METHOD FOR PERFORMING BLOCK MANAGEMENT, AND ASSOCIATED MEMORY DEVICE AND CONTROLLER THEREOF

• US 20120079168A1
• Filed: 05/25/2011
• Published: 03/29/2012
• Est. Priority Date: 09/27/2010
• Status: Active Grant

• Current Assignee: Silicon Motion Incorporated Taiwan (Silicon Motion)
• Original Assignee: Silicon Motion Incorporated Taiwan (Silicon Motion)
• Inventors: Shen, Yang-Chih, Chou, Po-Sheng, Chang, Ching-Chin
• Granted Patent: US 8,949,507 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7208 Multiple device management, e.g. distributing data over multiple flash devices
• CPC Class Codes: G11C 2029/0409 Online test
• CPC Class Codes: G11C 29/82 for EEPROMs
• CPC Class Codes: G11C 29/883 using a single defective memory device with reduced capacity, e.g. half capacity

Abstract

A method for performing block management is provided. The method is applied to a controller of a Flash memory having multiple channels. The Flash memory includes a plurality of blocks respectively corresponding to the channels. The method includes: temporarily storing at least one index of at least one good block that is not grouped into any meta block into a spare good block table, where the good block is a block that is not determined as a bad block within the plurality of blocks; and when it is detected that a specific block corresponding to a specific channel within blocks currently grouped into meta blocks is a bad block, dynamically updating the spare good block table for use of block management. In particular, when needed, the good block is utilized for replacing a block grouped into a meta block. An associated memory device and a controller thereof are also provided.

Claims

1. A method for performing block management, the method being applied to a controller of a Flash memory having multiple channels, the Flash memory comprising a plurality of blocks respectively corresponding to the channels, the method comprising:

temporarily storing at least one index of at least one good block that is not grouped into any meta block into a spare good block table, wherein the good block is a block that is not determined as a bad block within the plurality of blocks; and

when it is detected that a specific block corresponding to a specific channel within blocks currently grouped into meta blocks is a bad block, dynamically updating the spare good block table for use of block management.

2. The method of claim 1, wherein when needed, the good block is utilized for replacing a block grouped into a meta block.

3. The method of claim 1, further comprising:

when it is detected that the specific block corresponding to the specific channel is a bad block and the spare good block table indicates that a good block corresponding to the specific channel exists, dynamically replacing the specific block with the good block corresponding to the specific channel.

4. The method of claim 3, wherein the step of dynamically updating the spare good block table for use of block management further comprises:

when dynamically replacing the specific block with the good block corresponding to the specific channel, removing an index of the good block corresponding to the specific channel from the spare good block table.

5. The method of claim 1, wherein the step of dynamically updating the spare good block table for use of block management further comprises:

when it is detected that the specific block corresponding to the specific channel is a bad block, temporarily storing at least one index of at least one other block within a meta block to which the specific block belongs into the spare good block table.

6. The method of claim 1, further comprising:

storing a previous version of the spare good block table into the Flash memory, and storing a copy version of the spare good block table into a buffer of the controller, for use of dynamically updating the spare good block table; and

storing a latest version of the spare good block table within the buffer into the Flash memory, in order to replace the previous version of the spare good block table.

7. The method of claim 1, wherein the at least one index represents at least one physical address, and/or the at least one index corresponds to at least one physical address.

8. A memory device, comprising:

a Flash memory having multiple channels, wherein the Flash memory comprises a plurality of blocks respectively corresponding to the channels; and

a controller arranged to access the Flash memory and manage the plurality of blocks, wherein the controller temporarily stores at least one index of at least one good block that is not grouped into any meta block into a spare good block table, wherein the good block is a block that is not determined as a bad block within the plurality of blocks;

wherein when it is detected that a specific block corresponding to a specific channel within blocks currently grouped into meta blocks is a bad block, the controller dynamically updates the spare good block table for use of block management.

9. The memory device of claim 8, wherein when needed, the good block is utilized for replacing a block grouped into a meta block.

10. The memory device of claim 8, wherein when it is detected that the specific block corresponding to the specific channel is a bad block and the spare good block table indicates that a good block corresponding to the specific channel exists, the controller dynamically replaces the specific block with the good block corresponding to the specific channel.

11. The memory device of claim 10, wherein when dynamically replacing the specific block with the good block corresponding to the specific channel, the controller removes an index of the good block corresponding to the specific channel from the spare good block table.

12. The memory device of claim 8, wherein when it is detected that the specific block corresponding to the specific channel is a bad block, the controller temporarily stores at least one index of at least one other block within a meta block to which the specific block belongs into the spare good block table.

13. The memory device of claim 8, wherein the controller stores a previous version of the spare good block table into the Flash memory, and stores a copy version of the spare good block table into a buffer of the controller, for use of dynamically updating the spare good block table;

and the controller stores a latest version of the spare good block table within the buffer into the Flash memory, in order to replace the previous version of the spare good block table.

14. The memory device of claim 8, wherein the at least one index represents at least one physical address, and/or the at least one index corresponds to at least one physical address.

15. A controller of a memory device, the controller being utilized for accessing a Flash memory having multiple channels, the Flash memory comprising a plurality of blocks respectively corresponding to the channels, the controller comprising:

a read only memory (ROM) arranged to store a program code; and

a microprocessor arranged to execute the program code to control the access to the Flash memory and manage the plurality of blocks, wherein the controller that executes the program code by utilizing the microprocessor temporarily stores at least one index of at least one good block that is not grouped into any meta block into a spare good block table, and the good block is a block that is not determined as a bad block within the plurality of blocks;

wherein when it is detected that a specific block corresponding to a specific channel within blocks currently grouped into meta blocks is a bad block, the controller that executes the program code by utilizing the microprocessor dynamically updates the spare good block table for use of block management.

16. The controller of claim 15, wherein when it is detected that the specific block corresponding to the specific channel is a bad block and the spare good block table indicates that a good block corresponding to the specific channel exists, the controller that executes the program code by utilizing the microprocessor dynamically replaces the specific block with the good block corresponding to the specific channel.

17. The controller of claim 15, wherein when it is detected that the specific block corresponding to the specific channel is a bad block, the controller that executes the program code by utilizing the microprocessor temporarily stores at least one index of at least one other block within a meta block to which the specific block belongs into the spare good block table.

18. The controller of claim 15, wherein the controller that executes the program code by utilizing the microprocessor stores a previous version of the spare good block table into the Flash memory, and stores a copy version of the spare good block table into a buffer of the controller, for use of dynamically updating the spare good block table;

and the controller that executes the program code by utilizing the microprocessor stores a latest version of the spare good block table within the buffer into the Flash memory, in order to replace the previous version of the spare good block table.

19. A method for performing block management, the method being applied to a controller of a Flash memory having multiple channels, the Flash memory comprising a plurality of blocks respectively corresponding to the channels, erasing a single block within the blocks of the Flash memory being achievable, the method comprising:

establishing a meta block, wherein the meta block comprises blocks respectively belonging to different channels, and the controller erases the Flash memory with the meta block being a minimum erasure unit; and

according to damage statuses of the blocks within the meta block, updating block composition of the meta block or updating a damage status of the meta block.

20. The method of claim 19, wherein the step of updating the block composition of the meta block further comprises:

when it is detected that a block belonging to a first channel within the meta block is determined as a bad block, replacing the bad block with a good block belonging to the first channel.