Patents by Inventor Gautam Ashok Dusija

Gautam Ashok Dusija 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).

  • Publication number: 20210191796
    Abstract: A memory controller includes, in one embodiment, a memory interface and a dynamic stripe length manager circuit configured to receive a first weighted health factor associated with a first memory block of the memory, determine a first collective stripe length of the first memory block based on the first weighted health factor, set a first number of zones in the first memory block based on the first collective stripe length, monitor the memory to detect a trigger event that triggers a calculation of a second collective stripe length of the first memory block, the second collective stripe length being larger than the first collective stripe length, receive a second weighted health factor associated with the first memory block, determine the second collective stripe length based on the second weighted health factor, and set a second number of zones in the first memory block based on the second collective stripe length.
    Type: Application
    Filed: December 20, 2019
    Publication date: June 24, 2021
    Inventors: Abhijit Rao, Ramanathan Muthiah, Judah Gamliel Hahn, Gautam Ashok Dusija, Daniel Linnen
  • Patent number: 11042432
    Abstract: A memory controller includes, in one embodiment, a memory interface and a dynamic stripe length manager circuit configured to receive a first weighted health factor associated with a first memory block of the memory, determine a first collective stripe length of the first memory block based on the first weighted health factor, set a first number of zones in the first memory block based on the first collective stripe length, monitor the memory to detect a trigger event that triggers a calculation of a second collective stripe length of the first memory block, the second collective stripe length being larger than the first collective stripe length, receive a second weighted health factor associated with the first memory block, determine the second collective stripe length based on the second weighted health factor, and set a second number of zones in the first memory block based on the second collective stripe length.
    Type: Grant
    Filed: December 20, 2019
    Date of Patent: June 22, 2021
    Assignee: Western Digital Technologies, Inc.
    Inventors: Abhijit Rao, Ramanathan Muthiah, Judah Gamliel Hahn, Gautam Ashok Dusija, Daniel Linnen
  • Patent number: 10734079
    Abstract: The disclosure relates in some aspects to a read scrub design for a non-volatile memory that includes a block comprising N wordlines partitioned into a first sub-block comprising a first subset of the N wordlines and a second sub-block comprising a second subset of the N wordlines different than the first subset. In some aspects, the disclosure relates to detecting a trigger event associated with a read command performed on the first sub-block. A target sub-block test is then performed in response to a detection of the trigger event to determine whether to add the first sub-block to a read scrub queue. If the first sub-block is added to the read scrub queue, a sister sub-block test is then performed to determine whether to add the second sub-block to the read scrub queue.
    Type: Grant
    Filed: May 17, 2019
    Date of Patent: August 4, 2020
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Srinivasan Seetharaman, Sourabh Sankule, Piyush Girish Sagdeo, Gautam Ashok Dusija, Chris Nga Yee Yip
  • Patent number: 10459785
    Abstract: The present disclosure, in various embodiments, describes technologies and techniques for detecting errors in a non-volatile memory (NVM) device prior to performing re-training/recalibration. A processing device in a NVM controller detects a cyclic redundancy check (CRC) condition for detecting error in the NVM device, and a re-training condition that is based on the CRC condition. A CRC circuit generates CRC code when a CRC condition is detected, and the processing is configured to compare CRC code received from the NVM controller with the generated CRC code to detect error. A calibration circuit then re-trains the NVM device if the CRC circuit detects error and the re-training condition has been met.
    Type: Grant
    Filed: September 27, 2017
    Date of Patent: October 29, 2019
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Gautam Ashok Dusija, Venkatesh Prasa Ramachandra, Mrinal Kochar
  • Patent number: 10372342
    Abstract: Systems and methods for storing data in a multi-level cell (MLC) flash memory are disclosed. One such data storage system has a data path with cascaded data access performance, including multiple storage portions having different data access speeds. A cascaded data path enables flash memory data access that has a more graceful degradation instead of an abrupt decrease in performance during operation.
    Type: Grant
    Filed: October 2, 2017
    Date of Patent: August 6, 2019
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Gautam Ashok Dusija, Mrinal Kochar, Matthew Davidson
  • Patent number: 10373696
    Abstract: A method for writing data to a NAND flash memory is disclosed, having steps of writing a first set of data to a first memory block, writing a second set of data to a second memory block, writing a third set of data to a third memory block and writing a fourth set of data to a XNOR memory block.
    Type: Grant
    Filed: August 17, 2018
    Date of Patent: August 6, 2019
    Assignee: Western Digital Technologies, Inc.
    Inventors: Gautam Ashok Dusija, Aaron Lee, Mrinal Kochar, Deepak Raghu
  • Publication number: 20190102083
    Abstract: Systems and methods for storing data in a multi-level cell (MLC) flash memory are disclosed. One such data storage system has a data path with cascaded data access performance, including multiple storage portions having different data access speeds. A cascaded data path enables flash memory data access that has a more graceful degradation instead of an abrupt decrease in performance during operation.
    Type: Application
    Filed: October 2, 2017
    Publication date: April 4, 2019
    Inventors: Gautam Ashok Dusija, Mrinal Kochar, Matthew Davidson
  • Publication number: 20190095275
    Abstract: The present disclosure, in various embodiments, describes technologies and techniques for detecting errors in a non-volatile memory (NVM) device prior to performing re-training/recalibration. A processing device in a NVM controller detects a cyclic redundancy check (CRC) condition for detecting error in the NVM device, and a re-training condition that is based on the CRC condition. A CRC circuit generates CRC code when a CRC condition is detected, and the processing is configured to compare CRC code received from the NVM controller with the generated CRC code to detect error. A calibration circuit then re-trains the NVM device if the CRC circuit detects error and the re-training condition has been met.
    Type: Application
    Filed: September 27, 2017
    Publication date: March 28, 2019
    Inventors: Gautam Ashok Dusija, Venkatesh Prasa Ramachandra, Mrinal Kochar
  • Publication number: 20190057750
    Abstract: A method for writing data to a NAND flash memory is disclosed, having steps of writing a first set of data to a first memory block, writing a second set of data to a second memory block, writing a third set of data to a third memory block and writing a fourth set of data to a XNOR memory block.
    Type: Application
    Filed: August 17, 2018
    Publication date: February 21, 2019
    Inventors: Gautam Ashok DUSIJA, Aaron Lee, Mrinal Kochar, Deepak Raghu
  • Patent number: 9830108
    Abstract: A data storage device includes a memory (including a single level cell (SLC) memory portion and a multilevel cell (MLC) memory portion), a plurality of data latches, and routing circuitry coupled to the plurality of data latches. The routing circuitry is configured to cause write data, received from a controller, to be stored at a data latch of the plurality of data latches. The routing circuitry is further configured to cause the write data to be copied from the data latch to a particular portion of the memory based on receiving a program mode command after the write data is stored at the data latch, where the program mode command indicates the particular portion as one of the SLC memory portion or the MLC memory portion.
    Type: Grant
    Filed: October 12, 2015
    Date of Patent: November 28, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Jonathan Hsu, Gautam Ashok Dusija, Tienchien Kuo, Daniel Edward Tuers
  • Publication number: 20170102882
    Abstract: A data storage device includes a memory (including a single level cell (SLC) memory portion and a multilevel cell (MLC) memory portion), a plurality of data latches, and routing circuitry coupled to the plurality of data latches. The routing circuitry is configured to cause write data, received from a controller, to be stored at a data latch of the plurality of data latches. The routing circuitry is further configured to cause the write data to be copied from the data latch to a particular portion of the memory based on receiving a program mode command after the write data is stored at the data latch, where the program mode command indicates the particular portion as one of the SLC memory portion or the MLC memory portion.
    Type: Application
    Filed: October 12, 2015
    Publication date: April 13, 2017
    Inventors: JONATHAN HSU, GAUTAM ASHOK DUSIJA, TIENCHIEN KUO, DANIEL EDWARD TUERS
  • Patent number: 9384839
    Abstract: In a multi-level cell (MLC) nonvolatile memory array, data is assigned sequentially to the lower and upper page of a word line, then both lower and upper pages are programmed together before programming a subsequent word line. Word lines of multiple planes are programmed together using latches to hold data until all data is transferred. Tail-ends of data of write commands are stored separately.
    Type: Grant
    Filed: March 7, 2013
    Date of Patent: July 5, 2016
    Assignee: SanDisk Technologies LLC
    Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija
  • Patent number: 9230656
    Abstract: In a nonvolatile memory array in which a NAND string includes a back gate that has a charge storage element, the threshold voltage of the back gate is monitored, and if the threshold voltage deviates from a desired threshold voltage range, charge is added to, or removed from the charge storage element to return the threshold voltage to the desired threshold voltage range.
    Type: Grant
    Filed: June 26, 2013
    Date of Patent: January 5, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Yingda Dong, Jian Chen, Man Lung Mui, Alexander Kwok-Tung Mak, Seungpil Lee
  • Patent number: 9218242
    Abstract: Data that is stored in a higher error rate format in a nonvolatile memory is backed up in a lower error rate format. Data to be stored may be transferred once to on-chip data latches where it is maintained while it is programmed in both the high error rate format and the low error rate format without being resent to the nonvolatile memory.
    Type: Grant
    Filed: July 2, 2013
    Date of Patent: December 22, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Jian Chen, Mrinal Kochar, Abhijeet Manohar
  • Patent number: 9218890
    Abstract: When data from a portion of a three dimensional NAND memory array is determined to be uncorrectable by Error Correction Code (ECC), a determination is made as to whether data is uncorrectable by ECC throughout some unit that is larger than the portion. If modified read conditions provide ECC correctable data, the modified read conditions are recorded for subsequent reads of the larger unit.
    Type: Grant
    Filed: June 3, 2013
    Date of Patent: December 22, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Jian Chen, Yingda Dong, Man Lung Mui, Seungpil Lee, Alexander Kwok-Tung Mak
  • Patent number: 9183086
    Abstract: Portions of data stored in a three dimensional memory array are selected based on their locations for calculation of redundancy data. Locations are selected so that no two portions in a set of portions for a given calculation are likely to become uncorrectable at the same time. Selected portions may be separated by at least one word line and separated by at least one string in a block.
    Type: Grant
    Filed: June 3, 2013
    Date of Patent: November 10, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Jian Chen, Yingda Dong, Man Lung Mui, Seungpil Lee, Alexander Kwok-Tung Mak
  • Patent number: 9063671
    Abstract: Data that is stored in a higher error rate format in a nonvolatile memory is backed up in a lower error rate format. Data to be stored may be transferred once to on-chip data latches where it is maintained while it is programmed in both the high error rate format and the low error rate format without being resent to the nonvolatile memory. High error rate format may be MLC format and programming in the high error rate format may program both lower page and upper page data together in a full sequence programming scheme that is suitable for handling high data volume.
    Type: Grant
    Filed: July 2, 2013
    Date of Patent: June 23, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Jian Chen, Alexander Kwok-Tung Mak, Seungpil Lee, Mrinal Kochar, Pao-Ling Koh
  • Patent number: 9053011
    Abstract: Lower page data that may be endangered by programming upper page data in the same memory cells is protected during upper programming using protective upper page programming schemes. High overall programming speeds are maintained by selectively using protective upper programming schemes only where endangered data is committed and may not be recoverable from another location.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: June 9, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Jianmin Huang, Abhijeet Manohar, Chris Nga Yee Avila, Gautam Ashok Dusija
  • Patent number: 9047974
    Abstract: A method of determining whether a page of NAND flash memory cells is in an erased condition includes applying a first set of read conditions to identify a first number of cells having threshold voltages above a discrimination voltage under the first set of read conditions, if the first number of cells is less than a first predetermined number, applying a second set of read conditions that is different from the first set of read conditions to identify a second number of cells having threshold voltages above the discrimination voltage under the second set of read conditions, and if the second number of cells exceeds a second predetermined number, marking the page of flash memory cells as partially programmed.
    Type: Grant
    Filed: March 1, 2013
    Date of Patent: June 2, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Jianmin Huang, Zhenming Zhou, Gautam Ashok Dusija, Chris Nga Yee Avila, Dana Lee
  • Publication number: 20150067419
    Abstract: When a bad block is found in a nonvolatile memory array, the block is marked as a bad block so that it is not subsequently used. The block is also reconfigured as a bad block by increasing resistance of vertical NAND strings in the block by increasing threshold voltage of at least some transistors along vertical NAND strings, for example, select transistors or memory cell transistors.
    Type: Application
    Filed: September 3, 2013
    Publication date: March 5, 2015
    Applicant: SanDisk Technologies Inc.
    Inventors: Deepak Raghu, GAUTAM ASHOK DUSIJA, CHRIS NGA YEE AVILA, YINGDA DONG, MAN LUNG MUI