Abstract: A method applied to an optical disc drive for calculating an error detection code corresponding to a data sector is disclosed. The data sector includes a plurality of bytes arranged in a matrix having N lines along a first direction and M lines along a second direction perpendicular to the first direction. The method includes: along the first direction, calculating error detection codes corresponding to M bytes located at each of the N lines, wherein for each of the N lines, only bytes having error bits affect an error detection code for the line; adjusting an error detection code of each of the N lines according to a displacement between each of the N lines and a last line of the N lines; and then determining the error detection code of the data sector by summing up the displacement-adjusted error detection code of each of the N lines.

Abstract: A phase-locked loop (PLL) device is disclosed. The PLL device includes an interpolator receiving and processing an input signal by an interpolation operation in response to an interpolation timing value to obtain an output signal, a timing error detector in communication with the interpolator for detecting a timing error value of the output signal, a loop filter in communication with the timing error detector for outputting the interpolation timing value to the interpolator in response to the timing error value, and a lock controller in communication with the loop filter for adjusting the interpolation timing value according to a timing quality of the output signal, and providing the adjusted interpolation timing value for the interpolator. A signal generation method for use in the data pick-up device with the aid of the digital phase-locked loop (PLL) device is also disclosed.

Abstract: Method and apparatus for use in an optical disk tilt servo system of an optical disk drive. The tilt servo system is for adjusting an angle between a surface of an optical disk and a pick-up head of the optical disk drive. The method includes: measuring focusing results of the optical disk at multiple locations and estimating tilt angles, i.e. deviation from the horizontal, of the surface of the optical disk according to a physical model that reflects that the optical disk has different tilt angles at different locations. The tilt servo system is calibrated accordingly.

Abstract: An apparatus for generating a wobble clock includes an operation circuit for receiving a wobble signal and counting cycles of an oscillating signal during a cycle of the wobble signal to derive a cycle value and for comparing the cycle value with a preset cycle value to output a first protection signal, and a phase-locked loop circuit connected to the operation circuit for receiving the wobble signal, the wobble clock and the first protection signal, and determining whether the wobble clock is to be synchronized with the wobble signal according to the first protection signal.

Abstract: A method of identifying ADIP information through counting identical bits and different bits includes generating a wobble clock according to a wobble signal, generating a calculation result according to the wobble signal and the wobble clock, sampling the calculation result to generate a sampling signal and comparing each bit of the sampling signal with each bit of a bit stream containing an ADIP data, counting different bits corresponding to a predetermined logic value for generating a first bit count, and counting identical bits for generating a second bit count, and determining whether the calculation result corresponds to the ADIP data according to the first bit count and the second bit count.

Abstract: In a Viterbi decoder, a branch metric calculating operation of a series of received input data is performed according to different sets of target levels to realize a plurality of branch metric values, wherein said target level sets are not identical. Accumulative operations of the branch metric values are performed, respectively, and the plurality of accumulated values are compared in groups. A plurality of control signals and a plurality of least accumulated values are outputted according comparing results of the accumulated values. The least accumulated values are received and stored, and then fed back for next accumulation operations. A plurality of possible output-data state transition tracks are recoded in response to the control signals. The output data are determined according to the least accumulated values and output-data state transition tracks.

Abstract: When performing OPC, data including a plurality of first sequences and second sequences with specified contents are written onto the optical disk. A read result corresponding to the written data is then read. The read result is high-pass filtered such that effects corresponding to the second sequences are contained in a portion of the read result corresponding to the first sequences. Since the first sequences have specified contents, the portion of the read result corresponding to the first sequences are detected, and the beta-parameter is evaluated only according to the portion of the read result corresponding to the first sequences.

Abstract: A method and the related apparatus for performing optimal power control of an optical disk drive includes reading a write-in data from an optical disk and generating a corresponding read result after the write-in data is written onto the optical disk with the default power, and accumulating a beta parameter according to a portion of the filtered read result whose level is higher than a first level and lower than a second level. The first level is substantially higher than the second level.

Abstract: A focus control system for an optical pickup head is provided. The optical head generates an electronic signal in response to an optical signal. The focus control system comprises a focusing error signal generator, a focus control signal generator and an actuator. The focus control signal generator is electrically connected to the focusing error signal generator, and includes a first, a second and a third compensators with a first, a second and a third gains, respectively, for generating a focus control signal with one of the first, second and third gains in response to the focusing error signal according to a corresponding one of a first, a second and a third operating modes of the optical pickup head. A method for controlling movement of an optical pickup head is also provided.

Abstract: A process for computing an eccentric amount of a disk upon rotating is provided. The process includes steps of starting a servo control system of a disk drive to rotate the disk at a specified angular velocity, measuring a track crossing speed of the servo control system at a focusing point on the disk, and computing the eccentric amount of the disk according to the specified angular velocity and the track crossing speed. A process for controlling rotation of a disk loaded in a disk drive is also provided. The process includes steps of realizing an eccentric amount of the disk, and rotating the disk at an operating speed corresponding to the eccentric amount.

Abstract: A method is provided for outputting a focusing completion signal to realize a focusing condition of an optical pickup head for an optical access apparatus. The method is described as follows. A trace shift of the optical pickup head along a focusing direction is actuated in response to a focus control signal when a focus adjustment operation starts. Then, a focusing error signal and a sub-beam addition signal are generated in response to optical signals from the optical pickup head. A closed-loop enable signal is generated to enable a closed-loop control operation in response to a specified situation of the focusing error signal. The focusing completion signal is outputted when the sub-beam addition signal is at a level greater than a threshold value and when the closed-loop enable signal is generated.

Abstract: An apparatus for generating wobble clock comprises: a comparing circuit and a phase lock loop. The comparing circuit generates a combining signal according to peak values of the wobble signal and compares the output signal with a reference voltage to output a control signal. The phase lock loop drives the wobble clock to be synchronized with the wobble signal if the protection signal corresponds to a first logic level, and stops driving the wobble clock to be synchronized with the wobble signal if the protect signal corresponds to a second logic level.

Abstract: A method and related circuit for clock generation and recovery utilizes digital components exclusively. The method is used to generate a wobble clock and an absolute time in pre-groove (ATIP) clock for controlling the operation of an optical disk drive. The circuit includes a counter and a digital logic circuit and utilizes clock triggering processes.

Abstract: A method for determining a direct current (DC) level involved in an alternating current signal is provided. The alternating current signal is transmitted from an amplifier to an A/D (analog-to-digital) converter. When any of the extreme values of the alternating current signal is beyond the input range of the A/D converter, the alternating current signal is shifted to make both of the peak and bottom values located within the input range of the A/D converter. Then, the real extreme values are realized according to the shift level(s), the relative peak and bottom values realized after the shifting procedure, and the input range of the A/D converter. Finally, the DC level is determined according to the real peak and bottom values.

Abstract: A method for determining an optimum writing power of a compact disc drive includes representing the relationship between a target read-back signal parameter and writing power as a polynomial function, which is stored in a database. The optimum writing power is obtained after at least one iteration of a writing test procedure. The test procedure includes utilizing a constant writing power.

Abstract: A method and related apparatus for storing program code and optimized power calibration (OPC) data in the same non-volatile memory is provided. The method is used for accessing OPC data from an optical discrecorder. The optical disc recorder is capable of obtaining OPC data of an optical disc by executing an optimized power calibrating process so as to record data onto the optical disc. The optical disc recorder has a first memory with a program code being stored therein and a second memory. The method includes registering the program code in the second memory, and writing the OPC data of the optical disc to the first memory according to the program code registered in the second memory.

Abstract: The disclosed invention provides a tracking method of an optical storage. When proceeding with tracking, the optical pickup head can be moved constantly and the TE signal can be detected. Then differentiation of the TE signal is obtained. If the differentiation is less than 0, then the TE signal is masked; otherwise, the TE signal is not masked. Therefore, the TE Hysteresis signal can be determined by the TE signal and its differentiation. The TE Hysteresis signal of 0 represents that the laser beam is in the Pit, and then the tracking procedure is finished. Otherwise, the aforementioned steps are repeated until the end of the tracking procedure.

Abstract: A device and method for measuring the jitters of phase locked loop signals. A phase lead or phase lag relationship between an input signal and an output signal of a phase locked loop is found. According to the phase relationship and using multiplexers, a first phase difference signal and a second phase difference signal are re-routed to a subtraction unit and produces a jitter-level output signal. The jitter-level output signal represents the absolute value of the difference of pulse width between the first phase difference signal and the second phase difference signal.

Abstract: A method is proposed for accessing the memory of a de-interleaving unit. The conventional access method has the drawback of ineffective use of the memory space of the de-interleaving unit, while the proposed method uses only about half the memory space for implementation. The proposed method utilizes a specially-formulated write-operation interleaving algorithm to write data into the memory of the de-interleaving unit, and subsequently utilizes a specially-formulated read-operation de-interleaving algorithm to read data from the memory of the de-interleaving unit.

Abstract: A method for recovering a data required to have n consecutive and repetitive bits is disclosed. The data is obtained by converting a sample value sequence into a binary sequence according to a preset value and the data having n−1 consecutive first-level bits and two second-level bits immediately adjacent to two end bits of the n−1 consecutive first-level bits, respectively. The method corrects one of the two second-level bits, which has a corresponding sample value closer to the preset value than the other, into another first-level bit to obtain n consecutive first-level bits. In addition, a device for recovering a data to be decoded is also disclosed.