SYSTEM AND METHOD FOR UTILIZATION OF A DATA BUFFER IN A STORAGE DEVICE

• US 20170123991A1
• Filed: 10/28/2015
• Published: 05/04/2017
• Est. Priority Date: 10/28/2015
• Status: Abandoned Application

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Sandisk Technologies Incorporated (Western Digital Corporation)
• Inventors: Sela, Rotem, Sapir, Miki, Shaharabany, Amir, Oshinsky, Hadas, Marcu, Alon, Perry, Nir
• Application Number:
  US14/925,334
• Publication Number:
  US 20170123991A1
• Time in Patent Office: Days
• CPC Class Codes: G06F 11/0793 Remedial or corrective actions recovery from an exception in an instruction pipeline G06F9/3861; by retry G06F11/1402; for recovering from a failure of a protocol instance or entity H04L69/40
• CPC Class Codes: G06F 12/0207 with multidimensional access, e.g. row/column, matrix
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/0868 Data transfer between cache memory and other subsystems, e.g. storage devices or host systems
• CPC Class Codes: G06F 2212/1016 Performance improvement
• CPC Class Codes: G06F 2212/1024 Latency reduction
• CPC Class Codes: G06F 2212/202 Non-volatile memory
• CPC Class Codes: G06F 2212/281 Single cache
• CPC Class Codes: G06F 2212/313 In storage device
• CPC Class Codes: G06F 2212/7203 Temporary buffering, e.g. using volatile buffer or dedicated buffer blocks
• CPC Class Codes: G11C 16/102 External programming circuits, e.g. EPROM programmers; In-circuit programming or reprogramming; EPROM emulators

Abstract

Systems and methods for managing a data buffer of a non-volatile memory system are disclosed. The method may include a controller of a storage system retrieving host data, storing the retrieved data in a data buffer and transferring the data to a non-volatile memory. The controller may then overwrite the retrieved data in the data buffer as soon as the retrieved data has been transferred to the non-volatile memory die but prior to sending a command to program that data to the non-volatile memory array of the non-volatile memory. The system includes a non-volatile memory with a plurality of data latches and a non-volatile memory array, a data buffer and a controller configured to free the data buffer for receiving new data as soon as the prior data is transferred to the data latches and prior to any indication on success of programming prior data to the non-volatile memory array.

Claims

1. A data storage system comprising:

a non-volatile memory having a plurality of data latches and a non-volatile memory array;

a volatile memory with a data buffer; and

a controller having, or cooperatively coupled with, the volatile memory and in communication with the non-volatile memory, wherein the controller is configured to;

request, from a host in communication with the data storage system, first data associated with a pending host command;

write to the data buffer in the volatile memory the first data received from the host;

copy the first data from the data buffer to the plurality of data latches;

request additional data from the host; and

write the additional data to the data buffer prior to verifying that the first data was successfully written from the plurality of latches to the non-volatile memory array, wherein writing the additional data overwrites at least some of the first data in the data buffer and wherein the verifying lags behind the overwriting.

2. The data storage system of claim 1, wherein the controller is configured to request the additional data from the host and overwrite at least some of the first data prior to sending a program command to the non-volatile memory to program the first data from the plurality of data latches into the non-volatile memory array.

3. The data storage system of claim 1, wherein the first data and the additional data are associated with a same host command.

4. The data storage system of claim 1, wherein the non-volatile memory comprises a silicon substrate and a plurality of memory cells forming a monolithic three-dimensional structure, wherein at least one portion of the memory cells is vertically disposed with respect to the silicon substrate.

5. The data storage system of claim 1, wherein the pending host command comprises a host write command.

6. The data storage system of claim 1, wherein the controller is further configured to, in response to receiving an indication of a write failure relating to the first data, re-request the first data from the host and, upon receipt of the re-requested first data at the data buffer, write the re-requested first data from the data buffer to the non-volatile memory.

7. The data storage system of claim 1, further comprising a data buffer management table in the controller, the data buffer management table containing information on data stored in the data buffer;

and

wherein the controller is further configured to, in response to receiving an indication of a write failure relating to the first data;

determine from the data buffer management table whether the first data is valid in the data buffer; and

when the first data is determined to be valid in the data buffer, retry a write of the first data from the data buffer into the non-volatile memory.

8. The data storage system of claim 7, wherein the controller is further configured to, when the data buffer does not contain valid first data, re-request the first data from the host and, upon receipt of the re-requested first data at the data buffer, write the re-requested first data from the data buffer to the non-volatile memory.

9. The data storage system of claim 1, wherein the controller is further configured to:

release the data buffer after copying the first data to the plurality of data latches and prior to verifying that the first data was successfully written to the non-volatile memory array.

10. The data storage system of claim 9, wherein to release the data buffer the controller is configured to update a data buffer management table in the controller to reflect that there is no valid data in the data buffer.

11. The data storage system of claim 9, wherein the controller is further configured to, in response to receiving an indication of a write failure relating to the first data, re-request the first data from the host and, upon receipt of the re-requested first data at the data buffer, write the first data from the data buffer to the non-volatile memory.

12. A method of managing data in a data storage system in communication with a host, the method comprising the storage system:

requesting data associated with a pending host command from a memory outside of the data storage system;

storing the data in a data buffer in volatile memory in the data storage system;

copying the data from the data buffer to non-volatile memory in the data storage system; and

prior to verifying that the data retrieved from the data buffer in the data storage system was successfully written to a non-volatile memory array in the non-volatile memory, requesting additional data from the host and overwriting at least some the data in the data buffer with the additional data.

13. The method of claim 12, wherein requesting data associated with the pending host command comprises requesting the data from a host data buffer on the host.

14. The method of claim 12, wherein requesting data associated with the pending host command comprises requesting the data from a data buffer positioned in a memory in a location other than the data storage system or the host.

15. The method of claim 12, further comprising, in response to receiving an indication of a write failure relating to the first data, re-requesting the first data from the memory and, upon receipt of the re-requested first data at the data buffer, writing the first data from the data buffer to the non-volatile memory.

16. The method of claim 15, wherein receiving the indication of a write failure comprises receiving an indication of a voltage detection error at the data storage system.

17. The method of claim 15, wherein receiving the indication of a write failure comprises receiving an indication of an error correction failure.

18. The method of claim 12, further comprising delaying transmission of any write success message to the host until all data associated with the pending host command has been verified as successfully written to the non-volatile memory array in the non-volatile memory.

19. A non-transitory computer readable medium comprising processor executable instructions that, when executed by a controller of a data storage system, cause the controller to:

request, from a memory in communication with the data storage system, first data associated with a pending host command;

in response to receipt of the first data from the memory, write the first data to a data buffer in a volatile memory in the data storage system;

retrieve the first data from the data buffer and transfer the first data to data latches in a non-volatile memory of the storage system; and

retrieve additional data from the memory and overwrite at least a portion of the first data in the data buffer prior to executing a program command to program the first data from the data latches into a non-volatile memory array in the non-volatile memory.

20. The non-transitory computer readable medium of claim 19, wherein the processor executable instructions to request the first data from the memory comprise instructions to request the first data from a host data buffer on the host.

21. The non-transitory computer readable medium of claim 19, wherein the processor executable instructions to request the first data from the memory comprise instructions to request the first data from an external data buffer in a location other than on the host or the data storage system.