Granted Patent B1

US 9,437,242 · App. 14/853,313 · Granted Sep 6, 2016

Abstract

Claims (123)

1. A data storage device comprising:

a disk comprising a plurality of data tracks each comprising a plurality of data sectors;

a head actuated over the disk; and

control circuitry configured to write a first frequency preamble to a first data sector of a first data track and write a second frequency preamble to a second data sector of a second data track, wherein:

the first frequency is different from the second frequency; and

the first data track is adjacent to the second data track,

wherein the control circuitry is further configured to:

first read the first data sector to generate a first read signal;

process the first read signal to recover data from the first data sector; and

when the first read fails, execute a retry operation by at least:

evaluating a frequency component of the first read signal corresponding to the first frequency preamble of the first data sector;

generating a jog value based on the frequency component of the first read signal; and

second reading the first data sector by offsetting the head away from the first data track based on the jog value.

2. The data storage device as recited in claim 1 , wherein the control circuitry is further configured to write a third frequency preamble to a third data sector of a third data track, wherein:

the third frequency is different from the first and second frequency; and

the third data track is adjacent to the first data track.

3. The data storage device as recited in claim 1 , wherein the control circuitry is further configured to generate the jog value based on a magnitude of the first frequency in the frequency component and a magnitude of the second frequency in the frequency component.

4. The data storage device as recited in claim 1 , wherein the control circuitry is further configured to execute the retry operation by further:

adjusting the jog value based on a frequency component of a second read signal generated when reading the first frequency preamble during the second reading of the first data sector; and

third reading the first data sector based on the adjusted jog value.

5. The data storage device as recited in claim 4 , wherein the control circuitry is further configured to adjust the jog value in a direction that increases a magnitude of the first frequency in the frequency component when reading the first frequency preamble of the first data sector.

6. The data storage device as recited in claim 1 , wherein the control circuitry is further configured to execute a read operation of the first data track by at least:

reading the first data sector to generate a first read signal;

evaluating a frequency component of the first read signal corresponding to the first frequency preamble of the first data sector;

generating a preamble position error signal (PES) based on the frequency component; and

servoing the head over the first data track based on the preamble PES.

7. The data storage device as recited in claim 6 , wherein the control circuitry is further configured to read a third data sector in the first data track while servoing the head over the first data track based on the preamble PES.

8. The data storage device as recited in claim 6 , wherein the data tracks are defined by a plurality of servo sectors each comprising servo bursts, and the control circuitry is further configured to execute the read operation of the first data track by at least:

seeking the head to the first data track based on the servo sectors;

settling the head onto the first data track based on a servo burst PES generated by reading the servo bursts in the servo sectors; and

disabling the servo burst PES while reading at least part of the first data track.

9. The data storage device as recited in claim 1 , wherein the data tracks are defined by a plurality of servo sectors each comprising servo bursts, and the control circuitry is further configured to execute a read operation of the first data track by at least:

reading the servo bursts of the servo sectors that define the first data track to generate a servo burst position error signal (PES);

reading the first data sector to generate a first read signal;

evaluating a frequency component of the first read signal corresponding to the first frequency preamble of the first data sector;

generating a preamble PES based on the frequency component; and

rewriting at least part of the first data track based on a difference between the servo burst PES and the preamble PES.

10. A method of operating a data storage device, the method comprising:

writing a first frequency preamble to a first data sector of a first data track on a disk and writing a second frequency preamble to a second data sector of a second data track on the disk, wherein:

the first frequency is different from the second frequency; and

the first data track is adjacent to the second data track,

first reading the first data sector to generate a first read signal;

processing the first read signal to recover data from the first data sector; and

when the first read fails, executing a retry operation by at least:

evaluating a frequency component of the first read signal corresponding to the first frequency preamble of the first data sector;

generating a jog value based on the frequency component of the first read signal; and

second reading the first data sector by offsetting a head away from the first data track based on the jog value.

11. The method as recited in claim 10 , further comprising writing a third frequency preamble to a third data sector of a third data track on the disk, wherein:

the third frequency is different from the first and second frequency; and

the third data track is adjacent to the first data track.

12. The method as recited in claim 10 , further comprising generating the jog value based on a magnitude of the first frequency in the frequency component and a magnitude of the second frequency in the frequency component.

13. The method as recited in claim 10 , wherein

executing the retry operation further comprises:

adjusting the jog value based on a frequency component of a second read signal generated when reading the first frequency preamble during the second reading of the first data sector; and

third reading the first data sector based on the adjusted jog value.

14. The method as recited in claim 13 , further comprising adjusting the jog value in a direction that increases a magnitude of the first frequency in the frequency component when reading the first frequency preamble of the first data sector.

15. The method as recited in claim 10 , further comprising executing a read operation of the first data track by at least:

reading the first data sector to generate a first read signal;

evaluating a frequency component of the first read signal corresponding to the first frequency preamble of the first data sector;

generating a preamble position error signal (PES) based on the frequency component; and

servoing a head over the first data track based on the preamble PES.

16. The method as recited in claim 15 , further comprising reading a third data sector in the first data track while servoing the head over the first data track based on the preamble PES.

17. The method as recited in claim 15 , wherein the data tracks are defined by a plurality of servo sectors each comprising servo bursts, and the method further comprises executing the read operation of the first data track by at least:

seeking the head to the first data track based on the servo sectors;

settling the head onto the first data track based on a servo burst PES generated by reading the servo bursts in the servo sectors; and

disabling the servo burst PES while reading at least part of the first data track.

18. The method as recited in claim 10 , wherein the data tracks are defined by a plurality of servo sectors each comprising servo bursts, and the method further comprises executing a read operation of the first data track by at least:

reading the servo bursts of the servo sectors that define the first data track to generate a servo burst position error signal (PES);

reading the first data sector to generate a first read signal;

evaluating a frequency component of the first read signal corresponding to the first frequency preamble of the first data sector;

generating a preamble PES based on the frequency component; and

rewriting at least part of the first data track based on a difference between the servo burst PES and the preamble PES by a threshold.

19. A data storage device comprising:

a disk comprising a plurality of data tracks each comprising a plurality of data sectors, wherein the data tracks are defined by a plurality of servo sectors each comprising servo bursts;

a head actuated over the disk; and

control circuitry configured to:

write a first frequency preamble to a first data sector of a first data track and write a second frequency preamble to a second data sector of a second data track, wherein:

the first frequency is different from the second frequency; and

the first data track is adjacent to the second data track;

execute a read operation of the first data track by at least:

seeking the head to the first data track based on the servo sectors;

settling the head onto the first data track based on a servo burst PES generated by reading the servo bursts in the servo sectors;

reading the first data sector to generate a first read signal;

evaluating a frequency component of the first read signal corresponding to the first frequency preamble of the first data sector;

generating a preamble position error signal (PES) based on the frequency component;

servoing the head over the first data track based on the preamble PES; and

disabling the servo burst PES while reading at least part of the first data track.

20. A data storage device comprising:

a disk comprising a plurality of data tracks each comprising a plurality of data sectors, wherein the data tracks are defined by a plurality of servo sectors each comprising servo bursts;

a head actuated over the disk; and

control circuitry configured to write a first frequency preamble to a first data sector of a first data track and write a second frequency preamble to a second data sector of a second data track, wherein:

the first frequency is different from the second frequency; and

the first data track is adjacent to the second data track;

execute a read operation of the first data track by at least:

reading the servo bursts of the servo sectors that define the first data track to generate a servo burst position error signal (PES);

reading the first data sector to generate a first read signal;

evaluating a frequency component of the first read signal corresponding to the first frequency preamble of the first data sector;

generating a preamble PES based on the frequency component; and

rewriting at least part of the first data track based on a difference between the servo burst PES and the preamble PES.

21. The data storage device as recited in claim 20 , wherein the control circuitry is further configured to rewrite at least part of the second data track based on the difference between the servo burst PES and the preamble PES by a threshold.

22. A method of operating a data storage device, the method comprising:

writing a first frequency preamble to a first data sector of a first data track on a disk and writing a second frequency preamble to a second data sector of a second data track on the disk, wherein:

the first frequency is different from the second frequency; and

the first data track is adjacent to the second data track;

executing a read operation of the first data track by at least:

seeking a head to the first data track based on servo sectors that define the first data track;

settling the head onto the first data track based on a servo burst PES generated by reading servo bursts in the servo sectors;

reading the first data sector to generate a first read signal;

evaluating a frequency component of the first read signal corresponding to the first frequency preamble of the first data sector;

generating a preamble position error signal (PES) based on the frequency component;

servoing the head over the first data track based on the preamble PES; and

disabling the servo burst PES while reading at least part of the first data track.

23. A method of operating a data storage device, the method comprising:

writing a first frequency preamble to a first data sector of a first data track on a disk and writing a second frequency preamble to a second data sector of a second data track on the disk, wherein:

the first frequency is different from the second frequency; and

the first data track is adjacent to the second data track;

executing a read operation of the first data track by at least:

reading the servo bursts of the servo sectors that define the first data track to generate a servo burst position error signal (PES);

reading the first data sector to generate a first read signal;

evaluating a frequency component of the first read signal corresponding to the first frequency preamble of the first data sector;

generating a preamble PES based on the frequency component; and

rewriting at least part of the first data track based on a difference between the servo burst PES and the preamble PES.

24. The method as recited in claim 23 , further comprising rewriting at least part of the second data track based on the difference between the servo burst PES and the preamble PES.

Assignments (7)