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).
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Publication number: 20210191796Abstract: 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: ApplicationFiled: December 20, 2019Publication date: June 24, 2021Inventors: Abhijit Rao, Ramanathan Muthiah, Judah Gamliel Hahn, Gautam Ashok Dusija, Daniel Linnen
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Patent number: 11042432Abstract: 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: GrantFiled: December 20, 2019Date of Patent: June 22, 2021Assignee: Western Digital Technologies, Inc.Inventors: Abhijit Rao, Ramanathan Muthiah, Judah Gamliel Hahn, Gautam Ashok Dusija, Daniel Linnen
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Patent number: 10734079Abstract: 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: GrantFiled: May 17, 2019Date of Patent: August 4, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Srinivasan Seetharaman, Sourabh Sankule, Piyush Girish Sagdeo, Gautam Ashok Dusija, Chris Nga Yee Yip
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Patent number: 10459785Abstract: 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: GrantFiled: September 27, 2017Date of Patent: October 29, 2019Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Gautam Ashok Dusija, Venkatesh Prasa Ramachandra, Mrinal Kochar
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Patent number: 10372342Abstract: 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: GrantFiled: October 2, 2017Date of Patent: August 6, 2019Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Gautam Ashok Dusija, Mrinal Kochar, Matthew Davidson
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Patent number: 10373696Abstract: 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: GrantFiled: August 17, 2018Date of Patent: August 6, 2019Assignee: Western Digital Technologies, Inc.Inventors: Gautam Ashok Dusija, Aaron Lee, Mrinal Kochar, Deepak Raghu
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Publication number: 20190102083Abstract: 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: ApplicationFiled: October 2, 2017Publication date: April 4, 2019Inventors: Gautam Ashok Dusija, Mrinal Kochar, Matthew Davidson
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Publication number: 20190095275Abstract: 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: ApplicationFiled: September 27, 2017Publication date: March 28, 2019Inventors: Gautam Ashok Dusija, Venkatesh Prasa Ramachandra, Mrinal Kochar
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Publication number: 20190057750Abstract: 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: ApplicationFiled: August 17, 2018Publication date: February 21, 2019Inventors: Gautam Ashok DUSIJA, Aaron Lee, Mrinal Kochar, Deepak Raghu
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Patent number: 9830108Abstract: 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: GrantFiled: October 12, 2015Date of Patent: November 28, 2017Assignee: SanDisk Technologies LLCInventors: Jonathan Hsu, Gautam Ashok Dusija, Tienchien Kuo, Daniel Edward Tuers
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Publication number: 20170102882Abstract: 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: ApplicationFiled: October 12, 2015Publication date: April 13, 2017Inventors: JONATHAN HSU, GAUTAM ASHOK DUSIJA, TIENCHIEN KUO, DANIEL EDWARD TUERS
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Patent number: 9384839Abstract: 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: GrantFiled: March 7, 2013Date of Patent: July 5, 2016Assignee: SanDisk Technologies LLCInventors: Chris Nga Yee Avila, Gautam Ashok Dusija
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Patent number: 9230656Abstract: 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: GrantFiled: June 26, 2013Date of Patent: January 5, 2016Assignee: SanDisk Technologies Inc.Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Yingda Dong, Jian Chen, Man Lung Mui, Alexander Kwok-Tung Mak, Seungpil Lee
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Patent number: 9218242Abstract: 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: GrantFiled: July 2, 2013Date of Patent: December 22, 2015Assignee: SanDisk Technologies Inc.Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Jian Chen, Mrinal Kochar, Abhijeet Manohar
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Patent number: 9218890Abstract: 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: GrantFiled: June 3, 2013Date of Patent: December 22, 2015Assignee: SanDisk Technologies Inc.Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Jian Chen, Yingda Dong, Man Lung Mui, Seungpil Lee, Alexander Kwok-Tung Mak
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Patent number: 9183086Abstract: 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: GrantFiled: June 3, 2013Date of Patent: November 10, 2015Assignee: SanDisk Technologies Inc.Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Jian Chen, Yingda Dong, Man Lung Mui, Seungpil Lee, Alexander Kwok-Tung Mak
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Patent number: 9063671Abstract: 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: GrantFiled: July 2, 2013Date of Patent: June 23, 2015Assignee: SanDisk Technologies Inc.Inventors: Chris Nga Yee Avila, Gautam Ashok Dusija, Jian Chen, Alexander Kwok-Tung Mak, Seungpil Lee, Mrinal Kochar, Pao-Ling Koh
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Patent number: 9053011Abstract: 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: GrantFiled: February 28, 2013Date of Patent: June 9, 2015Assignee: SanDisk Technologies Inc.Inventors: Jianmin Huang, Abhijeet Manohar, Chris Nga Yee Avila, Gautam Ashok Dusija
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Patent number: 9047974Abstract: 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: GrantFiled: March 1, 2013Date of Patent: June 2, 2015Assignee: SanDisk Technologies Inc.Inventors: Jianmin Huang, Zhenming Zhou, Gautam Ashok Dusija, Chris Nga Yee Avila, Dana Lee
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Publication number: 20150067419Abstract: 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: ApplicationFiled: September 3, 2013Publication date: March 5, 2015Applicant: SanDisk Technologies Inc.Inventors: Deepak Raghu, GAUTAM ASHOK DUSIJA, CHRIS NGA YEE AVILA, YINGDA DONG, MAN LUNG MUI