Data storage device employing variable size interleave written track segments

• US 9,281,009 B1
• Filed: 12/18/2014
• Issued: 03/08/2016
• Est. Priority Date: 12/18/2014
• Status: Active Grant

• Current Assignee: JP Morgan Chase Bank, N.A. (JP Morgan Chase & Co)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Banh, Thao Hieu, Chan, Tom S., Burton, Derrick E., Therrien, Michael J.
• Primary Examiner(s): Dinh, Tan X
• Application Number:
  US14/575,634
• Time in Patent Office: 446 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G11B 20/18 Error detection or correction; Testing , e.g. of drop-outs
• CPC Class Codes: G11B 20/1833 by adding special lists or symbols to the coded information G11B20/1806, G11B20/1866 take precedence
• CPC Class Codes: G11B 20/1866 by interleaving G11B20/1809 takes precedence
• CPC Class Codes: G11B 2020/1853 using a product code which has inner and outer parity symbols

Abstract

A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of data tracks. Data is encoded into a first number of codewords, and the first number of codewords are interleave written to a first segment of a first data track. Data is encoded into a second number of codewords, and the second number of codewords are interleave written to a second segment of the first data track. The first number of codewords is different than the second number of codewords, and a size of the first segment is different than a size of the second segment.

Claims

1. A data storage device comprising:

a disk comprising a plurality of data tracks;

a head; and

control circuitry configured to;

encode data into a first number of codewords;

interleave write the first number of codewords to a first segment of a first data track;

encode data into a second number of codewords; and

interleave write the second number of codewords to a second segment of the first data track;

wherein the first number is different than the second number and a size of the first segment is different than a size of the second segment.

2. The data storage device as recited in claim 1, wherein:

the first data track comprises an integer number N_sect of data sectors;

the first segment comprises a first integer L₀ of the data sectors; and

the second segment comprises a second integer L₁ of the data sectors.

3. The data storage device as recited in claim 2, wherein the second segment comprises one less data sector than the first segment.

4. The data storage device as recited in claim 3, wherein the control circuitry is further configured to compute L₀ according to:

5. The data storage device as recited in claim 4, wherein the first data track comprises an integer N_L0 of the first segments and an integer N_L1 of the second where:

6. The data storage device as recited in claim 5, wherein the control circuitry is further configured to compute L₀, N_L0 and N_L1 on the fly when executing a write command.

7. The data storage device as recited in claim 5, wherein the control circuitry is further configured to compute L₀, N_L0 and N_L1 on the fly when executing a read command.

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

encoding data into a first number of codewords;

interleave writing the first number of codewords to a first segment of a first data track on a disk;

encoding data into a second number of codewords; and

interleave writing the second number of codewords to a second segment of the first data track on the disk;

wherein the first number is different than the second number and a size of the first segment is different than a size of the second segment.

9. The method as recited in claim 8, wherein:

the first data track comprises an integer number N_sect of data sectors;

the first segment comprises a first integer L₀ of the data sectors; and

the second segment comprises a second integer L₁ of the data sectors.

10. The method as recited in claim 9, wherein the second segment comprises one less data sector than the first segment.

11. The method as recited in claim 10, further comprising computing L₀ according to:

12. The method as recited in claim 11, wherein the first data track comprises an integer N_L0 of the first segments and an integer N_L1 of the second segments where:

13. The method as recited in claim 12, further comprising computing L₀, N_L0 and N_L1 on the fly when executing a write command.

14. The method as recited in claim 12, further comprising computing L₀, N_L0 and N_L1 on the fly when executing a read command.