Patents by Inventor Mrinal Kochar

Mrinal Kochar 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: 20210397505
    Abstract: The present disclosure generally relates to identifying read failures that enhanced post write/read (EPWR) would normally miss. After the last logical word line has been written, additional stress is added to each word line. More specifically, the gate bias channel pass read voltage for all unselected word lines is increased, the gate bias on dummy and selected gate word lines is increased, the gate bias on the selected word line is increased, and a pulse read occurs. The increasing and reading occurs for each word line. Thereafter, EPWR occurs. Due to the increasing and reading for every word line, additional read failures are discovered than would otherwise be discovered with EPWR alone.
    Type: Application
    Filed: June 18, 2020
    Publication date: December 23, 2021
    Inventors: Piyush DHOTRE, Sahil SHARMA, Mrinal KOCHAR, Shantanu GUPTA
  • Publication number: 20210149800
    Abstract: A system and method for a power-cycle based read scrub of a memory device is provided. A controller stores an access counter which indicates a number of times a logical block address (LBA) has been accessed. When the LBA is accessed, the LBA counter is incremented. If the LBA counter indicates a count higher than a predetermined count, data stored in the LBA is duplicated and the duplicate data is stored as backup data. Subsequent access of the LBA will show that the LBA count is higher than the predetermined count, so the backup data will be accessed rather than the original LBA, thus preventing read-induced failure of the data which may be caused by further repeated access of the same LBA.
    Type: Application
    Filed: November 20, 2019
    Publication date: May 20, 2021
    Applicant: Western Digital Technologies, Inc.
    Inventors: Niles Yang, Lior Avital, Mrinal Kochar, Daniel Linnen, Rohit Sehgal
  • 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: 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
  • 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
  • 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
  • Publication number: 20180374547
    Abstract: The temperature of the various devices on a printed circuit board (PCB) can change over time as the PCB is used. Additionally, the various devices on the PCB can have different temperatures at the same time. For example, the closer a device is to a heat source, the greater the temperature. Similarly, the further away from the heat source, the lower the temperature. Thus, otherwise identical devices on a PCB can have different temperatures at the same time, and additionally, the temperatures can change over time. By periodically measuring the temperature of the devices, the thermal disparity for the devices can be efficiently and intelligently managed.
    Type: Application
    Filed: June 22, 2017
    Publication date: December 27, 2018
    Inventors: Nian Niles YANG, Philip David REUSSWIG, Mrinal KOCHAR, Varuna KAMILA
  • Patent number: 10014056
    Abstract: Apparatuses, systems, methods, and computer program products are disclosed for changing storage parameters. An integrated circuit (IC) memory element receives a command to change a value of a parameter associated with the IC memory element. A parameter includes a setting for one or more storage operations of an IC memory element. An IC memory element receives one or more data sets with a command. A data set includes an identifier associated with a parameter to be changed and a new value for the parameter. Each of one or more data sets is received at a same data rate as a command. An IC memory element writes, for each of one or more data sets, a new value for a parameter to a storage location associated with the parameter.
    Type: Grant
    Filed: May 18, 2017
    Date of Patent: July 3, 2018
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Aaron Lee, Yi-Chieh Chen, Anne Koh, Gulzar Kathawala, Mrinal Kochar
  • Patent number: 9983920
    Abstract: A system and method for operating a memory system includes receiving a first user data, writing the first user data to a first buffer, writing the first user data from the first buffer to a first selected memory location, writing the first user data from the first buffer into a second buffer when the first user data was successfully written to the first selected memory location. Data is retrieved from the first selected memory location and written into the first buffer. Data in the first buffer can be matched to the user data in the second buffer to confirm a successful storage of the first user data in the memory system. A previously stored user data can be retrieved from a third selected memory location and written into a third buffer when the previously stored user data was stored in the memory system before the first user data.
    Type: Grant
    Filed: May 9, 2016
    Date of Patent: May 29, 2018
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Abhijeet Bhalerao, Mrinal Kochar, Aaron Lee
  • Patent number: 9977628
    Abstract: A storage module and method for configuring the storage module with memory operation parameters are provided. In one embodiment, a storage module is provided comprising a memory and a controller. The controller is configured to receive a selection of one of a plurality of sets of memory operation parameters stored in the storage module and perform at least one of a read operation and a write operation on the memory in accordance with the selected set of memory operation parameters.
    Type: Grant
    Filed: April 16, 2014
    Date of Patent: May 22, 2018
    Assignee: SanDisk Technologies LLC
    Inventors: Mrinal Kochar, Shmoolik Yosub, Yong Peng, Yong Huang
  • Patent number: 9858009
    Abstract: Data that is initially stored in Single Level Cell (SLC) blocks is subsequently copied (folded) to a Multi Level Cell (MLC) block where the data is stored in MLC format, the data copied in a minimum unit of a fold-set, the MLC block including a plurality of separately-selectable sets of NAND strings, data of an individual fold-set copied exclusively to two or more word lines of an individual separately-selectable set of NAND strings in the MLC block.
    Type: Grant
    Filed: October 26, 2015
    Date of Patent: January 2, 2018
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Abhijeet Bhalerao, Mrinal Kochar, Dennis S. Ea, Mikhail Palityka, Aaron Lee, Yew Yin Ng, Ivan Baran
  • Patent number: 9804922
    Abstract: Systems and methods for partial bad block reuse may be provided. Data may be copied from a block of a first memory to a block of a second memory. A post write read error may be detected in a first portion the data copied to the block of the second memory without detection of a post write read error in a second portion of the data copied to the block of the second memory. The block of the second memory may be determined to be a partial bad block usable for storage in response to detection of the post write read error in the first portion of the data but not in the second portion of the data.
    Type: Grant
    Filed: July 21, 2014
    Date of Patent: October 31, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Mrinal Kochar, Abhijeet Bhalerao, Derek McAuley, Piyush Sagdeo
  • Patent number: 9792175
    Abstract: When the number of bad columns in a memory or plane is less than a threshold number then a first Error Correction Code (ECC) scheme encodes user data in first pages of a first size. If the number of bad columns is greater than the threshold number then a second ECC scheme encodes the user data in second pages of a second size that is smaller than the first size.
    Type: Grant
    Filed: October 21, 2015
    Date of Patent: October 17, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Sahil Sharma, Abhijeet Manohar, Mrinal Kochar, Yong Huang, Derek McAuley, Mikhail Palityka, Ivan Baran, Aaron Lee
  • Patent number: 9760303
    Abstract: Partially-bad blocks are identified in a 3-D block-erasable nonvolatile memory, each partially-bad block having one or more inoperable separately-selectable sets of NAND strings and one or more operable separately-selectable sets of NAND strings. Operable sets of NAND strings within two or more partially-bad blocks are identified and are mapped to form one or more virtual blocks that are individually assigned virtual block addresses. The virtual block address are maintained in a list and used to access the virtual blocks.
    Type: Grant
    Filed: September 29, 2015
    Date of Patent: September 12, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Dennis S. Ea, Ivan Baran, Aaron Lee, Mrinal Kochar, Mikhail Palityka, Yew Yin Ng, Abhijeet Bhalerao
  • Patent number: 9728262
    Abstract: Non-volatile memory systems with multi-write direction memory units are disclosed. In one implementation an apparatus comprises a non-volatile memory and a controller in communication with the non-volatile memory. The controller is configured to select an empty memory block of the non-volatile memory for the storage of data; examine an identifier associated with the memory block to determine a write direction for the storage of data; and write data to the memory block beginning with an initial word line of the memory block or a last word line of the memory block dependent on the write direction. The controller is further configured to erase the memory unit and, in response to erasing the memory unit, modify the identifier to change the write direction for a subsequent write of data to the memory block.
    Type: Grant
    Filed: October 30, 2015
    Date of Patent: August 8, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Ivan Baran, Aaron Lee, Mrinal Kochar, Mikhail Palityka, Dennis Ea, Yew Yin Ng, Abhijeet Bhalerao
  • Publication number: 20170123994
    Abstract: Technology is described herein for reclaiming a memory device that has a defective plane. A solution allows a memory device with a defective plane to operate as a single plane device. The memory device with the defective plane may be used without any changes to the memory controller. Thus, the memory controller can send single plane commands to the memory device with the defective plane by using single plane addressing. The memory device may have logic that properly translates the single plane command so that it is compliant with the memory mapping of the multi-plane memory device with the defective plane. Thus, the command will access the correct block in the correct plane.
    Type: Application
    Filed: October 28, 2015
    Publication date: May 4, 2017
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Tosha Pandya, Mrinal Kochar, Aaron Lee, Tien-Chien Kuo
  • Publication number: 20170125104
    Abstract: Non-volatile memory systems with multi-write direction memory units are disclosed. In one implementation an apparatus comprises a non-volatile memory and a controller in communication with the non-volatile memory. The controller is configured to select an empty memory block of the non-volatile memory for the storage of data; examine an identifier associated with the memory block to determine a write direction for the storage of data; and write data to the memory block beginning with an initial word line of the memory block or a last word line of the memory block dependent on the write direction. The controller is further configured to erase the memory unit and, in response to erasing the memory unit, modify the identifier to change the write direction for a subsequent write of data to the memory block.
    Type: Application
    Filed: October 30, 2015
    Publication date: May 4, 2017
    Applicant: SanDisk Technologies Inc.
    Inventors: Ivan Baran, Aaron Lee, Mrinal Kochar, Mikhail Palityka, Dennis Ea, Yew Yin Ng, Abhijeet Bhalerao
  • Publication number: 20170116076
    Abstract: When the number of bad columns in a memory or plane is less than a threshold number then a first Error Correction Code (ECC) scheme encodes user data in first pages of a first size. If the number of bad columns is greater than the threshold number then a second ECC scheme encodes the user data in second pages of a second size that is smaller than the first size.
    Type: Application
    Filed: October 21, 2015
    Publication date: April 27, 2017
    Inventors: Sahil Sharma, Abhijeet Manohar, Mrinal Kochar, Yong Huang, Derek McAuley, Mikhail Palityka, Ivan Baran, Aaron Lee