Mediatek Corporation

Mediatek Incorporation

Chao-Long Tsai

Jyh-Shin Pan

Chi-Kwong Ho

Hong-Ching Chen

Chun-Yu Lin

Li-Chun Tu

Andrew C Chang

Jin-Bin Yang

Jin-Chuan Hsu

Szu-Shan Lo

Chang-long Wu

Yao-Jen Liang

Ping-Hsing Lu

Chun-Chieh Shih

A testing system includes an integrated circuit having an analog design under test and a processor; an digital-to-analog converter (DAC), coupled to the analog design under test and the processor, for converting a digital testing sequence output of the processor into an analog testing sequence fed into the analog design under test; a analog-to-digital converter (ADC), coupled to the analog design under test and the processor, for converting an analog testing response of the analog design under test into a digital testing response fed into the processor; and an external tester, coupled to the processor of the integrated circuit, for sequentially outputting a program sequence to the processor; wherein the processor executes the program sequence without un-predictable conditional jump to get a testing result of the testing system and then outputs the testing result to the external tester.

Testing system and related testing method for an analog design under test

A recording method and drive for optical storage media. The method inserts or replaces a special pattern in a recording EFM signal before the recording process is interrupted. Therefore, the special pattern is recorded either before or on the interrupted position. The starting position of the succeeding recording process is located by searching for the special pattern.

Recording method and drive for optical storage media

A link writing method for a recordable or rewritable compact disk includes recording a writing interruption address and enabling a succeeding writing process after the writing interruption. Enabling a succeeding writing process includes searching the linking area and enabling a start writing signal and activating a laser power. The method can link a succeeding writing area with a previously written interrupted area with sufficient accuracy to allow the data frame to be successfully processed by error correction within the host drive. The linking area may be positioned by counting the values of the interrupted block, the interrupted data frame, and the interrupted bit count or by detecting a blank area. Other techniques for positioning the linking area include detecting an unwritten area having a length greater than a maximum or writing a characteristic pattern after an interruption.

Link writing method for a recordable or rewritable compact disk and drive for using the method

A system and method of switching the control modes of spindle motor are described. The switch system comprises a first control module, a second control module and a switch controller. The first control module electrically coupled to the spindle motor and the OPU controls the spindle motor to be operated in a present mode. The second control module is electrically coupled to the spindle motor to control the spindle motor to be operated in the transition mode between the present mode and the target mode. The switch controller electrically coupled to the first control module, the second control module and the spindle motor receives a present feedback signal associated with the rotation of spindle motor to generate a first switch signal. Furthermore, the switch controller receives a target indicative signal associated with the information on the optical storage medium to generate a second switch signal. The switch controller then switches the control mode of the spindle motor from the present mode to the transition mode in response to the first switch signal, and the switch controller switches the control mode of the spindle motor from the transition mode to the target mode in response to the second switch signal.

System and method for switching control modes of spindle motor

The invention advantageously provides an apparatus and method for recovering clock signals extracted from prerecorded wobbled grooves formed in an optical storage medium such as a compact disk (CD), mini disk (MD) or digital video disk (DVD). A preferred embodiment of the method according to the invention primarily comprises the steps of extracting a series of wobble signals from the prerecorded information, demodulating the wobble signals for generating a series of demodulated clock signals, detecting a period for the clock signals, dividing each of the clock signals for acquiring a series of synchronization frames, generating compensating phases, and respectively adjusting the synchronization frames with the compensating phases for generating a series of phase compensated frames.

Apparatus and method for recovering clock signal extracted from prerecorded information in optical storage devices

An ATIP (absolute time in pre-groove) bit data generator free from an uneven duty cycle. The ATIP bit data generator includes an analog processor, a high-frequency clock generator, a first decoder, a sync pattern detector, and a second decoder. The analog processor receives a signal generated from an optical pickup, and further processes the signal to generate an ATIP FM signal. The high-frequency clock generator provides a high-frequency clock using the ATIP FM signal as a reference signal. The first decoder receives the ATIP FM signal and the high-frequency clock and generates bi-phase data. The sync pattern detector receives the bi-phase data and the high-frequency clock, and generates a sync indication signal. The second decoder counts the pulse number of the high-frequency clock for each counting cycle, and the counting cycle includes a plurality of half periods of the ATIP FM signal. When the pulse number is smaller than a lower threshold value or greater than a upper threshold value, the second decoder outputs ATIP bit data with a first level. When the pulse number is between the lower threshold value and the upper threshold value, the second decoder outputs ATIP bit data with a second level.

ATIP bit data generator and method for generating ATIP bit data in optical discs

A circuit in an optical read/write device for protecting synchronizing patterns is proposed. The protection circuit utilizes a clock with constant frequency as a reference clock. The circuit for protecting synchronizing patterns of this present invention includes a SYNC detector, a frame period counter, a valid-frame-period judgment unit, a frame period memory, a window generator, a real SYNC judgment unit, a SYNC lock judgment unit, and a SYNC signal generator. The circuit counts the pulse number of a reference clock with constant frequency for each frame to get a constant frame period. Then, the circuit can correctly interpolate the lost frame SYNC signal immediately by counting the reference clock, when the disk is defected.

Circuit for protecting synchronizing patterns

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 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

Chao-Long Tsai