Data sector error tracking and correction mechanism

• US 20030061552A1
• Filed: 02/07/2002
• Published: 03/27/2003
• Est. Priority Date: 09/27/2001
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Su, Hui, Moller, Gregory P.
• Granted Patent: US 6,993,688 B2
• Time in Patent Office: Days
• US Class Current: 714/708
• CPC Class Codes: G11B 20/1816 Testing
• CPC Class Codes: G11B 20/1879 Direct read-after-write methods
• CPC Class Codes: G11B 2005/001 Controlling recording characteristics of record carriers or transducing characteristics of transducers by means not being part of their structure
• CPC Class Codes: G11B 2020/183 wherein at least one additional attempt is made to read or write the data when a first attempt is unsuccessful
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence

Abstract

A method is provided for reducing growth errors in disc drive. First, a number of sectors to be read is determined. Data is then read from all sectors of the number of sectors on a disc during a first disc revolution. Next, error sectors having a number of errors above a predetermined threshold are identified. The error sectors are then corrected and written to the disc during a second disc revolution. In addition, a disc drive having a controller for implementing the above method is provided.

Claims

1. A method of reducing growth errors in a disc drive storage system, the method comprising:

determining a number of sectors to be read from a disc;

reading data from all sectors of the number of sectors during a first disc revolution;

identifying error sectors having a number of errors above a predetermined threshold;

correcting the data from the error sectors; and

writing corrected data to the error sectors during a second disc revolution.

2. The method of claim 1 wherein the step of identifying includes tracking a number of errors in each sector.

3. The method of claim 1 and further comprising providing a signal for each sector indicative of whether each sector is an error sector or a non-error sector and generating a mask based on the signals.

4. The method of claim 3 wherein writing data from the error sectors comprises writing only the error sectors based on the signals for each sector indicative of whether each sector is an error sector or not.

5. The method of claim 3, and further comprising storing the mask in a buffer.

6. The method of claim 1 and further comprising reading data from only the error sectors during an intermediate disc revolution.

7. The method of claim 6 wherein the intermediate disc revolution occurs between the first and second disc revolutions.

8. The method of claim 1 wherein the step of reading data from the error sectors includes storing data in a buffer.

9. The method of claim 1 wherein the step of correcting includes using error correction code.

10. A disc drive storage system, comprising:

a rotating disc having a disc surface;

a transducer configured to read and write data from the disc surface;

a buffer memory; and

a controller configured to determine a number of sectors to be read from the disc, read all sectors of the number of sectors on a disc during a first disc revolution, identify error sectors having a number of errors above a predetermined threshold, correct the data from the error sectors and write corrected data to the error sectors during a second disc revolution.

11. The disc drive storage system of claim 10 wherein the controller is further configured to track the number of errors occurring in each sector.

12. The disc drive storage system of claim 10 wherein the controller is further configured to generate a mask for the number of sectors, wherein the mask contains signals for each of the number of sectors based on whether the sector is an error sector or a non-error sector.

13. The disc drive storage system of claim 12 wherein the controller includes a disc controller operably coupled to the transducer to selectively read and write only the error sectors to the disc surface based on the mask.

14. The disc drive storage system of claim 12 wherein the mask is stored in the buffer memory.

15. The disc drive storage system of claim 10, wherein the disc controller is further configured to read data from only the error sectors during an intermediate disc revolution, occurring between the first and second disc revolutions.

16. The disc drive storage system of claim 10 wherein the controller further comprises an error correction code unit to correct the data from the error sectors.

17. The disc drive storage system of claim 10 wherein the controller is further configured to store the data from the error sectors in the buffer memory.

18. A disc drive storage system for storing information on a surface of a disc, comprising:

a transducer for reading and writing information to the disc surface;

and

means for correcting sectors identified as having a number of errors above a predetermined threshold.

19. The disc drive storage system of claim 18 and further comprising means for tracking errors occurring in the sectors and generating signals based on the errors.

20. The disc drive storage system of claim 19 and further comprising means for selectively reading and writing data from the disc surface based on the signals.