Sector and track level error correction system for disc storage systems

An error correction apparatus for use in a disc storage device, wherein the disc comprises a plurality of data tracks recorded thereon, a data track comprises a plurality of data sectors and at least one redundancy sector, and a sector comprises sector data bytes and sector redundancy bytes, the error correction apparatus comprising:

• (a) a data buffer connected to receive and store a data sector read from a target track;
• (b) a redundancy buffer for storing track level redundancy data associated with the redundancy sector;
• (c) a sector level error correction system for detecting and correcting errors in the sector data using the sector redundancy bytes;
• (d) a track level error correction system for reconstructing an unrecoverable data sector using the redundancy sector, thereby forming a reconstructed data sector;
• and
• (e) a means for mapping the unrecoverable data sector to a spare data sector.

An error correction apparatus for use in a disc storage device, wherein the disc comprises a plurality of data tracks recorded thereon, a data track comprises a plurality of data sectors and at least one redundancy sector, and a sector comprises sector data bytes and sector redundancy bytes, the error correction apparatus comprising:

• (a) a data buffer connected to receive and store a data sector read from a target track;
• (b) a redundancy buffer for storing track level redundancy data associated with the redundancy sector;
• (c) a sector level error correction system for detecting and correcting errors in the sector data using the sector redundancy bytes;
• (d) a track level error correction system for reconstructing an unrecoverable data sector using the redundancy sector, thereby forming a reconstructed data sector;
• and
• (e) a means for writing the reconstructed data sector to the unrecoverable data sector and rereading the unrecoverable data sector to determine if the unrecoverability persists.

In a disc storage device, wherein the disc comprises a plurality of data tracks recorded thereon, a data track comprises a plurality of data sectors and at least one redundancy sector, and a sector comprises sector data bytes and sector redundancy bytes, a method for correcting errors in at least one data sector comprising the steps of:

• (a) reading and storing a data sector in a data buffer;
• (b) correcting errors in the data sector stored in the data buffer using the sector redundancy bytes;
• (c) generating track level redundancy bytes by combining two or more uncorrected sectors read from the disc according to a predetermined error correction operation;
• (d) storing the track level redundancy bytes in a redundancy buffer;
• and
• (e) correcting errors in the track level redundancy bytes stored in the redundancy buffer using correction information generated in step (b).

In a disc storage device, wherein the disc comprises a plurality of data tracks recorded thereon, a data track comprises a plurality of data sectors and at least one redundancy sector, and a sector comprises sector data bytes and sector redundancy bytes, a method for writing a data sector to the disc comprising the steps of:

• (a) receiving a data sector from a host system to be written to the disc;
• (b) storing the received data sector in a data buffer;
• (c) reading the data sector from the data buffer and generating sector level redundancy bytes and track level redundancy bytes in response thereto, the track level redundancy bytes being stored in a redundancy buffer;
• (d) appending the sector level redundancy bytes of step (c) to the data sector of step (c) to generate a data codeword and writing the data codeword to the disc;
• (e) repeating steps (c) and (d) at least once;
• (f) reading the track level redundancy bytes from the redundancy buffer and generating sector level redundancy bytes in response thereto;
• and
• (g) appending the sector level redundancy bytes of step (f) to the track level redundancy bytes of step (f) to generate a redundancy codeword and writing the redundancy codeword to the disc.

An error correction apparatus for use in a disc storage device, wherein the disc comprises a plurality of data tracks recorded thereon, a data track comprises a plurality of data sectors and at least one redundancy sector, and a sector comprises sector data bytes and sector redundancy bytes, the error correction apparatus comprising:

• (a) a redundancy buffer for storing track level redundancy data associated with the redundancy sector;
• (b) a sector level error correction system for detecting and correcting errors in the sector data using the sector redundancy bytes;
• and
• (c) a track level error correction system for reconstructing an unrecoverable data sector using the redundancy sector and the redundancy buffer, thereby forming a reconstructed data sector, wherein the track level error correction system modifies the track level redundancy data stored in the redundancy buffer using correction data generated by the sector level error correction system.