Device controller for a memory device

• US 9,183,128 B2
• Filed: 02/23/2012
• Issued: 11/10/2015
• Est. Priority Date: 02/23/2011
• Status: Expired due to Fees

• Current Assignee: ST-Ericcson SA (Telefonaktiebolaget LM Ericsson)
• Original Assignee: ST-Ericcson SA (Telefonaktiebolaget LM Ericsson)
• Inventors: Das Purkayastha, Saugata
• Primary Examiner(s): Unelus, Ernest
• Application Number:
  US13/977,623
• Publication Number:
  US 20140025906A1
• Time in Patent Office: 1,356 Days
• Field of Search: 709/248, 710/61
• US Class Current: 1/1
• CPC Class Codes: G06F 12/023 Free address space management
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7207 management of metadata or control data

Abstract

The invention provides a method for controlling writing of data to a data storage card having a device controller and a storage medium. Particularly, the device controller receives a meta data synchronization disable command and in response, enters a first mode. In the first mode, the device controller does not synchronize meta data related to a data write request to write the data to the storage medium, leaving corresponding unsynchronized meta data. The device controller receives a data write request to write the data, and in response, effects the data write request such that the data is written to the storage medium. However, the meta data related to the data write request is not synchronized to the storage medium. Other aspects provide a corresponding device controller and software/firmware.

Claims

1. A method for controlling the writing of data to a data storage card having a device controller and a storage medium, the method performed at the device controller and comprising:

enabling meta data synchronization at the data storage card;

receiving a meta data synchronization disable command;

entering a first mode responsive to receiving the meta data synchronization disable command, wherein in the first mode, the device controller does not synchronize meta data associated with a data write request by not writing the meta data to a predefined synchronization location in the storage medium, thereby leaving corresponding unsynchronized meta data;

receiving the data write request to write the data; and

writing the data to the storage medium in response to receiving the data write request, wherein the meta data associated with the data write request is not synchronized to the storage medium.

2. The method of claim 1 wherein enabling meta data synchronization at the data storage card comprises:

receiving a meta data synchronization enable command; and

entering a second mode in response to receiving the meta data synchronization enable command, wherein in the second mode, the device controller synchronizes the unsynchronized meta data in response to the meta data synchronization enable command, or following the receipt of a subsequent data write request, by writing the meta data to the predefined synchronization location in the storage medium.

3. The method of claim 2 wherein the device controller remains in the second mode after synchronizing the unsynchronized meta data, and wherein meta data related to a subsequent data write request is synchronized to the storage medium as part of writing the data to the storage medium responsive to the subsequent data write request.

4. The method of claim 2 further comprising:

receiving the meta data synchronization enable command while the device controller is in the first mode; and

synchronizing the unsynchronized meta data to the storage medium in response to receiving the meta data synchronization enable command.

5. The method of claim 1 wherein the meta data synchronization disable command is sent to the device controller by a host controller.

6. The method of claim 2 wherein the meta data synchronization enable command is sent to the device controller by a host controller.

7. The method of claim 1 further comprising synchronizing the meta data to free up storage medium blocks while the device controller is in the first mode.

8. The method of claim 1 further comprising synchronizing meta data related to storage medium bad blocks while the device controller is in the first mode as part of storage medium bad block management.

9. The method of claim 1 further comprising:

receiving an explicit meta data synchronization command from a host controller; and

synchronizing the unsynchronized meta data in response to receiving the explicit meta data synchronization command.

10. The method of claim 9 further comprising remaining in the first mode responsive to receiving the explicit meta data synchronization command.

11. A data storage card device controller for controlling the writing of data to a data storage card having a storage medium, the device controller configured to:

enable meta data synchronization;

receive a meta data synchronization disable command;

enter a first mode in response to receiving the meta data synchronization disable command, wherein in the first mode, the device controller does not synchronize meta data related to a data write request by not writing the meta data to a predefined synchronization location in the storage medium, thereby leaving corresponding unsynchronized meta data;

receive the data write request to write the data; and

write the data to the storage medium in response to receiving the data write request, wherein the meta data associated the data write request is not synchronized to the storage medium.

12. The data storage card device controller of claim 11 wherein to enable meta data synchronization, the data storage card device controller is further configured to:

receive a meta data synchronization enable command; and

enter a second mode in response to receiving the meta data synchronization enable command, wherein in the second mode, the device controller synchronizes the unsynchronized meta data to the storage medium, either in response to the meta data synchronization enable command, or following a subsequent data write request, by writing the meta data to the predefined synchronization location in the storage medium.

13. The data storage card device controller of claim 12 wherein the device controller is further configured to:

remain in the second mode after synchronizing the unsynchronized meta data; and

synchronize meta data related to a subsequent data write request to the storage medium as part of effecting the subsequent data write request.

14. The data storage card device controller of claim 12 wherein the device controller is further configured to:

receive the meta data synchronization enable command while in the first mode; and

synchronize the unsynchronized meta data to the storage medium in response to receiving the meta data synchronization enable command.

15. The data storage card device controller of claim 11 wherein while the device controller is in the first mode, the device controller is further configured to synchronize meta data related to freeing up storage medium blocks as part of freeing up the storage medium blocks.

16. The data storage card device controller of claim 11 wherein, while the device controller is in the first mode, the device controller is further configured to synchronize the meta data related to storage medium bad blocks while managing a storage medium bad block.

17. The data storage card device controller of claim 11 further configured to receive an explicit meta data synchronization command and synchronize the unsynchronized meta data in response.

18. The data storage card device controller of claim 17 wherein the explicit meta data synchronization command causes the device controller to remain in the first mode.

19. The data storage card device controller of claim 12 wherein at least one of the meta data synchronization enable command and the meta data synchronization disable command is received from a host controller.

20. A computer program product comprising:

a non-transitory computer-readable medium configured to store instructions that, when executed by a data storage card device controller, configures the data storage card device controller to;

enable meta data synchronization at the data storage card;

receive a meta data synchronization disable command;

enter a first mode responsive to receiving the meta data synchronization disable command, wherein in the first mode, the device controller does not synchronize meta data associated with a data write request by not writing the meta data to a predefined synchronization location in the storage medium, thereby leaving corresponding unsynchronized meta data;

receive the data write request to write the data; and

write the data to the storage medium in response to receiving the data write request, wherein the meta data associated with the data write request is not synchronized to the storage medium.