Granted Patent B2

US 10,289,323 · App. 16/017,950 · Granted May 14, 2019

Abstract

Claims (73)

1. A method, comprising:

upon experiencing a shutdown, powering up a memory device;

determining a state of a recovery flag in a boot block, wherein the recovery flag is set upon the memory device experiencing an abrupt shutdown;

scanning a log block to determine a last good page that was processed by the memory device;

determining a state of a graceful shutdown flag;

applying metadata stored in a control block for rebuilding data in a DRAM based on the recovery flag being set and the graceful shutdown flag being reset;

configuring the DRAM; and

enabling access to the memory device to continue read/write operations.

2. The method of claim 1 , further comprising regenerating new metadata in the DRAM based on the recovery flag being reset and the graceful shutdown flag being reset.

3. The method of claim 1 , further comprising generating metadata based on the graceful shutdown flag being set.

4. The method of claim 1 , wherein metadata stored in a control block includes one or more of XOR parity bins, CVD tables, and flash translation layer logical block address tables from previously-flushed metadata.

5. The method of claim 1 , wherein scanning a log block is performed by firmware in a controller associated with the memory device.

6. The method of claim 1 , wherein the graceful shutdown flag is set by completion of NAND die read/write operations.

7. The method of claim 1 , wherein rebuilding data in the DRAM includes checking, by a controller, the recovery flag and using a pointer in the recovery flag to access metadata stored in a control block.

8. A memory device, comprising:

a plurality of non-volatile memory elements configured to process a plurality of read/write operations;

a volatile memory element configured to store metadata of the memory device;

one or more temperature detectors configured to measure temperatures of the plurality of non-volatile memory elements;

a controller configured to:

acquire the temperatures of the plurality of non-volatile memory elements from the one or more temperature detectors at a first frequency; and

upon determining that the temperature of a first one of the plurality of non-volatile memory elements is above a first threshold:

activate thermal throttling for the plurality of non-volatile memory elements; and

flush the metadata from the volatile memory element to the plurality of non-volatile memory elements; and

means for recovering metadata after an abrupt shutdown, comprising:

means for powering up the memory device upon experiencing a shutdown;

means for determining a state of a recovery flag in a boot block, wherein the recovery flag is set upon the memory device experiencing an abrupt shutdown;

means for scanning a log block to determine a last good page that was processed by the memory device;

means for determining a state of a graceful shutdown flag;

means for applying metadata stored in a control block for rebuilding data in a DRAM based on the recovery flag being set and the graceful shutdown flag being reset;

means for configuring the DRAM; and

means for enabling access to the memory device to continue read/write operations.

9. The memory device of claim 8 , wherein the memory device comprises a Solid State Drive (SSD).

10. The memory device of claim 8 , wherein each of the plurality of non-volatile memory elements comprises a NAND die.

11. The memory device of claim 8 , wherein the volatile memory element comprises a random-access memory.

12. The memory device of claim 8 , wherein the one or more temperature detectors are attached to the plurality of non-volatile memory elements.

13. The memory device of claim 8 , wherein the controller comprises a NAND controller.

14. A controller, comprising:

a processor;

a memory containing a program that, when executed on the processor, performs an operation, the operation comprising:

acquiring temperatures of a plurality of non-volatile memory elements in a memory device from one or more temperature detectors at a first frequency; and

upon determining that the temperature of a first one of the plurality of non-volatile memory elements is above a first threshold:

activating thermal throttling for the plurality of non-volatile memory elements; and

flushing metadata of the memory device from a volatile memory element in the memory device to the plurality of non-volatile memory elements; and

means for recovering metadata after an abrupt shutdown, comprising:

means for powering up the memory device upon experiencing a shutdown;

means for determining a state of a recovery flag in a boot block, wherein the recovery flag is set upon the memory device experiencing an abrupt shutdown;

means for scanning a log block to determine a last good page that was processed by the memory device;

means for determining a state of a graceful shutdown flag;

means for applying metadata stored in a control block for rebuilding data in a DRAM based on the recovery flag being set and the graceful shutdown flag being reset;

means for configuring the DRAM; and

means for enabling access to the memory device to continue read/write operations.

15. The controller of claim 14 , wherein flushing metadata of the memory device comprises flushing the metadata from the volatile memory element to a plurality of control blocks in the plurality of non-volatile memory elements.

16. The controller of claim 14 , further configured to set a status flag indicating metadata is present in a plurality of control blocks.

17. The controller of claim 14 , further configured to set a status flag in a boot block in the plurality of non-volatile memory elements.

18. The controller of claim 14 , further configured to set a status flag after successfully flushing the metadata.

19. A memory device, comprising:

a plurality of non-volatile memory elements configured to process a plurality of read/write operations;

a volatile memory element configured to store metadata of the memory device;

a controller coupled to the plurality of non-volatile memory elements and coupled to the volatile memory element; and

means for recovering metadata after an abrupt shutdown, comprising:

means for powering up the memory device upon experiencing a shutdown;

means for determining a state of a recovery flag in a boot block, wherein the recovery flag is set upon the memory device experiencing an abrupt shutdown;

means for scanning a log block to determine a last good page that was processed by the memory device;

means for determining a state of a graceful shutdown flag;

means for applying metadata stored in a control block for rebuilding data in a DRAM based on the recovery flag being set and the graceful shutdown flag being reset;

means for configuring the DRAM; and

means for enabling access to the memory device to continue read/write operations.

20. The memory device of claim 19 , wherein the memory device comprises a Solid State Drive (SSD).

21. The memory device of claim 19 , wherein each of the plurality of non-volatile memory elements comprises a NAND die.

22. The memory device of claim 19 , wherein the volatile memory element comprises a random-access memory.

23. The memory device of claim 19 , wherein the recovery flag includes a pointer pointing to an address in volatile memory storing metadata flushed in a cycle immediately prior to the abrupt shutdown.

24. The memory device of claim 19 , wherein the controller comprises a NAND controller.

25. The memory device of claim 19 , further comprising means for regenerating new metadata in DRAM whenever the recovery flag is reset and the graceful shutdown flag is reset.

Assignments (10)