Patents by Inventor Lanlan Gu

Lanlan Gu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11978490
    Abstract: This disclosure includes back pattern counter measures for solid state drives. Embodiments described herein include setting and applying read threshold offsets according to flags set based on an amount of data stored within a memory block (e.g., an “openness” of the block). The flag is implemented during read commands to account for shifts in voltage distribution of open blocks. A value of the flag may be chosen based on a number of word lines included in the block that store data. The read threshold offsets may further be based on at least one of the set flag or an age of a respective NAND cell.
    Type: Grant
    Filed: May 24, 2022
    Date of Patent: May 7, 2024
    Assignee: Western Digital Technologies, Inc.
    Inventors: Ming Jin, Yongke Sun, Lanlan Gu
  • Publication number: 20240070003
    Abstract: Aspects of a storage device including a memory and a controller are provided. The controller may measure an error rate of one or more blocks of the memory. In certain aspects, the controller may also estimate, based at least in part on the error rate, a time shift indicative of a duration of time for which the storage device was powered off. In some examples, the controller may also set a read level for multiple blocks of the memory, wherein the read level is determined based at least in part on the time shift.
    Type: Application
    Filed: August 30, 2022
    Publication date: February 29, 2024
    Inventors: Lisha WANG, James HIGGINS, Yongke SUN, Lanlan GU
  • Publication number: 20230410866
    Abstract: This disclosure includes back pattern counter measures for solid state drives. Embodiments described herein include setting and applying read threshold offsets according to flags set based on an amount of data stored within a memory block (e.g., an “openness” of the block). The flag is implemented during read commands to account for shifts in voltage distribution of open blocks. A value of the flag may be chosen based on a number of word lines included in the block that store data. The read threshold offsets may further be based on at least one of the set flag or an age of a respective NAND cell.
    Type: Application
    Filed: May 24, 2022
    Publication date: December 21, 2023
    Inventors: Ming Jin, Yongke Sun, Lanlan Gu
  • Patent number: 9910749
    Abstract: A non-volatile memory system includes a plurality of non-volatile data memory cells arranged into groups of data memory cells, a plurality of select devices connected to the groups of data memory cells, a selection line connected to the select devices, a plurality of data word lines connected to the data memory cells, and one or more control circuits connected to the selection line and the data word lines. The one or more control circuits are configured to determine whether the select devices are corrupted. If the select devices are corrupted, then the one or more control circuits repurpose one of the word lines (e.g., the first data word line closet to the select devices) to be another selection line, thus operating the memory cells connected to the repurposed word line as select devices.
    Type: Grant
    Filed: June 23, 2016
    Date of Patent: March 6, 2018
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Nian Niles Yang, Jiahui Yuan, Grishma Shah, Xinde Hu, Lanlan Gu, Bin Wu
  • Publication number: 20170371755
    Abstract: A non-volatile memory system includes a plurality of non-volatile data memory cells arranged into groups of data memory cells, a plurality of select devices connected to the groups of data memory cells, a selection line connected to the select devices, a plurality of data word lines connected to the data memory cells, and one or more control circuits connected to the selection line and the data word lines. The one or more control circuits are configured to determine whether the select devices are corrupted. If the select devices are corrupted, then the one or more control circuits repurpose one of the word lines (e.g., the first data word line closet to the select devices) to be another selection line, thus operating the memory cells connected to the repurposed word line as select devices.
    Type: Application
    Filed: June 23, 2016
    Publication date: December 28, 2017
    Applicant: SANDISK TECHNOLOGIES LLC
    Inventors: Nian Niles Yang, Jiahui Yuan, Grishma Shah, Xinde Hu, Lanlan Gu, Bin Wu
  • Patent number: 9620238
    Abstract: Non-volatile storage systems, and methods for programming non-volatile storage elements of non-volatile storage systems, are described herein. A method for programming a non-volatile storage element, wherein a loop number is incremented with each program-verify iteration includes performing a plurality of program-verify iterations for the non-volatile storage element. This includes inhibiting programming of the non-volatile storage element when the loop number is less than a loop number threshold corresponding to a target data state that the storage element is being programmed to. This also includes enabling programming of the non-volatile storage element when the the loop number is greater than or equal to the loop number threshold corresponding to the target data state that the storage element is being programmed to.
    Type: Grant
    Filed: September 22, 2014
    Date of Patent: April 11, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Anubhav Khandelwal, Dana Lee, Henry Chin, LanLan Gu
  • Publication number: 20150206593
    Abstract: Non-volatile storage systems, and methods for programming non-volatile storage elements of non-volatile storage systems, are described herein. A method for programming a non-volatile storage element includes performing a plurality of program-verify iterations for the non-volatile storage element. This includes inhibiting programming of the non-volatile storage element when a present program-verify iteration is less than a threshold corresponding to a target data state that the storage element is being programmed to. This also includes enabling programming of the non-volatile storage element when the present program-verify iteration is greater than or equal to the threshold corresponding to the target data state that the storage element is being programmed to.
    Type: Application
    Filed: September 22, 2014
    Publication date: July 23, 2015
    Inventors: Anubhav Khandelwal, Dana Lee, Henry Chin, LanLan Gu
  • Patent number: 9036416
    Abstract: Data, normally read using a page-by page read process, can be recovered from memory cells connected to a broken word line by performing a sequential read process. To determine whether a word line is broken, both a page-by page read process and a sequential read process are performed. The results of both read processes are compared. If the number of mismatches between the two read processes is greater than a threshold, it is concluded that there is a broken word line.
    Type: Grant
    Filed: November 13, 2012
    Date of Patent: May 19, 2015
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Nima Mokhlesi, Lanlan Gu, Ashish Pal Singh Ghai, Deepak Raghu
  • Patent number: 8804425
    Abstract: Methods and devices for operating non-volatile storage are disclosed. One or more programming conditions depend on the word line that is selected for programming. Applying a selected word line dependent program condition may reduce or eliminate program disturb. The duration of a programming pulse may depend on the word line that is selected for programming. This could be a physical characteristic of the word line or its location on a NAND string. As one example, a shorter pulse width may be used for the programming signal when programming edge word lines.
    Type: Grant
    Filed: March 26, 2012
    Date of Patent: August 12, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Wenzhou Chen, Guirong Liang, Lanlan Gu, Bo Lei
  • Publication number: 20130250688
    Abstract: Methods and devices for operating non-volatile storage are disclosed. One or more programming conditions depend on the word line that is selected for programming. Applying a selected word line dependent program condition may reduce or eliminate program disturb. The duration of a programming pulse may depend on the word line that is selected for programming. This could be a physical characteristic of the word line or its location on a NAND string. As one example, a shorter pulse width may be used for the programming signal when programming edge word lines.
    Type: Application
    Filed: March 26, 2012
    Publication date: September 26, 2013
    Inventors: Wenzhou Chen, Guirong Liang, Lanlan Gu, Bo Lei
  • Patent number: 8400854
    Abstract: The non-volatile storage system predicts which blocks (or other units of storage) will become bad based on performance data. User data in those blocks predicted to become bad can be re-programmed to other blocks, and the blocks predicted to become bad can be removed from further use.
    Type: Grant
    Filed: January 26, 2010
    Date of Patent: March 19, 2013
    Assignee: SanDisk Technologies Inc.
    Inventors: Gen Pei, Lanlan Gu, Nima Mokhlesi, Idan Alrod, Eran Sharon, Itshak Afriat
  • Publication number: 20110063918
    Abstract: The non-volatile storage system predicts which blocks (or other units of storage) will become bad based on performance data. User data in those blocks predicted to become bad can be re-programmed to other blocks, and the blocks predicted to become bad can be removed from further use.
    Type: Application
    Filed: January 26, 2010
    Publication date: March 17, 2011
    Inventors: Gen Pei, Lanlan Gu, Nima Mokhlesi, Idan Alrod, Eran Sharon, Itshak Afriat