Sandisk Technologies Inc.

Western Digital Technologies, Inc.

William Guthrie

Girish Desai

Shay Benisty

Yehuda Hahn

Yoav Weinberg

Gary Lin

Scheheresade Virani

Joseph Robert Meza

Vitali Linkovsky

Robert Jackson

Systems and methods for determining locality of an incoming command relative to previously identified write or read streams is disclosed. NVM Express (NVMe) implements a paired submission queue and completion queue mechanism, with host software on the host device placing commands into multiple submission queues. The memory device fetches the commands from the multiple submission queues, which results in the incoming commands being interspersed. In order to determine whether the incoming commands should be assigned to previously identified read or write streams, the locality of the incoming commands relative to the previously identified read or write streams is analyzed. One example of locality is proximity in address space. In response to determining locality, the incoming commands are assigned to the various streams.

System and method for locality detection to identify read or write streams in a memory device

Systems and methods for generating hint information associated with a host command are disclosed. In one implementation, a processor of a host system determines whether the host system has initiated a procedure that will send a command to a non-volatile memory system. The processor analyzes at least one of metadata or payload data associated with the command to determine whether the processor is able to generate hint information associated with the at least one of metadata or payload data. The processor generates hint information based on the analysis of the at least one of metadata or payload data, sends the hint information to the non-volatile memory system, and sends the command to the non-volatile memory system.

Systems and methods for generating hint information associated with a host command

Systems, methods and/or devices are used to enable enhancing data integrity to protect against returning old versions of data. In one aspect, the method includes (1) receiving a write request from a host that specifies write data for a set of logical block addresses in a logical address space of the host, (2) mapping the set of logical block addresses to a set of physical addresses corresponding to physical pages of the storage device, and (3) performing one or more operations for each logical block specified by the set of logical block addresses, including: (a) generating metadata for the logical block, the metadata including a version number for the logical block, (b) storing the metadata, including the version number, in a header of a physical page in which the logical block is stored, and (c) storing the version number in a version data structure.

Data integrity enhancement to protect against returning old versions of data

Systems, methods and/or devices are used to enhance data integrity to protect against returning old versions of data. In one aspect, a method includes (1) receiving a write request from a host that specifies write data for a set of logical block addresses, (2) mapping, using a mapping table, the set of logical block addresses to a set of physical addresses, where the mapping table includes a plurality of subsets, and (3) performing operations for each subset of the mapping table that includes at least one entry corresponding to a logical block specified by the set of logical block addresses, including: (a) generating metadata for the subset, the metadata including a version number for the subset, (b) calculating a Cyclic Redundancy Check (CRC) checksum for the subset, and (c) storing the version number for the subset and the CRC checksum for the subset in a version data structure.

Buffer memory reservation techniques for use with NAND flash memory include dynamically reserving regions of the buffer memory, responsive to a read/write request. Where the read/write request includes a plurality of data transfer requests, following completion of a data transfer request, the reserved buffer space may be recycled for use in a further data transfer request or for other purposes. During fulfillment of a read request, a buffer region is reserved from a larger buffer pool for a time period significantly smaller than the time required to execute a sense operation associated with the read request. The reserved buffer region may be reused for unrelated processes during execution of the sense operation.

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Santa Cruz, CA, United States of America

William Guthrie