SYNCHRONIZED MAINTENANCE OPERATIONS IN A MULTI-BANK STORAGE SYSTEM

• US 20120084489A1
• Filed: 09/30/2010
• Published: 04/05/2012
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Sandisk Technologies Incorporated (Western Digital Corporation)
• Inventors: Gorobets, Sergey Anatolievich, Bennett, Alan David, Schroter, Charles Michael, Zilberman, Eugene
• Granted Patent: US 8,452,911 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 2212/7205 Cleaning, compaction, garbage collection, erase control

Abstract

A method and system for managing maintenance operations in a multi-bank non-volatile storage device is disclosed. The method includes receiving a data write command and associated data from a host system for storage in the non-volatile storage device and directing a head of the data write command to a first bank in the and a tail of the data write command to a second bank, where the head of the data write command only includes data having logical block addresses preceding logical block addresses of data in the tail of the data write command. When a status of the first bank delays execution of the data write command the controller executes a second bank maintenance procedure in the second bank while the data write command directed to the first and second banks is pending. The system includes a plurality of banks, where each bank may be associated with the same or different controllers, and the one or more controllers are adapted to execute the method noted above.

Claims

1. A method of managing maintenance operations in a non-volatile storage device, the method comprising:

in a non-volatile storage device having a controller and a plurality of banks of memory cells, wherein each of the plurality of banks is arranged in blocks of memory cells that are erasable together, the controller;

receiving a data write command and associated data from a host system for storage in the non-volatile storage device;

directing a head of the data write command to a first bank in the plurality of banks and a tail of the data write command to a second bank in the plurality of banks, wherein the head of the data write command comprises data having logical block addresses preceding logical block addresses of data in the tail of the data write command; and

executing a second bank maintenance procedure in the second bank while the data write command directed to the first and second banks is pending when a status of the first bank delays execution of the data write command.

2. The method of claim 1, wherein the status of the first bank comprises the first bank currently executing a first bank maintenance procedure and a buffer of the first bank being unable to store data associated with the head of the data write command.

3. The method of claim 2, further comprising executing the second bank maintenance procedure only while the first bank maintenance procedure is being executed.

4. The method of claim 1, wherein the first bank maintenance procedure comprises a data copy procedure.

5. The method of claim 4, wherein the data copy procedure comprises a garbage collection procedure.

6. A method of managing maintenance operations in a non-volatile storage device, the method comprising:

in a non-volatile storage device having a controller and a plurality of banks of memory cells, wherein each of the plurality of banks is arranged in blocks of memory cells that are erasable together, the controller;

receiving a data write command and associated data from a host system for storage in the non-volatile storage device;

directing the data write command to at least two banks of the plurality of banks to store the received data;

detecting for a next bank of the at least two banks a status of a first bank of the at least two banks; and

executing a second maintenance procedure in the next bank of the at least two banks when a data buffer for the first bank is full and the first bank is detected to be executing a first maintenance procedure while the data write command directed to the at least two banks is pending.

7. The method of claim 6, wherein executing the second maintenance procedure comprises executing the second maintenance procedure only while the first maintenance procedure is being executed.

8. The method of claim 7, wherein executing the first maintenance procedure comprises executing a first garbage collection procedure.

9. The method of claim 8, wherein executing the second maintenance procedure comprises executing a second garbage collection procedure.

10. The method of claim 6, wherein executing the second maintenance procedure comprises executing a different maintenance procedure than the first maintenance procedure.

11. The method of claim 8, wherein the second maintenance procedure comprises a non-copy procedure.

12. The method of claim 6, further comprising updating a status array in the non-volatile storage system with a current status of each of the plurality of banks, and wherein detecting for the next bank of the at least two banks the status of the first bank comprises the next bank accessing the status array.

13. The method of claim 12, wherein the next bank accessing the storage array comprises the next bank accessing time duration information for the first maintenance procedure, and wherein executing the second maintenance procedure comprises the next bank executing the second maintenance procedure for a time that does not exceed the accessed time duration information for the first maintenance procedure.

14. The method of claim 6, wherein each of the plurality of banks comprises a flash memory access engine and wherein detecting for the next bank of the at least two banks the status of the first bank comprises the next bank detecting a status of a flash memory access engine of the first bank to determine if the first bank is engaged in a maintenance operation.

15. A non-volatile memory device comprising:

non-volatile storage, the non-volatile storage having a plurality of banks of memory cells, wherein each of the plurality of banks is arranged in blocks of memory cells that are erasable together; and

a controller in communication with the plurality of banks of memory cells, the controller configured to;

receive a data write command and associated data from a host system for storage in the non-volatile storage system;

direct a head of the data write command to a first bank in the plurality of banks and a tail of the data write command to a second bank in the plurality of banks, wherein the head of the data write command comprises data having logical block addresses preceding logical block addresses of data in the tail of the data write command; and

execute a second bank maintenance procedure in the second bank while the data write command directed to the first and second banks is pending when a status of the first bank delays execution of the data write command.

16. The non-volatile memory device of claim 15, wherein the status of the first bank comprises the first bank currently executing a first bank maintenance procedure and a buffer of the first bank being unable to store data associated with the head of the data write command.

17. The non-volatile memory device of claim 16, wherein the controller is further configured to execute the second bank maintenance procedure only while the first bank maintenance procedure is being executed.

18. The non-volatile memory device of claim 15, wherein the first bank maintenance procedure comprises a data copy procedure.

19. The non-volatile memory device of claim 18, wherein the data copy procedure comprises a garbage collection procedure.

20. The non-volatile memory device of claim 15, further comprising a volatile memory having a status array containing a current status of each of the plurality of banks, and wherein the controller is further configured to determine the status of the first bank by accessing the status array.

21. The non-volatile memory device of claim 20, wherein the status array further comprises time duration information for the first bank maintenance procedure and wherein the controller is further configured to execute the second bank maintenance procedure for a time that does not exceed the time duration information for the first bank accessed from the status array.