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).
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Publication number: 20240377963Abstract: A slow programming audit is performed on one or more memory blocks and/or associated word lines of one or more memory dies. The slow programming audit is used to determine whether identified or known weak word lines of one or more memory dies are causing performance issues. If it is determined that the weak word lines are causing data read, data write and/or data retention issues, the weak word lines of the one or more memory dies are marked for slow programming in subsequent programming operations.Type: ApplicationFiled: July 24, 2023Publication date: November 14, 2024Inventors: Scott Kayser, Yongke Sun, Lanlan Gu
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Patent number: 12086018Abstract: Aspects of the disclosure are directed to a storage device including a memory and a controller. In some examples, the controller is configured to measure an error rate of one or more blocks of the memory. In some examples, the controller is further configured to 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 is further configured to 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: GrantFiled: August 30, 2022Date of Patent: September 10, 2024Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Lisha Wang, James Higgins, Yongke Sun, Lanlan Gu
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Patent number: 11978490Abstract: 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: GrantFiled: May 24, 2022Date of Patent: May 7, 2024Assignee: Western Digital Technologies, Inc.Inventors: Ming Jin, Yongke Sun, Lanlan Gu
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Publication number: 20240070003Abstract: 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: ApplicationFiled: August 30, 2022Publication date: February 29, 2024Inventors: Lisha WANG, James HIGGINS, Yongke SUN, Lanlan GU
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Publication number: 20230410866Abstract: 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: ApplicationFiled: May 24, 2022Publication date: December 21, 2023Inventors: Ming Jin, Yongke Sun, Lanlan Gu
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Patent number: 9910749Abstract: 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: GrantFiled: June 23, 2016Date of Patent: March 6, 2018Assignee: SANDISK TECHNOLOGIES LLCInventors: Nian Niles Yang, Jiahui Yuan, Grishma Shah, Xinde Hu, Lanlan Gu, Bin Wu
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Publication number: 20170371755Abstract: 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: ApplicationFiled: June 23, 2016Publication date: December 28, 2017Applicant: SANDISK TECHNOLOGIES LLCInventors: Nian Niles Yang, Jiahui Yuan, Grishma Shah, Xinde Hu, Lanlan Gu, Bin Wu
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Methods and systems that selectively inhibit and enable programming of non-volatile storage elements
Patent number: 9620238Abstract: 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: GrantFiled: September 22, 2014Date of Patent: April 11, 2017Assignee: SanDisk Technologies LLCInventors: Anubhav Khandelwal, Dana Lee, Henry Chin, LanLan Gu -
Publication number: 20150206593Abstract: 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: ApplicationFiled: September 22, 2014Publication date: July 23, 2015Inventors: Anubhav Khandelwal, Dana Lee, Henry Chin, LanLan Gu
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Patent number: 9036416Abstract: 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: GrantFiled: November 13, 2012Date of Patent: May 19, 2015Assignee: SANDISK TECHNOLOGIES INC.Inventors: Nima Mokhlesi, Lanlan Gu, Ashish Pal Singh Ghai, Deepak Raghu
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Patent number: 8804425Abstract: 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: GrantFiled: March 26, 2012Date of Patent: August 12, 2014Assignee: SanDisk Technologies Inc.Inventors: Wenzhou Chen, Guirong Liang, Lanlan Gu, Bo Lei
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Publication number: 20130250688Abstract: 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: ApplicationFiled: March 26, 2012Publication date: September 26, 2013Inventors: Wenzhou Chen, Guirong Liang, Lanlan Gu, Bo Lei
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Patent number: 8400854Abstract: 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: GrantFiled: January 26, 2010Date of Patent: March 19, 2013Assignee: SanDisk Technologies Inc.Inventors: Gen Pei, Lanlan Gu, Nima Mokhlesi, Idan Alrod, Eran Sharon, Itshak Afriat
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Publication number: 20110063918Abstract: 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: ApplicationFiled: January 26, 2010Publication date: March 17, 2011Inventors: Gen Pei, Lanlan Gu, Nima Mokhlesi, Idan Alrod, Eran Sharon, Itshak Afriat