Western Digital (fremont), Inc.

Western Digital Technologies, Inc.

Sandisk Technologies Inc.

Western Digital Corporation

Kroum Stanimirov Stoev

Francis H Liu

Yugang Wang

Dengtao Zhao

Haibo Li

Yongke Sun

Yingjian Chen

Eric J Champion

Suping Song

Christopher B Wolf

Tao Pan

Xiaozhong Dang

Zhigang Bai

Mohamad Towfik Krounbi

Matthew R Gibbons

Guirong Liang

Marcos Moises Lederman

Jui-Yao Yang

Peng Luo

Gulzar Ahmed Kathawala

Hai Jiang

Adam F Torabi

Liam Michael Parker

Xizeng Shi

Mei-Man L Syu

Dean Mitcham Jenkins

Mark David Thomas

Dale Charles Main

Yining Hu

Jun Liu

Yiming Huai

Sergey Anatolievich Gorobets

David John Seagle

James Han Wang

Lijie Guan

Steven Theodore Sprouse

Jing Zhang

Jack Frayer

Sharat Batra

Jack M Chue

William C Cain

Michael Alex

Biao Sun

Ming Zhao

Davide Guarisco

Lisha Wang

Satish Babu Vasudeva

Amritpal Singh Rana

Charles W Miller

Qing He

Jinghuan Chen

Bin Wu

Bogdan M Simion

Meiman Lin Syu

Adam Noah Jacobvitz

He Li

Kenneth Kung

Mathew Gibbons

Aparna C Vadde

Jinyoung Kim

Andrew Yu-Jen Wang

Aspects of a storage device including a memory and a controller are provided. The controller may determine to perform garbage collection on a superblock. During the garbage collection process, the controller will typically move the superblock into an erase pool for erasing the superblock. However, aspects of the disclosure are directed to a method of measuring a raw bit error rate (RBER) of the superblock prior to erasure. The measured RBER may be used to estimate a data retention time of the storage device and provide the customer with an early warning notification if a health metric of the storage devices reaches a threshold retention time.

Data retention (DR) warning system

The present disclosure, in various embodiments, describes technologies and techniques for use by a data storage controller for decoding codewords during an error correction read recovery process. In illustrative examples, an iterative procedure exploits artificial codewords generated using information obtained from a NAND or other non-volatile memory (NVM) in a previous sense operation. That is, procedures are described that use information obtained in one stage of read recovery to facilitate a subsequent stage to reduce the need to perform additional NAND senses. In one example, information obtained from a sense operation performed for an initial hard bit decode is used in subsequent soft bit decodes. Moreover, iterative decoding procedures are provided that progressively increase correction strength. The procedures may alternate between hard and soft reads while using syndrome weight to determine a failed bit code gradient for identifying the sensing voltage for a next hard sense.

Recovery combining hard decoding, soft decoding and artificial codeword generation

Embodiments of the present disclosure generally relate to SSD management of non-volatile memory blocks for writing multiple data streams. The SSD may include a non-volatile memory organized into a number of superblocks. Each superblock includes a number of streamblocks. In one embodiment, a method of operating the SSD includes receiving a data stream, identifying an open superblock, identifying an available streamblock from the open superblock, and assigning the data stream to the available streamblock from the open streamblock. In another embodiment, a method of operating the SSD includes receiving a first data stream and a second data stream, writing the first data stream to the first streamblock and writing the second data stream to the second streamblock, and calculating a combined XOR parity information for the first streamblock and the second streamblock.

Block management for data streams

A set of superblocks can be constructed by a memory controller employing good blocks and partially bad blocks in a plurality of memory access units. Each functional memory access unit among the plurality of memory access units contributes a single block that is a good block or a partially bad block to each superblock. The memory controller can further construct a set of super word line zones within each superblock in the set of superblocks. Each block within a superblock contributes a good word line zone to each super word line zone. Upon encounter of a program error at run time, the super word line zones within the superblock may be modified to continue running the program employing modified super word line zones for the superblock.

System and method for implementing super word line zones in a memory device

Systems and methods for managing data retention in a solid-state storage system utilizing data retention flag bytes are disclosed. A data storage device includes a non-volatile memory comprising a plurality of non-volatile memory devices and a controller configured to write data to a memory unit of the non-volatile memory array and write a data retention flag value indicating a number of bits of the written data programmed in a first of a plurality of logical states. The controller is further configured to read the data and determine a number of bits having the first of the plurality of logical states in the read data, and determine a difference between the number of bits of the written data programmed in the first logical state and the number of bits having the first logical state in the read data. The difference is used to determine data retention characteristics of the non-volatile memory.

Data retention flags in solid-state drives

A system and method is disclosed for managing data in a non-volatile memory. The system may include a non-volatile memory having multiple non-volatile memory sub-drives, including a staging sub-drive to receive all data from a host and a plurality of other sub-drives each associated with a respective data temperature range. A controller of the memory system is configured to route all incoming host data only to the staging sub-drive and during garbage collection each individual piece of valid data from a selected source block in a selected source sub-drive is routed to a respective one of the sub-drives. The method may include only routing host data to the staging sub-drive and only relocating valid data to sub-drives other than the staging sub-drive based on a determined temperature of valid data and a unique temperature range associated with sub-drives other than the staging sub-drive in the non-volatile memory system.

System and method of managing data in a non-volatile memory having a staging sub-drive

Systems and methods are disclosed for managing temperature in a data storage device. A data storage device includes non-volatile solid-state memory, a temperature sensor, a heating device, and a controller. The controller is configured to receive a temperature signal from the temperature sensor indicating a temperature of at least a portion of the data storage device, determine that the temperature is below a first predetermined threshold, activate the heating device to increase the temperature of the at least a portion of the data storage device, and write data associated with a write command to the non-volatile solid-state memory.

Temperature-based data refreshing

Systems and methods are disclosed for programming data in a non-volatile memory array are disclosed. A data storage device includes a non-volatile memory array including a plurality of non-volatile memory cells and a controller configured to receive a signal indicating a temperature of at least a portion of the data storage device. The controller determines a first offset program verify level associated with a first programming level based at least in part on the temperature and programs a first set of the memory cells of the non-volatile memory array using the first offset program verify level.

Temperature compensation management in solid-state memory

Temperature management in data storage devices

Systems and methods for data retention manager in a solid state storage system utilizing temperature measurement mechanisms are disclosed. Background data scanning can provide an efficient way to monitor data health and can be used to determine whether data refreshing is needed or to prevent data retention from degrading beyond error correction capabilities. In certain embodiments, data scanning may be performed as a background process regularly, for example, every month. However, effects of temperature on data retention may not be adequately accounted for using such methods. Certain embodiments disclosed herein provide a numerical integral method for taking account the system temperature by using the acceleration factor for data retention. Embodiments disclosed herein may provide for accurate handling of data retention in view of complex device temperature history.

Data retention monitoring using temperature history in solid state drives

A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of tracks, each track comprising a plurality of data sectors. A circular buffer is defined comprising a plurality of the tracks. During a garbage collection operation, write data is read from previously written valid data sectors corresponding to a tail of the circular buffer and stored in a non-volatile cache. During a flush operation, the write data is flushed from the non-volatile cache to the disk.

Disk drive using non-volatile cache when garbage collecting log structured writes

Growing community of inventors

Pleasanton, CA, United States of America

Kroum Stanimirov Stoev