Nonvolatile memory system and management method for nonvolatile memory

Abstract

A nonvolatile memory system includes a nonvolatile memory and a controller. The controller is configured to manage the nonvolatile memory based on management information. The management information of the controller includes a basic table for collectively managing a plurality of blocks and differential information between the blocks. The controller is operable to manage the blocks collectively with the basic table and manage different portions of the blocks within the collected range using the differential information.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view illustrating a subject to be solved by the present invention;

FIG. 2 is a block diagram showing an example of a configuration of a nonvolatile memory system to which the present invention is applied;

FIG. 3 is a diagrammatic view illustrating a concept of a memory region of a memory unit shown in FIG. 2;

FIG. 4 is a diagrammatic view illustrating an example of an ordinary flash management table;

FIG. 5 is a diagrammatic view illustrating a basic table and a differential information table included in management information used in the nonvolatile memory system;

FIG. 6 is a diagrammatic view illustrating a manner of conversion from a logical address into a virtual block address and conversion of a virtual block address into an address to be used upon accessing to a memory bank in the nonvolatile memory system;

FIG. 7 is a diagrammatic view illustrating a physical address to physical address conversion table wherein all virtual block addresses and access addresses of memory banks are coordinated with each other;

FIG. 8 is a diagrammatic view illustrating a physical address to physical address conversion table wherein virtual block addresses at which replacement of a block occurs and access addresses of the banks are coordinated with each other;

FIG. 9 is a diagrammatic view illustrating a physical address to physical address conversion table wherein a virtual block address of a block to be treated as a failed block and access addresses of the banks are coordinated with each other;

FIG. 10 is a diagrammatic view illustrating a logical to physical-physical to physical conversion table wherein a flag of 1 bit is added in a physical address field of a logical to physical table;

FIG. 11 is a diagrammatic view illustrating a logical to physical-physical to physical conversion table wherein an index to a corresponding table is added to a physical address field with regard to which access address exchange of a logical address to physical address conversion table is to be performed;

FIG. 12 is a diagrammatic view illustrating an example of a replacement process for a failed block which uses differential information executed by the nonvolatile memory system;

FIG. 13 is a diagrammatic view illustrating an example of the differential information used in the replacement process for a failed block; and

FIG. 14 is a flow chart illustrating an address exchange flow executed by the nonvolatile memory system where the differential information is used.

Claims

1. A nonvolatile memory system, comprising: a nonvolatile memory; anda controller configured to manage said nonvolatile memory based on management information;the management information of said controller including a basic table for collectively managing a plurality of blocks and differential information between the blocks;said controller being operable to manage the blocks collectively with the basic table and manage different portions of the blocks within the collected range using the differential information.

2. The nonvolatile memory system according to claim 1, wherein said controller replaces one or more of the collected blocks with another block or blocks using the differential information.

3. The nonvolatile memory system according to claim 2, wherein the replacement is performed within a range of a bank, a chip or a partial region.

4. The nonvolatile memory system according to claim 2, wherein the replacement is performed within a range which extends across chips, across banks or across partial regions.

5. The nonvolatile memory system according to claim 1, wherein said nonvolatile memory has a plurality of banks, and said controller can perform accessing for each of the banks based on an address and collects a plurality of blocks of different ones of the blocks having a same bank internal address across the banks.

6. The nonvolatile memory system according to claim 1, wherein said nonvolatile memory includes a plurality of nonvolatile memory sections formed on different chips from each other, and said controller can perform accessing for each of the chips based on an address and collects a plurality of blocks of the chips having a same address across the chips.

7. The nonvolatile memory system according to claim 1, wherein said controller collects a plurality of blocks having a same partial address between a plurality of partial regions.

8. The nonvolatile memory system according to claim 1, wherein said controller includes a physical address to physical address conversion table for block replacement as the differential information.

9. The nonvolatile memory system according to claim 8, wherein said controller sets a flag to an object of the physical address to physical address conversion on a logical address to physical address conversion table which is used as the basic table.

10. The nonvolatile memory system according to claim 9, wherein said controller adds an index to a conversion table to a block of an object of the physical address to physical address conversion on the logical address to physical address conversion table which is used as the basic table.

11. The nonvolatile memory system according to claim 1, wherein said controller collectively manages a plurality of blocks and exchanges an access to a failed block into an access to another address.

12. The nonvolatile memory system according to claim 2, wherein said controller collectively manages a plurality of blocks and exchanges an access to a failed block into an access to another address.

13. A management method for a nonvolatile memory for managing accessing to the nonvolatile memory, wherein: management information to be used for managing the nonvolatile memory includes a basic table for collectively managing a plurality of blocks and differential information between the blocks, andthe blocks are managed collectively with the basic table whiledifferent portions of the blocks are managed within the collected range using the differential information.