Method and system for compensating for adjacent tracks during writing of data

• US 8,625,215 B1
• Filed: 03/06/2012
• Issued: 01/07/2014
• Est. Priority Date: 03/21/2011
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Burd, Gregory, Nangare, Nitin
• Primary Examiner(s): Edun, Muhammad N
• Application Number:
  US13/413,049
• Time in Patent Office: 672 Days
• Field of Search: None
• US Class Current: 360/31
• CPC Class Codes: G11B 19/045 by detecting mistracking
• CPC Class Codes: G11B 20/1879 Direct read-after-write methods
• CPC Class Codes: G11B 2220/2516 Hard disks
• CPC Class Codes: G11B 27/36 Monitoring, i.e. supervising the progress of recording or reproducing for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence

Abstract

A method of writing data to a storage device includes writing current data to a first track of data, monitoring write head position, and on detection of encroachment of the write head position on a second track of previously written data, using the current data to recover the previously written data on the second track, and rewriting the current data to the first track. A storage controller includes a device controller that writes data to a current track of data on a storage device. The device controller monitors write head position. On detection of encroachment of the write head position on a second track of previously written data uses the current data to recover the previously written data on the second track, and rewrites the current data to the first track. A storage system includes a storage medium having a plurality of tracks of data thereon, and a storage controller.

Claims

1. A method of writing data to a storage device, the method comprising:

writing current data to a first track of data;

monitoring write head position during the writing of the current data to the first track of data; and

on detection of encroachment of the write head position on a second track of previously written data;

stopping the writing of the current data to the first track of data;

after the stopping, using the current data to recover the previously written data on the second track; and

rewriting the current data to the first track after recovery of the previously written data on the second track.

2. The method of claim 1 wherein:

the writing of the current data comprises storing the current data in a buffer; and

the using of the current data comprises reading the current data from the buffer.

3. The method of claim 2 wherein the rewriting comprises again reading the current data from the buffer.

4. The method of claim 1 wherein the using of the current data comprises re-reading the current data from first track.

5. The method of claim 4 wherein:

the re-reading the current data from the first track comprises storing the current data in a buffer; and

the rewriting comprises reading the current data from the buffer.

6. The method of claim 1 wherein:

the writing of the current data comprises storing the current data in a buffer; and

the rewriting comprises reading the current data from the buffer.

7. The method of claim 1 wherein the monitoring write head position comprises comparing a position error signal to a threshold value.

8. A storage controller comprising:

a device controller; and

a write channel including a write head;

wherein;

the storage medium has a plurality of tracks of data thereon; and

when said device controller writes data to a current track of data on said storage device, said device controller;

monitors write head position, and

on detection of encroachment of the write head position on a second track of previously written data;

stops the writing of the current data to the first track of data,

after stopping the writing of the current data to the first track of data, uses the current data to recover the previously written data on the second track, and

rewrites the current data to the first track after recovery of the previously written data on the second track.

9. The storage controller of claim 8 further comprising a buffer;

wherein;

the writing of the current data comprises storing the current data in the buffer; and

the device controller uses the current data by reading the current data from the buffer.

10. The storage controller of claim 9 wherein the device controller rewrites the current data after again reading the current data from the buffer.

11. The storage controller of claim 8 wherein the device controller uses the current data by re-reading the current data from first track.

12. The storage controller of claim 11 wherein the device controller:

stores the current data in a buffer; and

re-reads the current data from the first track by reading the current data from the buffer; and

rewrites the current data to the first track after re-reading the current data from the buffer.

13. The storage controller of claim 8 wherein the device controller:

stores the current data in a buffer; and

rewrites the current data to the first track after re-reading the current data from the buffer.

14. A storage system comprising:

a storage medium having a plurality of tracks of data thereon; and

a storage controller comprising;

a device controller, and

a write channel including a write head;

wherein;

the storage medium has a plurality of tracks of data thereon; and

when said device controller writes data to a current track of data on said storage device, said device controller;

monitors write head position, and

on detection of encroachment of the write head position on a second track of previously written data;

stops the writing of the current data to the first track of data,

after stopping the writing of the current data to the first track of data, uses the current data to recover the previously written data on the second track, and

rewrites the current data to the first track after recovery of the previously written data on the second track.

15. The storage system of claim 14 further comprising a buffer;

wherein;

the writing of the current data comprises storing the current data in the buffer; and

the device controller uses the current data by reading the current data from the buffer.

16. The storage system of claim 15 wherein the device controller rewrites the current data after again reading the current data from the buffer.

17. The storage system of claim 14 wherein the device controller uses the current data by re-reading the current data from first track.

18. The storage system of claim 17 wherein the device controller:

stores the current data in a buffer; and

re-reads the current data from the first track by reading the current data from the buffer; and

rewrites the current data to the first track after re-reading the current data from the buffer.

19. The storage system of claim 14 wherein the device controller:

stores the current data in a buffer; and

rewrites the current data to the first track after re-reading the current data from the buffer.