Track measurement for data storage device
First Claim
1. A Data Storage Device (DSD), comprising:
- a disk for storing data;
a head for reading and writing data on the disk; and
a controller configured to;
control the head to write test data in a plurality of sectors in a test track on the disk;
control the head to write an adjacent track on the disk that is offset from the test track by an offset distance;
control the head to read data from the plurality of sectors in the test track from an Off-Track Read Capability (OTRC) position on the disk outside of the test track;
determine an OTRC value for each sector of the plurality of sectors in the test track by varying the OTRC position and determining whether the sector meets a criterion for correctly reading data from the sector;
calculate an average OTRC value for the plurality of sectors in the test track;
calculate a standard deviation of the OTRC values for the plurality of sectors in the test track;
determine whether the average OTRC value for the plurality of sectors is greater than or equal to a predetermined multiple of the standard deviation of the OTRC values for the plurality of sectors; and
if it is determined that the average OTRC value is greater than or equal to the predetermined multiple of the standard deviation of the OTRC values, control the head to rewrite the adjacent track at a decreased offset distance.
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0 Petitions
Accused Products
Abstract
Track placement on a disk of a Data Storage Device (DSD) including writing test data in a plurality of sectors in a test track on the disk. An adjacent track on the disk is written offset from the test track by an offset distance. Data is read from the test track from an Off-Track Read Capability (OTRC) position outside of the test track. An OTRC value is determined for each sector of the plurality of sectors by varying the OTRC position and determining whether the sector meets a criterion for correctly reading data from the sector. An average OTRC value and a standard deviation are calculated for the plurality of sectors. If it is determined that the average OTRC value is greater than or equal to the predetermined multiple of the standard deviation of the OTRC values, the adjacent track is rewritten at a decreased offset distance.
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Citations
23 Claims
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1. A Data Storage Device (DSD), comprising:
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a disk for storing data; a head for reading and writing data on the disk; and a controller configured to; control the head to write test data in a plurality of sectors in a test track on the disk; control the head to write an adjacent track on the disk that is offset from the test track by an offset distance; control the head to read data from the plurality of sectors in the test track from an Off-Track Read Capability (OTRC) position on the disk outside of the test track; determine an OTRC value for each sector of the plurality of sectors in the test track by varying the OTRC position and determining whether the sector meets a criterion for correctly reading data from the sector; calculate an average OTRC value for the plurality of sectors in the test track; calculate a standard deviation of the OTRC values for the plurality of sectors in the test track; determine whether the average OTRC value for the plurality of sectors is greater than or equal to a predetermined multiple of the standard deviation of the OTRC values for the plurality of sectors; and if it is determined that the average OTRC value is greater than or equal to the predetermined multiple of the standard deviation of the OTRC values, control the head to rewrite the adjacent track at a decreased offset distance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 16, 17, 18, 19, 20, 21, 22)
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11. A method for measuring track placement on a disk of a Data Storage Device (DSD), the method comprising:
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writing test data in a plurality of sectors in a test track on the disk; writing an adjacent track on the disk that is offset from the test track by an offset distance; reading data from the plurality of sectors in the test track from an Off-Track Read Capability (OTRC) position on the disk outside of the test track; determining an OTRC value for each sector of the plurality of sectors in the test track by varying the OTRC position and determining whether the sector meets a criterion for correctly reading data from the sector; calculating an average OTRC value for the plurality of sectors in the test track; calculating a standard deviation of the OTRC values for the plurality of sectors in the test track; determining whether the average OTRC value for the plurality of sectors is greater than or equal to a predetermined multiple of the standard deviation of the OTRC values for the plurality of sectors; and if it is determined that the average OTRC value is greater than or equal to the predetermined multiple of the standard deviation of the OTRC values, rewriting the adjacent track at a decreased offset distance. - View Dependent Claims (12, 13, 14, 15)
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23. A computer-readable medium storing computer-executable instructions for measuring track placement on a disk of a Data Storage Device (DSD), wherein when the computer-executable instructions are executed by a controller or a processor, the computer-executable instructions cause the controller or processor to:
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control a head of the DSD to write test data in a plurality of sectors in a test track on the disk; control the head to write an adjacent track on the disk that is offset from the test track by an offset distance; control the head to read data from the plurality of sectors in the test track from an Off-Track Read Capability (OTRC) position on the disk outside of the test track; determine an OTRC value for each sector of the plurality of sectors in the test track by varying the OTRC position and determining whether the sector meets a criterion for correctly reading data from the sector; calculate an average OTRC value for the plurality of sectors in the test track; calculate a standard deviation of the OTRC values for the plurality of sectors in the test track; determine whether the average OTRC value for the plurality of sectors is greater than or equal to a predetermined multiple of the standard deviation of the OTRC values for the plurality of sectors; and if it is determined that the average OTRC value is greater than or equal to the predetermined multiple of the standard deviation of the OTRC values, control the head to rewrite the adjacent track at a decreased offset distance.
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Specification