Granted Patent B1

US 7,872,822 · App. 11/768,288 · Granted Jan 18, 2011

Abstract

Claims (53)

1. A disk drive comprising:

a first disk surface comprising a plurality of data tracks, wherein each data track comprises a first plurality of data sectors;

a second disk surface comprising a plurality of data tracks, wherein each data track comprises a second plurality of data sectors;

a first head actuated over the first disk surface and a second head actuated over the second disk surface; and

control circuitry operable to:

access the first and second data sectors in a serpentine access pattern, wherein a plurality of refresh zones are defined relative to the serpentine access pattern;

receive a write command from a host; and

write data to at least one of the refresh zones, and update a refresh monitor associated with the refresh zone.

2. The disk drive as recited in claim 1 , wherein at least one of the refresh zones extends across one of the disk surfaces.

3. The disk drive as recited in claim 2 , wherein at least one of the refresh zones comprises a plurality of tracks on the disk surface.

4. The disk drive as recited in claim 1 , wherein at least one of the refresh zones extends across at least two disk surfaces.

5. The disk drive as recited in claim 1 , wherein:

the serpentine access pattern defines a plurality of clusters;

each cluster comprises a plurality of tracks; and

a boundary of at least one of the refresh zones aligns with a boundary of one of the clusters.

6. The disk drive as recited in claim 1 , wherein the control circuitry is further operable to:

maintain a plurality of write frequency counters for the refresh zones;

update the write frequency counter of a refresh zone when performing a write operation to the refresh zone; and

adjust the refresh zones in response to the write frequency counters.

7. The disk drive as recited in claim 6 , wherein the control circuitry is operable to adjust the number of refresh zones in response to the write frequency counters.

8. The disk drive as recited in claim 6 , wherein the control circuitry is operable to adjust a size of a refresh zone in response to the write frequency counters.

9. The disk drive as recited in claim 1 , wherein the control circuitry is further operable to:

maintain a plurality of absolute block addresses each assigned to one of the data sectors;

map a logical block address associated with an access command to a corresponding absolute block address; and

perform a refresh operation on a refresh zone by converting an absolute block address identifying the refresh zone into a logical block address of an access command and executing the access command.

10. A method of operating a disk drive, the disk drive comprising a first disk surface comprising a plurality of data tracks, wherein each data track comprises a first plurality of data sectors, a second disk surface comprising a plurality of data tracks, wherein each data track comprises a second plurality of data sectors, a first head actuated over the first disk surface and a second head actuated over the second disk surface, the method comprising:

accessing the first and second data sectors in a serpentine access pattern, wherein a plurality of refresh zones are defined relative to the serpentine access pattern;

receiving a write command from a host; and

writing data to at least one of the refresh zones, and updating a refresh monitor associated with the refresh zone.

11. The method as recited in claim 10 , wherein at least one of the refresh zones extends across one of the disk surfaces.

12. The method as recited in claim 11 , wherein at least one of the refresh zones comprises a plurality of tracks on the disk surface.

13. The method as recited in claim 10 , wherein at least one of the refresh zones extends across at least two disk surfaces.

14. The method as recited in claim 10 , wherein:

the serpentine access pattern defines a plurality of clusters;

each cluster comprises a plurality of tracks; and

a boundary of at least one of the refresh zones aligns with a boundary of one of the clusters.

15. The method as recited in claim 10 , further comprising:

maintaining a plurality of write frequency counters for the refresh zones;

updating the write frequency counter of a refresh zone when performing a write operation to the refresh zone; and

adjusting the refresh zones in response to the write frequency counters.

16. The method as recited in claim 15 , further comprising adjusting the number of refresh zones in response to the write frequency counters.

17. The method as recited in claim 15 , further comprising adjusting a size of a refresh zone in response to the write frequency counters.

18. The method as recited in claim 10 , further comprising:

maintaining a plurality of absolute block addresses each assigned to one of the data sectors;

mapping a logical block address associated with an access command to a corresponding absolute block address; and

performing a refresh operation on a refresh zone by converting an absolute block address identifying the refresh zone into a logical block address of an access command and executing the access command.

19. A disk drive comprising:

a first disk surface comprising a plurality of data tracks, wherein each data track comprises a first plurality of data sectors;

a second disk surface comprising a plurality of data tracks, wherein each data track comprises a second plurality of data sectors;

a first head actuated over the first disk surface and a second head actuated over the second disk surface;

a means for accessing the first and second data sectors in a serpentine access pattern, wherein a plurality of refresh zones are defined relative to the serpentine access pattern;

a means for receiving a write command from a host; and

a means for writing data to at least one of the refresh zones, and for updating a refresh monitor associated with the refresh zone.

Assignments (8)