8231results about "Digital signal error detection/correction" patented technology

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 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.

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 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.

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 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 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.