Abstract: An apparatus may include a circuit configured to initialize a read operation to read one or more requested data segments of a respective data unit having a plurality of data segments. Based on a number of failed data segments of the requested data segments and an erasure capability of an outer code error correction scheme, the circuit may perform erasure recovery to recover the failed data segments. Based on the number of failed data segments, the erasure capability of the outer code error correction scheme, and a threshold value, the circuit may perform iterative outer code recovery to recover the failed data segments.

Abstract: Systems and methods are disclosed for implementing sector management in drives having multiple modulation coding. A circuit may be configured to generate a data sector having a first number of bits based on a first modulation encoding scheme associated with a first location of a data storage medium, determine a difference between the first number of bits and a second number of bits corresponding to a second modulation encoding scheme associated with a second location of the data storage medium, append a number of padding bits to the data sector based on the difference, and store the data sector to the second location of the data storage medium. The data sector may be a sector reallocated from the first location to the second location. The data sector may also be an intermediate parity sector stored to a media cache region of the data storage device.

Abstract: An apparatus may include a circuit that initializes a read operation to read one or more requested data segments of a respective data unit. The circuit may generate equalized combined samples for a failed data segment of the one or more requested data segments based on first samples and second samples. In addition, the circuit may perform iterative outer code recovery for the data unit utilizing the equalized combined samples as samples for the failed data segment.

Abstract: Systems and methods are disclosed for minimizing reads for reallocated sectors of a data storage medium. An apparatus may be configured to selectively skip over reallocated sectors in an LBA range without interrupting a read, via generating a skip mask or by beginning the read after the reallocated sector and reading the entire track up to the reallocated sector. When a number of sectors not read from the LBA range during the read operation is less than an amount of sectors that can be recovered based on an error correction capability, the data of the reallocated sector may be reconstructed using error correction data rather than by performing a read at the reallocated sector.

Abstract: Systems and methods are disclosed for performing segment-based outer code recovery at a data storage device. An apparatus may comprise a circuit configured to disable outer code error recovery, and perform a read operation spanning a plurality of segments of a data storage medium, a segment including a plurality of sectors. The circuit may identify one or more segments from the plurality of segments that have one or more sectors with an error. For an identified segment of the one or more segments, the circuit may perform a re-read operation with outer code error recovery enabled, and perform outer code recovery on sectors with an error within the identified segment.

Abstract: A memory medium has a plurality of tracks arranged in a plurality of sectors with each track sector having a format which does not include header fields identifying sectors or sector defects or defect management procedures. Track management apparatus identifies the track sector currently confronting a transducer; the track management being based on sector pulses (in the case of a dedicated servo system), or being calculated based on track information, an index pulse and data wedge information from previous wedges (in the case of embedded servo systems), or being derived from a lookup table. To accommodate sector defects, a defect bank contains the identity and type of each defective or spare sector.

Abstract: A memory medium has a plurality of tracks arranged in a plurality of sectors with each track sector having a format which does not include header fields identifying sectors or sector defects or defect management procedures. Track management apparatus identifies the track sector currently confronting a transducer; the track management being based on sector pulses (in the case of a dedicated servo system), or being calculated based on track information, an index pulse and data wedge information from previous wedges (in the case of embedded servo systems), or being derived from a lookup table. To accommodate sector defects, a defect bank contains the identity and type of each defective or spare sector.

Abstract: An apparatus for correcting header information includes a transducer for reading and writing encoded information to a magnetic storage medium. A serial/deserializer provides a deserialized output. Header information from the deserializer is stored in a header storage register. The deserialized header information is also provided to a header error correction circuit. The header error correction circuit provides an output indicating location and value of errors in the header memory. This information is used to correct errors in the header memory. The corrected header information is compared with predetermined header information and used to determine whether subsequent data associated with the header should be written to or read from the magnetic storage medium.