8260results about "Digital signal error detection/correction" patented technology

The present invention relates to a system for (1) protecting the transmission of packet streams between a host computer and one or more client computers, and (2) upon reception, (a) reconstructing any outage damage caused during the transmission to the packet streams, and (b) digitally recording the reconstructed packet streams to a file. The present invention also relates to a method for dynamically generating a file index table as the packet stream is being digitally recorded.

Techniques for detecting and correcting burst errors in data bytes formed in a two-level block code structure. A second level decoder uses block level check bytes to detect columns in a two-level block code structure that contain error bytes. The second level decoder generates erasure pointers that identify columns in the two-level block structure effected by burst errors. A first level decoder then uses codeword check bytes to correct all of the bytes in the columns identified by the erasure pointers. The first level decoder is freed to use all of the codeword check bytes only for error byte value calculations. The first level decoder does not need to use any of the codeword check bytes for error location calculations, because the erasure pointers generated by the second level decoder provide all of the necessary error locations. This techniques doubles the error correction capability of the first level decoder.

A method for low-density parity-check (LDPC) encoding of data comprises defining a first M×N parity check matrix; generating, based on the first parity check matrix, a second parity check matrix having an M×M triangular sub-matrix; and, mapping the data into an LDPC code word based on the second parity check matrix. The method is particularly useful for data communications applications, but may also be employed in other applications such as, for example, data storage.

A recording apparatus includes: a type detecting section that detects a type of storage medium; an erase-block size detecting section that detects an erase-block size of the storage medium; a recording section that records desired data to a data area in the storage medium and records management information of the data area to a management area in the storage medium; and a control section that controls the recording section by issuing a command to the recording section, on the basis of results of the detection. Each time a certain amount of data is recorded to the data area, the control section updates the management information in accordance with the recording, and when the storage medium is a storage medium in which recorded data is updated for each erase-block size, the control section increases the certain amount of data according to an increase in the erase-block size.

A disc having an updatable defect management area used by an apparatus for managing defects on the disc, the disc including a user data area which includes user data, a spare area that is a substitute area for a defect existing in the user data area, and an area in which are recorded an address of data that is last recorded in the user data area and an address of a replacement data recorded in the spare area. Accordingly, the disc defect management method and apparatus are applicable to a recordable disc such as a write-once disc while effectively using a defect management area of the disc.

A media player may occasionally be unable to play or continue to play a particular item of media. When that occurs, the media player outputs an error indication that is related to the type of media that the problem media item is representative of. For example, if the problem item is a movie, then the media player may display an error indication having the appearance of broken movie film. If the problem media item is music, then the media player may display an error indication having the appearance of a broken compact disc (“CD”). Thus whatever the type of media that is not playing, the media player outputs an error indication that is appropriate for that type of media. The error indications output by the player are therefore context-based or media-appropriate.

An information storing disk including at least one system stream stored thereon. The at least one system stream includes a silent cell for defining a silent period and an audio cell for defining audio data to be reproduced after the silent period. The silent period is a period to be silent, which is from when one system stream to be reproduced among at least one system stream is determined until reproduction of an audio cell included in the one system stream is started.

A failure predicting unit predicts a failure in a hard disk device that forms a disk array. A data transferring unit transfers data from a failure-predicted hard disk device for which the failure is predicted by the failure predicting unit to a spare disk. A data deleting unit deletes the data from the failure-predicted hard disk device after the data transferring unit completes transferring the data.

A disk drive is disclosed wherein a write command is verified according to a rotational position optimization (RPO) algorithm rather than immediately after the write command to better optimize drive performance relative to mechanical latencies.

A multi-layered information recording medium including a plurality of recording layers, the multi-layered information recording medium comprising: a user data area for recording user data; and a plurality of spare areas including at least one replacement region, wherein when the user data area includes at least one defect region, the at least one replacement region may be used in place of the at least one defect region, wherein a first spare area of the plurality of spare areas is positioned so as to be contiguous to a first user data area of a first recording layer, a second spare area of the plurality of spare areas is positioned so as to be contiguous to a second user data area of a second recording layer, and the first spare area and the second spare area are positioned approximately at the same radial position on the multi-layered information recording medium.

In an information recording medium for recording and reproducing data thereon on a sector-by-sector basis, the recorded data being managed as at least one file by using a file structure, the file structure includes unused space management information for identifying a used region and an unused region. At least one defective region is registered as an unused region in the unused space management information, the at least one defective region being a region on the information recording medium which is incapable of proper reproduction of the recorded data.

A storage system comprises a storage array controller and a storage array, which includes multiple disk drives and disk drive controllers. The storage array controller issues scrubbing operation commands to one or more of the disk drive controllers. In response, each disk drive controller that receives a scrubbing operation command reads data from within a data range from at least one of the disk drives, calculates a new checksum for the data, and compares the new checksum to a preexisting checksum for the data. If the new checksum doesn't equal the preexisting checksum, the data within the data range is determined to be erroneous.

A disk drive includes a disk defining a multiplicity of sectors. A method of operating the disk drive includes a step of providing a firmware-controlled state machine which can be in any of a plurality of states including an off-line in-progress state. While the state machine is in the off-line in progress state, the drive performs a firmware-controlled scan of the multiplicity of sectors. While performing the firmware-controlled scan, the drive identifies and repairs a marginal sector.

A method for low-density parity-check (LDPC) encoding of data comprises defining a first MxN parity check matrix; generating, based on the first parity check matrix, a second parity check matrix having an MxM triangular sub-matrix; and, mapping the data into an LDPC code word based on the second parity check matrix. The method is particularly useful for data communications applications, but may also be employed in other applications such as, for example, data storage.

A disk drive is disclosed wherein if multiple retries beyond a threshold are required to recover a data sector during a normal read operation, the data sector is added to a marginal sector list. During an off-line scan, the data sectors in the marginal sector list are verified. If the verification of a data sector fails, the data sector is relocated.

Various embodiments of the present invention provide systems and methods for data processing. For example, a variable iteration data processing system is disclosed that includes at least a first detector, a second detector, a decoder, and a queuing buffer. The first detector is operable to perform a data detection on an input data set at a first time. The decoder receives a derivation of an output from the first detector and performs a decoding process. Where the decoding process fails to converge, the decoder output is passed to the second detector for a subsequent detection and decoding process at a second time.

A computer program embodied on a computer readable storage medium is disclosed for dependently adjusting at least three operating levels of a disk drive by dependently adjusting a plurality of disk drive parameters. The computer program receives control input from one or more sources, such as an end user, an environmental sensor, or the disk drive, wherein the control input for adjusting at least three operating levels of the disk drive in a dependent manner. In response to the control input, the computer program adjusts a plurality of parameter settings in the disk drive in a dependent manner. In one embodiment, the operating levels dependently adjusted by the control input comprise a performance level, a capacity level and a robustness level.

This invention provides a method for creating / writing defect management information of an information recording medium and an apparatus and optical disc based on the method. In the present invention, it depends on the type of data to be reproduced whether or not defective sectors which are detected during reproduction operation are replaced with non-defective sectors. If read-out errors are detected in reproducing non-audio / video data, linear replacement algorithm is applied to the corresponding defective sectors. On the other hand, in case of audio / video data, location information of the corresponding defective sectors is just kept without any sector replacement. Therefore, this invention enables to reproduce audio / video data in real-time regardless of the presence of defective sectors and to avoid writing data to the defective sectors when new data is overwritten to the information recording medium.

An information recording medium according to an aspect of this invention includes a data area (A2) for recording user data and an address area (DMA address area) for recording address data that indicates the position of a defect management area that manages a defect present in the data area.

It is an object of the present invention to improve reliability of defect management. By providing a plurality of management data areas each including a defect management area typically in a lead-in zone of a disc inner-side region enclosed by a circumference having a predetermined radius on a disc-shaped recording medium, reliability of the defect management can be obtained. In addition, by placing a plurality of the defect management areas (information areas Info1 and Info2) at locations, which are separated from each other in the radial direction of the disc-shaped recording medium, sandwiching a recording / reproduction condition adjustment area OPC having a relatively large size, the reliability of the defect management areas can be further improved. Furthermore, by providing each of the defect management areas with a plurality of recording areas, which include a currently used recording area for recording defect management information and spare recording areas each usable as a substitute for the currently used recording area, the currently used recording area can be replaced with one of the spare recording areas in accordance with an update count of the currently used recording area or error status of this currently used recording area.

A method is disclosed for performing a defect scan for a disk drive. Data is recorded on a first data area of a disk substantially free from defects and on a second data area of the disk substantially affected by at least one defect. A defect scan parameter is initialized with an initial setting. The first data area is read to determine a first defect threshold, and the second data area is read to determine a second defect threshold. A margin is saved representing a difference between the first and second defect thresholds. The setting for the defect scan parameter is adjusted, and the elements of reading the first and second data areas and saving a corresponding margin are repeated at least once. A setting is then selected for the defect scan parameter in response to the saved margins.

A disk drive is disclosed which links disk commands that access near sequential data sectors. The linked and non-linked disk commands are inserted into an input / output queue and selected for execution according to a rotational position optimization (RPO) algorithm. If an error occurs while executing a linked disk command, the disk commands are unlinked and at least one of the unlinked disk commands is executed. The residual unlinked disk commands are inserted back into the input / output queue for later execution in an order determined by the RPO algorithm.

A disk drive is disclosed comprising a disk having a plurality of data tracks, wherein each data track comprises a plurality of data sectors, and a head is actuated over the disk. A suspect sector list (SSL) stores a plurality of SSL entries, wherein each SSL entry identifies at least one suspect data sector. The disk drive further comprises a disk controller for executing an access command received from a host computer to access at least one of the data sectors. If an error is detected while executing the access command, the disk controller generates an SSL entry having a priority level selected from at least three priority levels and adds the SSL entry to the SSL. A verification operation is executed for each suspect data sector identified by each SSL entry, wherein the SSL entries are processed relative to the priority level assigned to each SSL entry.

A recording medium that is a write-once recording medium with data rewritability, thereby increasing the usability of the write-once recording medium, is provided. In a write-once recording medium, a main data area has a normal record and playback sub-area (a user data section), a rewriting replacement sub-area (an OSA), and a replacement management sub-area (an ISA). In response to a request to write data to an address at which data has been recorded, the rewritten data is recorded in the rewriting replacement sub-area (the OSA), and replacement management information that associates the original address with the address in the rewriting replacement sub-area is recorded into the replacement management sub-area (the ISA). Thus, data rewriting is achieved. Accordingly, a write-once recording medium can be substantially used as a data rewritable recording medium.

A method and apparatus for recording on an optical recording medium, including the recording of management information, are described as a standard for the write-once Blu-ray disc. The management information is recorded in a management area of the disc, such as a temporary defect management area (TDMA), and includes record status information and update information. The record status information is a space bitmap (SBM) indicating whether a recording operation has been performed for a predetermined area of the disc, and the update information is SBM update information indicating whether the record status information is to be continuously managed. The SBM update information controls the state of an SBM-on / off function for each of a plurality of recording areas and may be in the form of either start position information and length information corresponding to the respective areas or an SBM update flag. The SBM update information is recorded in the TDMA and is stored in a memory of an optical disc recording / reproducing device for use during recording and reproducing operations. At the time of recording in the predetermined area, an SBM-on state enables a logical overwriting operation to be performed as necessary.

The latest management data recorded in a recording medium is read. Then, it is judged whether the fault is in this latest management data or not. When it is judged the fault is not in this latest management data, a data size of user data under the management of this latest management data is compared with a data size of the user data recorded actually in the recording medium. In the judgment explained above, when the latest management data cannot be read, when it is judged the fault is in the latest management data or when it is judged a data size of user data under the management of the latest management data is not identical to a data size of the user data recorded actually in the recording medium, management data can be updated by analyzing the user data recorded in the recording medium. Thereby, there is provided a repair technique for the recorded data in response to an accidental shut-off condition of power supply in a data recording apparatus for recording user data and management data used for management of such user data to the recording medium.

Errors in data retrieved from a storage medium are verified by retrieving a plurality of data blocks from the storage medium. A data set having data from multiple data blocks is selected, where the data set includes a plurality of rows corresponding to the data bocks and a row has data from a data block corresponding to the row. One or more error correction codes (ECCs) are retrieved from the storage medium, where the one or more ECCs correspond to the data set. A plurality of check sums are retrieved from the storage medium, where a check sum corresponds to a data block. Data blocks retrieved from the storage medium having errors are identified using the check sums corresponding to the data blocks. When the number of data blocks identified as having errors is greater than the number of ECCs for the data set, a first set of rows in the data set corresponding to the data blocks identified as having errors is selected, where the number of rows in the first set of rows is equal to the number of ECCs for the data set and less than the number of data blocks identified as having errors. Data for the first set of rows are generated using the ECCs for the data set, and the rows corresponding to the data blocks identified as having errors are verified based on the generated data for the first set of rows.

The present invention may be embodied in a disk drive comprising a rotating magnetic media having tracks identified by binary codewords, and in a related method. Each track codeword for a particular track within a contiguous band of tracks differs from a track codeword for an adjacent track within the contiguous band of tracks by a defined number of bits, and differs from a track codeword for a nonadjacent track within the contiguous band of tracks by at least the defined number of bits. The defined number N of bits is greater than four such that at least two bit errors may be corrected when reading a track codeword.