Disk drive adjusting erasure window based on a number of non-read data sectors during a retry operation
AssigneeWestern Digital Technologies, Inc.
InventorTeik Ee Yeo
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Abstract
A disk drive is disclosed comprising a disk having a plurality of data tracks, wherein each data track comprises a plurality of data sectors. A head is actuated radially over the disk in order to read one of the data sectors from a target data track on the disk. The data sector is stored in a buffer and decoded with an error correction code (ECC) decoder. When the decode fails, an erasure window is adjusted based on a number of non-read data sectors recorded in the target data track, wherein the erasure window comprises a length spanning at least one ECC symbol in the data sector. The data sector is read from the buffer and decoded with the ECC decoder using the erasure window.
Claims20
A disk drive comprising:
- a disk comprising a plurality of data tracks, wherein each data track comprises a plurality of data sectors;
- a head actuated radially over the disk;
- and
- control circuitry operable to:
- read one of the data sectors from a target data track on the disk;
- store the data sector in a buffer;
- first decode the data sector with an error correction code (ECC) decoder;
- when the first decode fails:
- adjust an erasure window based on a number of non-read data sectors recorded in the target data track, wherein the erasure window comprises a length spanning at least one ECC symbol in the data sector;
- read the data sector from the buffer;
- and
- second decode the data sector with the ECC decoder using the erasure window.
A method of operating a disk drive, the disk drive comprising a disk comprising a plurality of data tracks, wherein each data track comprises a plurality of data sectors, and a head actuated radially over the disk, the method comprising:
- reading one of the data sectors from a target data track on the disk;
- storing the data sector in a buffer;
- first decoding the data sector with an error correction code (ECC) decoder;
- when the first decoding fails:
- adjusting an erasure window based on a number of non-read data sectors recorded in the target data track, wherein the erasure window comprises a length spanning at least one ECC symbol in the data sector;
- reading the data sector from the buffer;
- and
- second decoding the data sector with the ECC decoder using the erasure window.
Dependencies are inferred from the claim text.