Storage control system with data management mechanism and method of operation thereof

• US 8,949,689 B2
• Filed: 06/11/2012
• Issued: 02/03/2015
• Est. Priority Date: 06/11/2012
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Smart Storage Systems Incorporated (Western Digital Corporation)
• Inventors: Ellis, Robert W.
• Primary Examiner(s): Bhatia, Ajay
• Assistant Examiner(s): GANDHI, DIPAKKUMAR B
• Application Number:
  US13/493,949
• Publication Number:
  US 20130332796A1
• Time in Patent Office: 967 Days
• Field of Search: None
• US Class Current: 714/763
• CPC Class Codes: G06F 11/1048 using arrangements adapted for a specific error detection or correction feature

Abstract

A method of operation of a storage control system includes: generating encoded data having a proportional data distribution for writing to a memory device; identifying a marginal block when an erase block is read from the memory device; and generating a marginal tag for the marginal block, the marginal tag having a non-proportional data distribution different from the proportional data distribution.

Claims

1. A method of operation of a storage control system comprising:

generating encoded data having a proportional data distribution for writing to a memory device;

identifying a marginal block when an erase block is read from the memory device;

generating a marginal tag for the marginal block, the marginal tag having a non-proportional data distribution different from the proportional data distribution;

storing the marginal tag in data pages of the marginal block; and

upon reading a data page in which the marginal tag has been stored, detecting that the data page has a non-proportional data distribution different from the proportional data distribution, and detecting that the data page is unusable and located in the marginal block in accordance with said detection of the non-proportional data distribution.

2. The method as claimed in claim 1 wherein:

generating the encoded data includes generating the encoded data having a data binary-zero distribution; and

generating the marginal tag includes generating the marginal tag having a tag binary-zero distribution different from the data binary-zero distribution.

3. The method as claimed in claim 1 wherein

storing the marginal tag includes storing the marginal tag in one or more data pages determined to be uncorrectable pages of the erase block.

4. The method as claimed in claim 1 further comprising:

generating a tag identifier for the marginal tag; and

writing the tag identifier to a tag page in the marginal block.

5. The method as claimed in claim 1 further comprising:

generating a tag correction code for the marginal block; and

correcting a tag correctable error in the marginal block with the tag correction code.

6. A method of operation of a storage control system comprising:

generating encoded data having a proportional data distribution for writing to a memory device;

identifying a marginal block based on a block error when an erase block is read from the memory device;

generating a marginal tag for the marginal block, the marginal tag having a non-proportional data distribution different from the proportional data distribution;

storing the marginal tag in data pages of the marginal block; and

upon reading a data page in which the marginal tag has been stored, detecting that the data page has a non-proportional data distribution different from the proportional data distribution, and detecting that the data page is unusable and located in the marginal block in accordance with said detection of the non-proportional data distribution.

7. The method as claimed in claim 6 wherein:

generating the encoded data includes generating the encoded data having a data binary-zero distribution; and

generating the marginal tag includes generating the marginal tag having a tag binary-zero distribution and a tag binary-one distribution, the tag binary-zero distribution different from the data binary-zero distribution; and

further comprising;

generating a read tag having a read binary-zero distribution and a read binary-one distribution, the read binary-zero distribution different from the tag binary-zero distribution, the read binary-one distribution different from the tag binary-one distribution.

8. The method as claimed in claim 6 wherein:

generating the encoded data includes generating the encoded data having a data binary-one distribution; and

generating the marginal tag includes generating the marginal tag having a lump pattern with a tag binary-one distribution different from the data binary-one distribution, the lump pattern having contiguous binary-zero digits and contiguous binary-one digits.

9. The method as claimed in claim 6 further comprising:

generating a contiguous sequence of a tag identifier for the marginal tag; and

writing the contiguous sequence of the tag identifier to a tag page in the marginal block.

10. The method as claimed in claim 6 further comprising:

generating a tag correction code with a tag correction rate of at least fifty percent for the marginal block; and

correcting a tag correctable error in the marginal block with the tag correction code.

11. A storage control system comprising:

a data generation module for generating encoded data having a proportional data distribution for writing to a memory device;

a block identification module for identifying a marginal block when an erase block is read from the memory device;

a tag generation module for;

generating a marginal tag for the marginal block, the marginal tag having a non-proportional data distribution different from the proportional data distribution;

storing the marginal tag in data pages of the marginal block; and

a tag detection module for detecting, after the storage control system reads a data page in which the marginal tag has been stored, that the data page has a non-proportional data distribution different from the proportional data distribution, and detecting that the data page is unusable and located in the marginal block in accordance with said detection of the non-proportional data distribution.

12. The system as claimed in claim 11 wherein:

the data generation module is for generating the encoded data having a data binary-zero distribution; and

the tag generation module is for generating the marginal tag having a tag binary-zero distribution different from the data binary-zero distribution.

13. The system as claimed in claim 11 wherein:

the data generation module is for generating the encoded data having a data binary-one distribution; and

the tag generation module is for generating the marginal tag having a lump pattern with a tag binary-one distribution different from the data binary-one distribution.

14. The system as claimed in claim 11 wherein:

the tag generation module is for generating a tag identifier for the marginal tag; and

further comprising;

a tag-writing module for writing the tag identifier to a tag page in the marginal block.

15. The system as claimed in claim 11 further comprising:

a code generation module for generating a tag correction code for the marginal block; and

a tag correction module for correcting a tag correctable error in the marginal block with the tag correction code.

16. The system as claimed in claim 11 wherein the block identification module is for identifying the marginal block based on a block error when the erase block is read from the memory device.

17. The system as claimed in claim 16 wherein:

the data generation module is for generating the encoded data having a data binary-zero distribution; and

the tag generation module is for generating the marginal tag having a tag binary-zero distribution and a tag binary-one distribution, the tag binary-zero distribution different from the tag binary-one distribution and the data binary-zero distribution; and

further comprising;

a tag detection module for generating a read tag having a read binary-zero distribution and a read binary-one distribution, the read binary-zero distribution different from the tag binary-zero distribution, the read binary-one distribution different from the tag binary-one distribution.

18. The system as claimed in claim 16 wherein:

the data generation module is for generating the encoded data having a data binary-one distribution; and

the tag generation module is for generating the marginal tag having a lump pattern with a tag binary-one distribution different from the data binary-one distribution, the lump pattern having contiguous binary-zero digits and contiguous binary-one digits.

19. The system as claimed in claim 16 wherein:

the tag generation module is for generating a contiguous sequence of a tag identifier for the marginal tag; and

further comprising;

a tag-writing module for writing the contiguous sequence of the tag identifier to a tag page in the marginal block.

20. The system as claimed in claim 16 further comprising:

a code generation module for generating a tag correction code with a tag correction rate of at least fifty percent for the marginal block; and

a tag correction module for correcting a tag correctable error in the marginal block with the tag correction code.