Solid state storage system for controlling reserved area and method of controlling the same

• US 8,370,680 B2
• Filed: 07/19/2010
• Issued: 02/05/2013
• Est. Priority Date: 12/24/2009
• Status: Active Grant

• Current Assignee: Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Original Assignee: SK Hynix Inc.
• Inventors: Kwak, Jeong Soon, Lee, Myung Suk, Kim, Kyeong Rho, Moon, Yang Gi
• Primary Examiner(s): Lottich, Joshua P
• Application Number:
  US12/839,325
• Publication Number:
  US 20110161727A1
• Time in Patent Office: 932 Days
• Field of Search: 714/6.11, 714/6.12, 714/6.13, 714/6.32, 714/710, 714/711
• US Class Current: 714/6.13
• CPC Class Codes: G06F 11/1662 the resynchronized component or unit being a persistent storage device re-synchronization of failed mirror storage G06F11/2082; rebuild or reconstruction of parity RAID storage G06F11/1008
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence

Abstract

A solid state storage system includes a flash memory region comprising a plurality of memory blocks and a plurality of replacement blocks corresponding to error-occurred blocks when errors occur in the memory blocks; and a memory controller configured to perform a control operation to replace the error-occurred blocks with the replacement blocks, wherein the error-occurred blocks comprise correctable blocks and uncorrectable blocks, and wherein the memory controller determines whether the error-occurred blocks are the correctable blocks or the uncorrectable blocks and controls zones of the replacement blocks, replaced in correspondence to the correctable blocks, to be allocated a plurality of times.

Claims

1. A solid state storage system comprising:

a flash memory region comprising a plurality of memory blocks and a plurality of replacement blocks corresponding to error-occurred blocks when errors occur in the memory blocks; and

a memory controller configured to perform a control operation to replace the error-occurred blocks with the replacement blocks,

wherein the error-occurred blocks comprise correctable blocks and uncorrectable blocks, and

wherein the memory controller determines whether the error-occurred blocks are the correctable blocks or the uncorrectable blocks and controls zones of the replacement blocks, replaced in correspondence to the correctable blocks, to be allocated a plurality of times.

2. The solid state storage system according to claim 1, wherein the memory controller establishes a plurality of pointers to separately control the zones of the replacement blocks by dividing the zones of the replacement blocks into zones to be replaced in correspondence to the correctable blocks and zones to be replaced in correspondence to the uncorrectable blocks.

3. The solid state storage system according to claim 2, wherein the plurality of pointers comprise:

a start pointer with a value that increases as a minimum value of logical addresses of the replacement blocks increases; and

an end pointer with a value that increases as a maximum value of the logical addresses of the replacement blocks decreases.

4. The solid state storage system according to claim 3, wherein, if the error-occurred blocks belong to the correctable blocks, replacement is made by allocating zones using the start pointer.

5. The solid state storage system according to claim 3, wherein, if the error-occurred blocks belong to the uncorrectable blocks, replacement is made by allocating zones using the end pointer.

6. The solid state storage system according to claim 3, wherein, when logical blocks designated by the start pointer and logical blocks designated by the end pointer are the same, the memory controller initializes the start pointer.

7. The solid state storage system according to claim 6, wherein the memory controller controls initialization of the start pointer for a logical block designated by the start pointer to correspond to a block with the minimum value of the logical addresses of the replacement blocks.

8. The solid state storage system according to claim 6, wherein, when logical blocks designated by the start pointer and logical blocks designated by the end pointer for a new correctable block are the same, the memory controller reallocates a logical block previously allocated by the start pointer.

9. A method for controlling a solid state storage system, comprising:

determining whether error-occurred blocks are correctable blocks or uncorrectable blocks;

allocating sequentially zones to blocks that correspond to logical addresses decreasing from a maximum value of logical addresses of replacement blocks when the error-occurred blocks belong to the uncorrectable blocks; and

allocating sequentially zones to blocks that correspond to logical addresses increasing from a minimum value of the logical addresses of the replacement blocks when the error-occurred blocks belong to the correctable blocks.

10. The method according to claim 9, wherein, when the error-occurred blocks belong to the uncorrectable blocks, a value of an end pointer is increased as a value of a logical address decreases from the maximum value of the logical addresses of the replacement blocks.

11. The method according to claim 9, wherein, when the error-occurred blocks belong to the correctable blocks, a value of a start pointer is increased as a value of a logical address increases from the minimum value of the logical addresses of the replacement blocks.

12. The method according to claim 11, wherein, when no zone for a new error-occurred block remains in the correctable blocks or in the replacement blocks, the start pointer is initialized.

13. The method according to claim 12, wherein, when no zone remains in the replacement blocks, logical blocks designated by the start pointer and the end pointer are the same.

14. The method according to claim 12, wherein initialization of the start pointer is controlled for a logical block designated by the start pointer to correspond to a block with the minimum value of the logical addresses of the replacement blocks.

15. The method according to claim 14, further comprising error checking after reallocating the block corresponding to the minimum value of the logical addresses and replacing the replacement block for the correctable block with the reallocated block.

16. The method according to claim 15, wherein, if an error occurs after the error checking, replacement is made by allocating a logical block that is designated by increasing a current value of the end pointer.

17. A storage device comprising:

a memory region comprising at least one memory block and at least one replacement block that is used to replace the at least one memory block when an error occurs in the memory block; and

a memory controller configured to perform a control operation to replace the at least one memory block with the at least one replacement block when the error occurs in the at least one memory block,

wherein the memory controller determines whether the at least one memory block is a correctable block or an uncorrectable block, the correctable block being a block that is correctable through an error correction algorithm based on data in the at least one memory block and the uncorrectable block being a block that is not correctable through the error correction algorithm, and controls a relative location of the replacement block replacing the correctable block, and

wherein the memory controller establishes a plurality of pointers to separately control the location of the replacement block.

18. The storage device according to claim 17, wherein the plurality of pointers comprise:

a start pointer with a value that increases as a minimum value of logical addresses of the at least one replacement block increases; and

an end pointer with a value that increases as a maximum value of the logical addresses of the at least one replacement block decreases.

19. The storage device according to claim 18, wherein, if the error-occurred block is the correctable block, replacement is made by identifying the location of the at least one replacement block using the start pointer.

20. The storage device according to claim 18, wherein, if the error-occurred block is the uncorrectable block, replacement is made by identifying the location of the at least one replacement block using the end pointer.