Method and apparatus for data error recovery using defect threshold detector and viterbi gain
AssigneeSeagate Technology LLC
InventorsKhong Mau Ling, Myint Ngwe, Kah Liang Gan, Lakshmi Anantha Challa, Quek Leong Choo
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Abstract
A method and apparatus are provided for reading from a storage medium to form data values. A signal is generated from a sector on the storage medium and a section of that signal is identified as having a change in amplitude. A gain multiplier is activated to multiply that section of the signal by a gain value. The gain multiplier is deactivated at the end of the section so that the remaining portion of the sector signal is not multiplied by the gain value. This results in a defect adjusted signal that is applied to a detector to detect data values.
Claims16
A method of reading from a storage medium to form data values, the method comprising steps of:
- (a) generating a signal from a sector of the storage medium;
- (b) identifying a section of the signal that has a change in amplitude;
- (c) activating a gain multiplier to multiply the section of the signal by a gain value during the section of the signal that has a change in amplitude and deactivating the gain multiplier at the end of the section, to produce a defect adjusted signal;
- and
- (d) detecting data values in the defect adjusted signal.
In a disc drive, reading and recovery components for converting patterns on a medium into read data, the reading and recovery components comprising:
- a read head that generates a read signal from a sector of patterns on the medium;
- a defect threshold detector that receives a first form of the read signal and identifies at least one section of the read signal as a defect section having abnormal amplitudes;
- a gain multiplier that receives a second form of the read signal and that forms a defect adjusted read signal by multiplying sections of the second form of the read signal that corresponds to the defect sections by a gain value without multiplying the remainder of the second form of the read signal by the gain value;
- and
- a detector that converts the defect adjusted read signal into data values.
A disc drive for reading data from tracks along a disc, the disc drive comprising:
- an actuator assembly with a read head that is able to position the read head relative to a track;
- and
- reading means coupled to the head of the actuator assembly for converting a read signal generated by the head into data values.
Dependencies are inferred from the claim text.