjustment element generates a parameter adjustment signal in response to the state signal from the finite state machine. The digital signal of the digitizer is adjusted in accordance with the parameter adjustment signal.

Digitization apparatus and method using a finite state machine in feedback loop

A method is provided for use on an optical disc drive, which can automatically detect the current radial position of the pickup head to thereby switch the motor operation between the CLV (constant linear velocity) mode and the CAV (constant angular velocity) mode for optimal performance of the optical disc drive. The current radial position of the pickup head is detected by using CLV and CAV position estimating means. If the current radial position of the pickup head is at a preset switching point, the mode of operation is switched from the current one to the other. Moreover, the reference signals used in the respective modes are adaptively varied so as to allow the data transfer rate of the data read operation on the optical disc to be consistent in both modes without interrupting the reading and transferring of the data from the optical disc. The method can thus allow the benefits of a high data transfer rate, short seek time, and low power consumption by the optical disc drive.

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Hsinchu, Taiwan

Chi-Kwong Ho