Dynamic track misregistration dependent error scans

Patent metadata

Field	Value
Publication number	US-9330701-B1
Application number	US-201414571270-A
Country	US
Kind code	B1
Filing date	Dec 15, 2014
Priority date	Dec 15, 2014
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

Systems and methods are disclosed for using track misregistration values, representing an amount of off-track deviation of a write element, to dynamically increment error scan counters for proximate storage areas. In certain embodiments, an apparatus may comprise a processor configured to perform a write operation to record data to a target track of a data storage medium using a write element, determine an amount of deviation of the write element from a center line of the target track, and increment an error scan counter for an area of the data storage medium proximate to the target track based on the amount of deviation.

First claim

What is claimed is:

1. An apparatus comprising:
a processor configured to:
perform a write operation to record data to a target track of a data storage medium using a write element;
determine an amount of deviation of the write element from a center line of the target track; and
increment an error scan counter for an area of the data storage medium proximate to the target track based on the amount of deviation.

2. The apparatus of claim 1 comprising the processor further configured to:
determine a nominal increment value associated with the write element; and
increment the error scan counter based on the nominal increment value modified based on the amount of deviation.

3. The apparatus of claim 2 comprising the processor further configured to:
modify the nominal increment value by a first amount if the amount of deviation indicates the write element deviated from the center line in a direction away from the area of the data storage medium proximate to the target track; and
modify the nominal increment value by a second amount greater than the first amount if the amount of deviation indicates the write element deviated from the center line in a direction towards the area of the data storage medium proximate to the target track.

4. The apparatus of claim 2 comprising the processor further configured to:
retrieve the nominal increment value from a table, the nominal increment value set based on testing performed on the write element.

5. The apparatus of claim 1 comprising the processor further configured to:
determine a first value for an increment modifier if the amount of deviation does not exceed a first deviation threshold;
determine a second value for the increment modifier if the amount of deviation exceeds the first deviation threshold;
determine a third value for the increment modifier if the amount of deviation exceeds a second deviation threshold; and
increment the error scan counter based on the increment modifier.

6. The apparatus of claim 1 comprising the processor further configured to:
determine whether the error scan counter for the area exceeds an error scan threshold; and
perform an error scan on the area when the error scan counter exceeds the error scan threshold.

7. The apparatus of claim 6 comprising the processor further configured to:
determine whether a number of errors detected in the error scan exceeds an error threshold; and
refresh data of the area when the number of errors exceeds the error threshold.

8. The apparatus of claim 1 further comprising the area includes a data track near the target track and influenced by the write operation to the target track.

9. The apparatus of claim 8 comprising the processor further configured to:
determine the amount of deviation for multiple sections of the target track; and
increment the error scan counter for the data track near the target track based on a section from the multiple sections with a highest deviation.

10. The apparatus of claim 1 comprising the processor further configured to:
determine the amount of deviation based on a position error signal obtained from the target track.

11. A method comprising:
maintain error scan counters for areas of a data storage medium to determine when to perform an error scan on the areas;
performing a write operation to record data to a target track of a data storage medium using a write element;
determining an amount of deviation of the write element from a center line of the target track; and
incrementing an error scan counter for an area of the data storage medium proximate to the target track based on the amount of deviation.

12. The method of claim 11 further comprising:
determining a nominal increment value associated with the write element; and
incrementing the error scan counter based on the nominal increment value modified based on the amount of deviation.

13. The method of claim 12 further comprising:
modifying the nominal increment value by a first amount if the amount of deviation indicates the write element deviated from the center line in a direction away from the area of the data storage medium proximate to the target track; and
modifying the nominal increment value by a second amount greater than the first amount if the amount of deviation indicates the write element deviated from the center line in a direction towards the area of the data storage medium proximate to the target track.

14. The method of claim 11 further comprising:
determining a first value for an increment modifier if the amount of deviation does not exceed a first deviation threshold;
determining a second value for the increment modifier if the amount of deviation exceeds the first deviation threshold;
determining a third value for the increment modifier if the amount of deviation exceeds a second deviation threshold; and
incrementing the error scan counter based on the increment modifier.

15. The method of claim 11 further comprising:
performing an error scan on the area when the error scan counter exceeds an error scan threshold; and
refreshing data of the area when a number of errors detected in the error scan exceeds a specified error threshold.

16. A memory device storing instructions that, when executed, cause a processor to perform a method comprising:
performing a write operation to record data to a target track of a data storage medium using a write element;
determining an amount of deviation of the write element from a center line of the target track; and
incrementing an error scan counter for an area of the data storage medium proximate to the target track based on the amount of deviation.

17. The memory device of claim 16 , the method further comprising:
incrementing the error scan counter based on a nominal increment value associated with the write element modified based on the amount of deviation;
modifying a nominal increment value by a first amount if the amount of deviation indicates the write element deviated from the center line in a direction away from the area of the data storage medium proximate to the target track; and
modifying the nominal increment value by a second amount greater than the first amount if the amount of deviation indicates the write element deviated from the center line in a direction towards the area of the data storage medium proximate to the target track.

18. The memory device of claim 16 , the method further comprising:
determining a first value for an increment modifier if the amount of deviation does not exceed a first deviation threshold;
determining a second value for the increment modifier if the amount of deviation exceeds the first deviation threshold;
determining a third value for the increment modifier if the amount of deviation exceeds a second deviation threshold; and
incrementing the error scan counter based on the increment modifier.

19. The memory device of claim 16 , the method further comprising:
the area includes a data track near the target track and influenced by the write operation to the target track;
determining the amount of deviation per section less than all of the target track; and
incrementing the error scan counter for the data track near the target track based on a section of the target track with the highest deviation.

20. The memory device of claim 16 , the method further comprising:
determining a proximity of the write element to the area of the data storage medium based on the amount of deviation; and
incrementing the error scan counter by an increas

Assignees

• Seagate Technology Llc

Inventors

• Michel Richard P
• Christensen Joshua W

Classifications

• G11B20/18

  Error detection or correction; Testing {, e.g. of drop-outs} · CPC title

• G11B5/59627 Primary

  Aligning for runout, eccentricity or offset compensation (G11B5/5534, G11B5/59677, G11B5/59688 take precedence) · CPC title

• G11B20/1816 Primary

  Testing · CPC title

• G11B5/012

  Recording on, or reproducing or erasing from, magnetic disks (G11B17/00, G11B19/00 take precedence) · CPC title