Granted Patent B2

US 9,224,421 · App. 14/200,228 · Granted Dec 29, 2015

Inventors: Bruce A. Wilson (San Jose, CA); Nayak Ratnakar Aravind (Allentown, PA); Haitao Xia (San Jose, CA)

Assignee: Avago Technologies General IP (Singapore) Pte. Ltd.

G11B20/10324G11B5/012G11B20/10027G11B20/10037

Abstract

Claims (70)

1. A computing-device implemented method comprising:

receiving a magnetic read head transducer output;

computing a mean value of the magnetic read head transducer output;

computing a median value of the magnetic read head transducer output, wherein the computing a median value of the magnetic read head transducer output includes:

receiving a current estimate of the median value of the magnetic read head transducer output;

comparing the current estimate of the median value of the magnetic read head transducer output to the magnetic read head transducer output; and

generating an updated estimate of the median value of the magnetic read head transducer output according to the comparison; and

applying a correction coefficient to a magnetic read head detector input according to at least the mean value of the magnetic read head transducer output and the median value of the magnetic read head transducer output.

2. The computing-device implemented method of claim 1 , wherein the computing a median value of the magnetic read head transducer output includes:

sorting a plurality of samples of the magnetic read head transducer output; and

selecting a median value from sorted samples of the magnetic read head transducer output.

3. The computing-device implemented method of claim 1 , wherein the comparing the current estimate of the median value of the magnetic read head transducer output to the magnetic read head transducer output includes:

setting an update value as a first value when the median value of the magnetic read head transducer output is greater than the magnetic read head transducer output; and

setting the update value as a second value different than the first value when the median value of the magnetic read head transducer output is greater than the magnetic read head transducer output.

4. The computing-device implemented method of claim 3 , wherein the generating an updated estimate of the median value of the magnetic read head transducer output according to the comparison includes:

computing an updated median value of the magnetic read head transducer output according to the update value.

5. The computing-device implemented method of claim 4 , wherein the computing an updated median value of the magnetic read head transducer output according to the update value includes:

computing an updated median value of the magnetic read head transducer as a sum of:

the median value of the magnetic read head transducer; and

a product of the update value and a mean value update coefficient.

6. The computing-device implemented method of claim 5 , wherein the applying a correction coefficient to a magnetic read head detector input according to at least the mean value of the magnetic read head transducer output and the median value of the magnetic read head transducer output includes:

computing a difference between the mean value of the magnetic read head transducer and the updated median value of the magnetic read head transducer; and

computing the correction coefficient by scaling the difference.

7. The computing-device implemented method of claim 1 , wherein the applying a correction coefficient to a magnetic read head detector input according to at least the mean value of the magnetic read head transducer output and the median value of the magnetic read head transducer output includes:

computing a difference between the mean value of the magnetic read head transducer and the median value of the magnetic read head transducer; and

computing the correction coefficient by scaling the difference.

8. A system comprising:

at least one computing device; and

one or more instructions which, when implemented in the at least one computing device, configure the at least one computing device for at least:

receiving a magnetic read head transducer output;

computing a mean value of the magnetic read head transducer output;

computing a median value of the magnetic read head transducer output, wherein the computing a median value of the magnetic read head transducer output includes:

receiving a current estimate of the median value of the magnetic read head transducer output;

comparing the current estimate of the median value of the magnetic read head transducer output to the magnetic read head transducer output; and

generating an updated estimate of the median value of the magnetic read head transducer output according to the comparison; and

applying a correction coefficient to a magnetic read head detector input according to at least the mean value of the magnetic read head transducer output and the median value of the magnetic read head transducer output.

9. The system of claim 8 , wherein the comparing the current estimate of the median value of the magnetic read head transducer output to the magnetic read head transducer output includes:

setting an update value as a first value when the median value of the magnetic read head transducer output is greater than the magnetic read head transducer output; and

setting the update value as a second value different than the first value when the median value of the magnetic read head transducer output is greater than the magnetic read head transducer output.

10. The system of claim 9 , wherein the generating an updated estimate of the median value of the magnetic read head transducer output according to the comparison includes:

computing an updated median value of the magnetic read head transducer output according to the update value.

11. The system of claim 10 , wherein the computing an updated median value of the magnetic read head transducer output according to the update value includes:

computing an updated median value of the magnetic read head transducer as a sum of:

the median value of the magnetic read head transducer; and

a product of the update value and a mean value update coefficient.

12. The system of claim 11 , wherein the applying a correction coefficient to a magnetic read head detector input according to at least the mean value of the magnetic read head transducer output and the median value of the magnetic read head transducer output includes:

computing a difference between the mean value of the magnetic read head transducer and the updated median value of the magnetic read head transducer; and

computing the correction coefficient by scaling the difference.

13. The system of claim 8 , wherein the system further comprises:

a plurality of data storage devices configured as a redundant array of independent disks (RAID), wherein at least one data storage device of the plurality of data storage devices includes the magnetic read head transducer.

14. A system comprising:

circuitry for receiving a magnetic read head transducer output;

circuitry for computing a mean value of the magnetic read head transducer output;

circuitry for computing a median value of the magnetic read head transducer output, wherein the computing a median value of the magnetic read head transducer output includes:

circuitry for receiving a current estimate of the median value of the magnetic read head transducer output;

circuitry for comparing the current estimate of the median value of the magnetic read head transducer output to the magnetic read head transducer output; and

circuitry for generating an updated estimate of the median value of the magnetic read head transducer output according to the comparison; and

circuitry for applying a correction coefficient to a magnetic read head detector input according to at least the mean value of the magnetic read head transducer output and the median value of the magnetic read head transducer output.

15. The system of claim 14 , wherein the circuitry for comparing the current estimate of the median value of the magnetic read head transducer output to the magnetic read head transducer output includes:

circuitry for setting an update value as a first value when the median value of the magnetic read head transducer output is greater than the magnetic read head transducer output; and

circuitry for setting the update value as a second value different than the first value when the median value of the magnetic read head transducer output is greater than the magnetic read head transducer output.

16. The system of claim 15 , wherein the circuitry for generating an updated estimate of the median value of the magnetic read head transducer output according to the comparison includes:

circuitry for computing an updated median value of the magnetic read head transducer output according to the update value.

17. The system of claim 16 , wherein the circuitry for computing an updated median value of the magnetic read head transducer output according to the update value includes:

circuitry for computing an updated median value of the magnetic read head transducer as a sum of:

the median value of the magnetic read head transducer; and

a product of the update value and a mean value update coefficient.

18. The system of claim 17 , wherein the circuitry for applying a correction coefficient to a magnetic read head detector input according to at least the mean value of the magnetic read head transducer output and the median value of the magnetic read head transducer output includes:

circuitry for computing a difference between the mean value of the magnetic read head transducer and the updated median value of the magnetic read head transducer; and

circuitry for computing the correction coefficient by scaling the difference.

Assignments (10)

Continuity (1)