Storage device and method for performing a self-refresh operation

Patent metadata

Field	Value
Publication number	US-9269451-B2
Application number	US-201414532611-A
Country	US
Kind code	B2
Filing date	Nov 4, 2014
Priority date	May 27, 2014
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

A storage device and method for performing a self-refresh operation are disclosed. In one embodiment, a storage device determines that the self-refresh operation needs to be performed. In response to that determination, the storage device performs the self-refresh operation by reading data from the memory and writing the data back to the memory without transferring the data outside of the storage device.

First claim

What is claimed is:

1. A method for performing a self-refresh operation in a storage device, the method comprising:
performing the following in a storage device after the storage device is powered by a host, wherein the storage device has a non-volatile memory:
determining whether to perform a self-refresh operation on data that was stored in the non-volatile memory before the storage device was powered by the host; and
in response to determining to perform the self-refresh operation, performing the self-refresh operation internally in the storage device by reading the data from the non-volatile memory of the storage device and writing the data back to the non-volatile memory of the storage device, wherein the storage device only needs to receive power from the host to perform the self-refresh operation.

2. The method of claim 1 further comprising:
storing a state of the self-refresh operation, so the self-refresh operation can resume if interrupted.

3. The method of claim 1 , wherein the storage device determines whether to perform the self-refresh operation by analyzing a time of a previous write of the data.

4. The method of claim 1 , wherein the storage device determines to perform the self-refresh operation in response to receiving a command to perform the self-refresh operation.

5. The method of claim 4 , wherein the command is generated by activation of a user input element on the storage device.

6. The method of claim 4 , wherein the command is received from the host.

7. The method of claim 6 , wherein the host is a docking station.

8. The method of claim 1 , wherein data is read from all valid, written logical addresses in the non-volatile memory.

9. The method of claim 1 , wherein only data that is older than a threshold age is read from the non-volatile memory.

10. A method for performing a self-refresh operation in a storage device, the method comprising:
performing the following in a storage device having a memory:
determining that a self-refresh operation needs to be performed; and
in response to determining that the self-refresh operation needs to be performed, performing the self-refresh operation by reading data from the memory and writing the data back to the memory without transferring the data outside of the storage device;

wherein the data is written back to a portion of the memory that is less used than the portion where the data was read from.

11. The method of claim 1 further comprising providing a status of the self-refresh operation.

12. The method of claim 1 , wherein the storage device comprises a controller on the same substrate as the memory.

13. The method of claim 1 , wherein the storage device is removably connectable to the host.

14. The method of claim 13 , wherein the storage device is a universal serial bus (USB) drive.

15. The method of claim 1 , wherein the storage device is embedded in the host.

16. A storage device comprising:
a non-volatile memory; and
a controller in communication with the non-volatile memory, wherein the controller is configured to perform the following after the storage device is powered by a host:
determine whether to perform a self-refresh operation on data that was stored in the non-volatile memory before the storage device was powered by the host; and
in response to determining to perform the self-refresh operation, perform the self-refresh operation internally in the storage device by reading the data from the non-volatile memory of the storage device and writing the data back to the non-volatile memory of the storage device, wherein the storage device only needs to receive power from the host to perform the self-refresh operation.

17. The storage device of claim 16 , wherein the controller is further configured to store a state of the self-refresh operation, so the self-refresh operation can resume if interrupted.

18. The storage device of claim 16 , wherein the controller is configured to determine whether to perform the self-refresh operation by analyzing a time of a previous write of the data.

19. The storage device of claim 16 , wherein the controller determines to perform the self-refresh operation in response to receiving a command to perform the self-refresh operation.

20. The storage device of claim 19 , wherein the command is generated by activation of a user input element on the storage device.

21. The storage device of claim 19 , wherein the command is received from the host.

22. The storage device of claim 19 , wherein the host is a docking station.

23. The storage device of claim 16 , wherein data is read from all valid, written logical addresses in the non-volatile memory.

24. The storage device of claim 16 , wherein only data that is older than a threshold age is read from the non-volatile memory.

25. A storage device comprising:
a memory; and
a controller in communication with the memory, wherein the controller is configured to:
determine that a self-refresh operation needs to be performed; and
in response to determining that the self-refresh operation needs to be performed, perform the self-refresh operation by reading data from the memory and writing the data back to the memory without transferring the data outside of the storage device;

wherein the data is written back to a portion of the memory that is less used than the portion where the data was read from.

26. The storage device of claim 16 , wherein the controller is further configured to provide a status of the self-refresh operation.

27. The storage device of claim 16 , wherein the controller is on the same substrate as the memory.

28. The storage device of claim 16 , wherein the storage device is removably connectable to the host.

29. The storage device of claim 28 , wherein the storage device is a universal serial bus (USB) drive.

30. The storage device of claim 16 , wherein the storage device is embedded in the host.

Assignees

• Sandisk Technologies Inc

Inventors

• Ellis Robert W

Classifications

• G11C16/3431

  Circuits or methods to detect disturbed nonvolatile memory cells, e.g. which still read as programmed but with threshold less than the program verify threshold or read as erased but with threshold greater than the erase verify threshold, and to reverse the disturbance via a refreshing programming or erasing step · CPC title

• G11C11/5642

  Sensing or reading circuits; Data output circuits · CPC title

• G11C11/5628

  Programming or writing circuits; Data input circuits · CPC title

• G11C16/3418 Primary

  Disturbance prevention or evaluation; Refreshing of disturbed memory data · CPC title