Abstract: A method and an apparatus for controlling data access rate of an optical disc player are disclosed. The method includes steps of (1) utilizing a micro-controller to decide whether an action of an instruction of a predetermined data processing is an extraction operation or a play operation; (2) driving the spindle motor and a pick-up head to retrieve data from an optical disc at a first data access rate by the micro-controller while the action of the instruction of the predetermined data processing is an extraction operation; and (3) driving the spindle speed and the pick-up head to retrieve data from the optical disc at a second data access rate which is less than the first data access rate by the micro-controller while the action of the instruction of the predetermined data processing is a play operation.

Abstract: A method for generating error detection code is disclosed. Firstly, a first error detection code PEDC is derived by using 12-byte unknown sector data information including ID, IED, RSV and the 2048-byte main data while the main data is delivered from a host. Secondly, a second error detection code MEDC is obtained by using known 12-byte sector data information including ID, IED, RSV and the 2048-byte main data. Thereafter, the real error detection code EDC is obtained by applying an exclusive-OR operation to both the PEDC and MEDC.

Abstract: A system of sampling interface for an optical pick-up head comprises an optical pick-up head, a PMOS, a boost circuit, and a sample and hold circuit. The optical pick-up head outputs one of a reading voltage and a writing voltage. The PMOS gate receives the gate voltage and then the PMOS is turned on to pass the reading voltage to the sample and hold circuit. Moreover, the substrate of the PMOS receives a control voltage. The boost circuit is used to boost the gate voltage higher than the control voltage for turning off the PMOS and isolating the writing voltage.

Abstract: A method for controlling read power and an open-loop read control device using the same. The open-loop read control device is used in an optical disk writer and includes a memory, a DAC and an amplifier. The optical disk writer includes a pickup head device having a laser diode. When writing is disabled, the read power of the optical disk writer for reading the disk corresponds to a specific voltage. The memory stores a relationship curve and outputs a corresponding reference value corresponding to the specific voltage. The DAC converts the corresponding reference value into an analog corresponding reference value. The amplifier receives the analog corresponding reference value and outputs a read power control voltage, which controls the laser diode to generate a substantially constant read power in the write process.

Abstract: An apparatus and a method for generating ATIP data is provided. The apparatus generates ATIP data from a wobble signal of a re-writable compact disc. The apparatus includes a frequency demodulator for demodulating the wobble signal to generate an original ATIP data signal; an ATIP clock generating circuit for generating an ATIP clock signal based on the wobble signal; and a data generating circuit, coupled to the frequency demodulator and the ATIP clock generating circuit, for generating the ATIP data based on the number of measurement periods for which the original ATIP data signal is at a first logic level during one period of the ATIP clock signal. This apparatus uses this number and the bi-phase rule to precisely generate ATIP data.

Abstract: An operating current modifying device is provided for a power generating element. The power generating element generates an output power when the operating current is larger than a threshold current in the power generating element. A functional relationship is between the threshold current and the temperature of the electrical device. The operating current modifying device includes a threshold current modifying module, a power modifying module, a current compensating module, and a power control module. The threshold current modifying module receives a temperature signal from the power generating element to output a threshold current modifying signal according to the temperature signal and the functional relationship. The power modifying module receives a power feedback signal from the power generating element and a target power signal to output an operating current modifying signal.

Abstract: An encryption/decryption method and devices for protecting data in a memory device from unauthorized access is provided. First, obtaining a specific code from a memory device and then encrypting the specific code and original data for obtaining encrypted data during a write cycle. Finally, writing the encrypted data to the memory device according to an access address. The access address can be also encrypted to generate the encrypted data. The encryption level increases by this way so that the valuable information is under protection.

Abstract: The method of detecting defect signals includes: setting a default pit length range; inputting a data signal including a plurality of pits with different pit lengths; transferring the data signal into NRZ signal and counting the pit length of each pit; accumulating the number of the pits whose pit length are within the default pit length range, and accumulating the number of the pits whose pit lengths are outside the default pit length range but within the corresponding ranges; changing the logic state of a defect flag signal when one of the accumulative value reaches a corresponding threshold. The present invention also provides an apparatus for detecting defect signals.

Abstract: The present invention provides a method for detecting disk defects of a blank optical disk in a recording and reproducing system when a data-recording operation is performed. In the embodiment, an ATIP and the carrier signal of the ATIP signal, ATFM signals, are compared to obtain a difference between these two signals. A wobble defect flag signal is set if the difference keeps higher than a predetermined threshold for a predetermined time interval. On the contrary, the wobble defect flag signal is cleared if the difference keeps lower than the predetermined threshold for the predetermined time interval.

Abstract: A method is proposed for utilizing a memory of a de-interleaving unit comprising the steps of determining a size of the memory according to a maximal symbol number of a data frame, a delay value, an adjustable parameter, and a half of a total symbol number of the data frame; accessing the memory according to a write memory address determined by a first algorithm during data buffering; and accessing the memory according to a read memory address determined by a second algorithm during data retrieving. 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.

Abstract: A controlling method and device for data transmission including the steps of providing a system bus for connecting a first transmission channel and a second transmission channel with a command processor, adjusting a transmitting direction of the system bus according to a transmitting direction of the second transmission channel, and proceeding the data processing procedures of the second transmission channel, wherein parts of data processing procedures of the first transmission channel will last during a interval between the system bus adjusting the transmitting direction and the data processing procedures of the second transmission channel start on. The present invention ensure that the independence between every data caching and processing reduces the times of flushing the cached data from the data transmission channel and re-seeking through the source, shortening the transmission time, increasing facileness and improving the efficiency of the data transmission.

Abstract: An apparatus for adjusting the phase of a wobble clock including a phase adjusting circuit for receiving a wobble signal and a wobble clock to generate a phase adjusting value, and a frequency divider coupled to the phase adjusting circuit for adjusting the phase of the wobble clock according to the phase adjusting value.

Abstract: A data slicer capable of dynamically adjusting a slice level according to a wobble signal retrieved from a DVD-R/RW disc. The data slicer has a peak hold circuit for generating a first output signal according to positive peaks of the wobble signal, a bottom hold circuit for generating a second output signal according to negative peaks of the first output signal, a bias circuit for utilizing a bias voltage to raise voltage levels of the second output signal to generate the slice level, and a comparator for comparing the wobble signal with the slice level to generate corresponding square wave signal.

Abstract: A read only memory circuit for debugging and updating, the circuit includes read only memory, debug program memory, program counter, and compare and load unit. In the circuit, the compare and load unit detects instruction-read-memory-address from the program counter. If the instruction-read-memory-address is a predetermined main program address, the compare and load unit serves to transmit a debug address in the debug program memory to the program counter to update the original instruction-read-memory-address for debugging.

Abstract: A method for controlling an optical pickup head of an optical processing apparatus is provided. A first lead-lag compensator is disabled and a second lead-lag compensator is enabled when the optical pickup head switches from a following mode to a seeking mode. Then, an initial operating factor of the second lead-lag compensator is determined according to a last input value and a last output value of the first lead-lag compensator. An initial kick force of the actuator in the seeking mode is calculated by realizing the last input value and the last output value of the first lead-lag compensator immediately before the first lead-lag compensator is disabled. Finally, the optical pickup head is actuated to perform a seeking operation with the initial kick force.

Abstract: An optical storage system includes a pickup head for picking up data from a storage medium. Firstly, the maxima of a tracking error signal and runout are obtained in a calibration procedure in a close loop formed by an optical pickup head, a pre-amplifier, a compensator, a band-pass filter and a maximum detector. A calibration factor is then defined and derived by using the obtained maxima and nominal factors of a power amplifier and the optical pickup head of the optical storage system. The path formed by the series-connected band-pass filter and maximum detector is then disabled, while the calculated calibration factor is then stored in the compensator. The optical storage system may operate in a close loop formed by the optical pick head, pre-amplifier, compensator, a power amplifier under a normal operation procedure so that the optical storage system may record or read data onto/from an optical disc under the compensation provided by the calibration factor.

Abstract: An encoding method for recording gap regions or sectors having repeated data is disclosed. At least one sector is entirely encoded and stored in a memory buffer of the optical recording system. If the currently encoded are gap regions or sector having repeated data embedded in the fields of user data, only those portions affected by the modified header will be encoded to derive associated P code and Q code. The error detection code is firstly generated in the mode 1 standard when a gap region is encoded. P code is then encoded for those regions affected by the sequentially modified header and error detection code, while associated Q code is then derived according the modified header, error detection code, and P code. In the mode 2 form 1 and mode form 2 standards, only those regions affected by the sequentially modified header should be re-encoded again.

Abstract: A pre-treating circuit for accessing the disc and a method thereof, which are especially used for treating the signal waveform that violates the encoding rule of the disc information, are provided. The present invention can modulate the signal waveform that violates the encoding rule, so that the waveform is not changed during at least 3 continuous periods of the clock signal. The present invention also replaces any wrong 16-bit data which violate the encoding rule, with approximated 16-bit data before they are decoded, or receives approximated 8-bit data which correspond to the incorrect 16-bit data, by directly referring to a table. Therefore, the subsequent decoding module can acquire more data for continuous processing, so as to improve the data reading reliability and to prevent the “picky disc” or “disc error reading” problem from happening.

Abstract: A power control circuit for an optical information recording device is disclosed. A power sampling signal from a photodiode is transmitted to a peal envelope acquiring circuit and a bottom envelope acquiring circuit and then sampled and held, which is fed-back to a laser diode driving circuit. The laser diode driving circuit alters a driving signal emitted to the laser diode according to the fed-back signal to adjust the power of the optical signal emitted from the laser diode. Therefore, cost is reduced and the power control circuit is particularly suitable for high-speed recordable optical disk drive.

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.