Patents by Inventor SATEESH DESIREDDI
SATEESH DESIREDDI 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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Patent number: 10558381Abstract: Apparatuses, systems, methods, and computer program products are disclosed for dynamic read table generation. One apparatus includes a set of non-volatile storage cells. A controller for a set of non-volatile storage cells is configured to, in response to unsuccessfully reading a storage cell of the set of non-volatile storage cells using a parameter, read the storage cell using one or more shifted values. A controller for a set of non-volatile storage cells is configured to, in response to successfully reading a storage cell using one or more shifted values, add the one or more shifted values to a storage device.Type: GrantFiled: December 16, 2016Date of Patent: February 11, 2020Assignee: SanDisk Technologies LLCInventors: Henry Chin, Sateesh Desireddi, Dana Lee, Ashwin D T, Harshul Gupta, Parth Amin, Jia Li
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Patent number: 10553301Abstract: Non-volatile memory and processes for reprogramming data posing a potential reliability concern are provided. A process is provided for distinguishing between cross-temperature effects and read disturb effects as part of determining whether to perform a maintenance operation such as reprogramming. A process is provided that compensates for cross-temperature effects while testing to determine whether to perform a maintenance operation. Applying temperature compensation attempts to remove cross-temperature effects so that testing accurately detects whether read disturb has occurred, without the effects of temperature. By reducing cross-temperature effects, maintenance operations can be more accurately scheduled for memory that has experienced read disturb, as opposed to cross-temperature effects.Type: GrantFiled: August 15, 2017Date of Patent: February 4, 2020Assignee: SanDisk Technologies LLCInventors: Narayan K, Sateesh Desireddi, Aneesh Puthoor, Dharmaraju Marenahally Krishna, Arun Thandapani, Divya Prasad, Thendral Murugaiyan, Piyush Dhotre
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Publication number: 20180350446Abstract: Non-volatile memory and processes for reprogramming data posing a potential reliability concern are provided. A process is provided for distinguishing between cross-temperature effects and read disturb effects as part of determining whether to perform a maintenance operation such as reprogramming. A process is provided that compensates for cross-temperature effects while testing to determine whether to perform a maintenance operation. Applying temperature compensation attempts to remove cross-temperature effects so that testing accurately detects whether read disturb has occurred, without the effects of temperature. By reducing cross-temperature effects, maintenance operations can be more accurately scheduled for memory that has experienced read disturb, as opposed to cross-temperature effects.Type: ApplicationFiled: August 15, 2017Publication date: December 6, 2018Applicant: SanDisk Technologies LLCInventors: Narayan K, Sateesh Desireddi, Aneesh Puthoor, Dharmaraju Marenahally Krishna, Arun Thandapani, Divya Prasad, Thendral Murugaiyan, Piyush Dhotre
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Publication number: 20180173447Abstract: Apparatuses, systems, methods, and computer program products are disclosed for dynamic read table generation. One apparatus includes a set of non-volatile storage cells. A controller for a set of non-volatile storage cells is configured to, in response to unsuccessfully reading a storage cell of the set of non-volatile storage cells using a parameter, read the storage cell using one or more shifted values. A controller for a set of non-volatile storage cells is configured to, in response to successfully reading a storage cell using one or more shifted values, add the one or more shifted values to a storage device.Type: ApplicationFiled: December 16, 2016Publication date: June 21, 2018Applicant: SanDisk Technologies LLCInventors: Henry Chin, Sateesh Desireddi, Dana Lee, Ashwin D T, Harshul Gupta, Parth Amin, Jia Li
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Patent number: 9703629Abstract: Devices and methods implemented therein in are disclosed for correcting errors in data. The method comprises determining that a first copy of data and a second copy of data include errors uncorrectable by an error correction code (ECC) engine. The ECC engine is modified based on determining that the first copy of data and the second copy of data include errors uncorrectable by the ECC engine and using the modified ECC engine, the first copy of data and the second copy of data are processed to correct the errors in the first and second copy of the data.Type: GrantFiled: March 13, 2015Date of Patent: July 11, 2017Assignee: SanDisk Technologies LLCInventors: Sateesh Desireddi, Nagi Reddy Chodem, Sachin Krishne Gowda
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Patent number: 9524799Abstract: Methods and apparatuses for performing receive and transmit path tuning of a toggle mode interface between a primary controller and a secondary controller is disclosed. A first component having a variable setting and connected with a data bus of the interface is iteratively adjusted. For each setting of the first component, test data written to the secondary controller and a delay unit having a variable delay setting and connected with a strobe line of the interface is adjusted. Delay settings are identified where the read data is equal to the written data. Settings for the first component and corresponding delay setting that produce the largest range of delay settings where the read data is equal to the written data is selected. The first component may correspond to a driver unit in the primary controller or an ODT unit in the secondary controller.Type: GrantFiled: June 15, 2015Date of Patent: December 20, 2016Assignee: SanDisk Technologies LLCInventors: Sateesh Desireddi, Srinivasa Rao Sabbineni, Shiv Harit Mathur
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Publication number: 20160189758Abstract: Methods and apparatuses for performing receive and transmit path tuning of a toggle mode interface between a primary controller and a secondary controller is disclosed. A first component having a variable setting and connected with a data bus of the interface is iteratively adjusted. For each setting of the first component, test data written to the secondary controller and a delay unit having a variable delay setting and connected with a strobe line of the interface is adjusted. Delay settings are identified where the read data is equal to the written data. Settings for the first component and corresponding delay setting that produce the largest range of delay settings where the read data is equal to the written data is selected. The first component may correspond to a driver unit in the primary controller or an ODT unit in the secondary controller.Type: ApplicationFiled: June 15, 2015Publication date: June 30, 2016Applicant: SanDisk Technologies Inc.Inventors: Sateesh Desireddi, Srinivasa Rao Sabbineni, Shiv Harit Mathur
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Publication number: 20160162357Abstract: Devices and methods implemented therein in are disclosed for correcting errors in data. The method comprises determining that a first copy of data and a second copy of data include errors uncorrectable by an error correction code (ECC) engine. The ECC engine is modified based on determining that the first copy of data and the second copy of data include errors uncorrectable by the ECC engine and using the modified ECC engine, the first copy of data and the second copy of data are processed to correct the errors in the first and second copy of the data.Type: ApplicationFiled: March 13, 2015Publication date: June 9, 2016Applicant: SanDisk Technologies Inc.Inventors: Sateesh Desireddi, Nagi Reddy Chodem, Sachin Krishne Gowda
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Patent number: 9349489Abstract: A data storage device includes non-volatile memory and a controller. The controller is configured to, at a first time, determine a first count of storage elements having threshold voltages within a voltage range that corresponds to a first reference voltage. The controller is further configured to, at a second time, determine a second count of storage elements having threshold voltages within the voltage range. The controller is further configured to calculate an updated first reference voltage at least partially based on the first reference voltage, the first count, and the second count.Type: GrantFiled: February 20, 2013Date of Patent: May 24, 2016Assignee: SANDISK TECHNOLOGIES INC.Inventors: Sateesh Desireddi, Jayaprakash Naradasi, Anand Venkitachalam, Manuel Antonio D'Abreu, Stephen Skala
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Patent number: 9318215Abstract: A data storage device includes non-volatile memory and a controller. The controller is configured to read first data from the non-volatile memory. The first data indicates a first count of storage elements of the group that have a first activation status when sensed with a first reference voltage at a first time. The controller is configured to read second data from the non-volatile memory. The second data indicates a second count of storage elements of the group that have the first activation status when sensed with the first reference voltage at a second time. The controller is configured to generate an updated first reference voltage at least partially based on a difference between the first count and the second count and based on one or more parameters corresponding to a distribution of threshold voltages of storage elements at the first time.Type: GrantFiled: April 11, 2013Date of Patent: April 19, 2016Assignee: SANDISK TECHNOLOGIES INC.Inventors: Sateesh Desireddi, Sachin Krishne Gowda, Jayaprakash Naradasi, Anand Venkitachalam, Manuel Antonio D'Abreu, Stephen Skala
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Patent number: 8996950Abstract: A method includes receiving a representation of a set of single error detection (SED) parity bits and a representation of data. The data includes an error correction coding (ECC) codeword including information bits and ECC parity bits. Each SED parity bit of the set of SED parity bits indicates a parity value for a corresponding portion of the data. The method includes, in response to determining that a particular portion of the representation of the data includes a single erasure bit, selectively modifying a bit value of the single erasure bit based on the representation of the SED parity bit that corresponds to the particular portion and generating an updated representation of the ECC codeword when the bit value of the single erasure bit corresponds to the ECC codeword and has been modified. The method may include initiating an ECC decode operation of the updated representation of the ECC codeword.Type: GrantFiled: March 22, 2012Date of Patent: March 31, 2015Assignee: Sandisk Technologies Inc.Inventor: Sateesh Desireddi
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Patent number: 8874992Abstract: In a data storage device that includes a non-volatile memory, a method includes determining that a current error correction code page count (CEC) is at least as large as a target error correction code page count (TEC). The CEC is a page count of error correction code (ECC) pages of data read from the memory during a time period from a previous time to a particular time using a set of reference voltages. In response to the CEC being at least as large as the TEC, the method includes updating a subset of the set of reference voltages conditioned upon a difference between a current mean error count (CMEC) and a previous mean error count being at least as large as a target mean delta error. The CMEC is based on a count of read errors associated with the ECC pages read during the time period.Type: GrantFiled: September 28, 2012Date of Patent: October 28, 2014Assignee: Sandisk Technologies Inc.Inventors: Sateesh Desireddi, Jayaprakash Naradasi, Anand Venkitachalam, Manuel Antonio D'Abreu, Stephen Skala
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Patent number: 8811076Abstract: A method includes, in a data storage device that includes a non-volatile memory, selecting an updated reference voltage as one of a reference voltage, a first alternate reference voltage and a second alternate reference voltage. The first alternate reference voltage and the second alternate reference voltage are calculated based on the reference voltage and based on a voltage increment. Selection of the updated reference voltage is based on a comparison of error counts, each error count associated with a unique one of the reference voltage, the first alternate reference voltage, and the second alternate reference voltage. The method includes resetting the reference voltage to the updated reference voltage, resetting the voltage increment to a reset voltage increment that is smaller than the voltage increment, and selecting an additional updated reference voltage based on the reset reference voltage and based on the reset voltage increment.Type: GrantFiled: August 30, 2012Date of Patent: August 19, 2014Assignee: SanDisk Technologies Inc.Inventors: Anand Venkitachalam, Sateesh Desireddi, Jayaprakash Naradasi, Manuel Antonio D'Abreu, Stephen Skala
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Publication number: 20140226398Abstract: A data storage device includes non-volatile memory and a controller. The controller is configured to read first data from the non-volatile memory. The first data indicates a first count of storage elements of the group that have a first activation status when sensed with a first reference voltage at a first time. The controller is configured to read second data from the non-volatile memory. The second data indicates a second count of storage elements of the group that have the first activation status when sensed with the first reference voltage at a second time. The controller is configured to generate an updated first reference voltage at least partially based on a difference between the first count and the second count and based on one or more parameters corresponding to a distribution of threshold voltages of storage elements at the first time.Type: ApplicationFiled: April 11, 2013Publication date: August 14, 2014Applicant: SANDISK TECHNOLOGIES INC.Inventors: SATEESH DESIREDDI, SACHIN KRISHNE GOWDA, JAYAPRAKASH NARADASI, ANAND VENKITACHALAM, MANUEL ANTONIO D'ABREU, STEPHEN SKALA
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Publication number: 20140201580Abstract: A data storage device includes non-volatile memory and a controller. The controller is configured to, at a first time, determine a first count of storage elements having threshold voltages within a voltage range that corresponds to a first reference voltage. The controller is further configured to, at a second time, determine a second count of storage elements having threshold voltages within the voltage range. The controller is further configured to calculate an updated first reference voltage at least partially based on the first reference voltage, the first count, and the second count.Type: ApplicationFiled: February 20, 2013Publication date: July 17, 2014Applicant: SANDISK TECHNOLOGIES INC.Inventors: SATEESH DESIREDDI, JAYAPRAKASH NARADASI, ANAND VENKITACHALAM, MANUEL ANTONIO D'ABREU, STEPHEN SKALA
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Publication number: 20140068382Abstract: In a data storage device that includes a non-volatile memory, a method includes determining that a current error correction code page count (CEC) is at least as large as a target error correction code page count (TEC). The CEC is a page count of error correction code (ECC) pages of data read from the memory during a time period from a previous time to a particular time using a set of reference voltages. In response to the CEC being at least as large as the TEC, the method includes updating a subset of the set of reference voltages conditioned upon a difference between a current mean error count (CMEC) and a previous mean error count being at least as large as a target mean delta error. The CMEC is based on a count of read errors associated with the ECC pages read during the time period.Type: ApplicationFiled: September 28, 2012Publication date: March 6, 2014Applicant: SANDISK TECHNOLOGIES INC.Inventors: SATEESH DESIREDDI, JAYAPRAKASH NARADASI, ANAND VENKITACHALAM, MANUEL ANTONIO D'ABREU, STEPHEN SKALA
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Publication number: 20140029336Abstract: A method includes, in a data storage device that includes a non-volatile memory, selecting an updated reference voltage as one of a reference voltage, a first alternate reference voltage and a second alternate reference voltage. The first alternate reference voltage and the second alternate reference voltage are calculated based on the reference voltage and based on a voltage increment. Selection of the updated reference voltage is based on a comparison of error counts, each error count associated with a unique one of the reference voltage, the first alternate reference voltage, and the second alternate reference voltage. The method includes resetting the reference voltage to the updated reference voltage, resetting the voltage increment to a reset voltage increment that is smaller than the voltage increment, and selecting an additional updated reference voltage based on the reset reference voltage and based on the reset voltage increment.Type: ApplicationFiled: August 30, 2012Publication date: January 30, 2014Applicant: SANDISK TECHNOLOGIES INC.Inventors: ANAND VENKITACHALAM, SATEESH DESIREDDI, JAYAPRAKASH NARADASI, MANUEL ANTONIO D'ABREU, STEPHEN SKALA
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Patent number: 8605502Abstract: A method includes, in a data storage device that includes a non-volatile memory, reading first data values from memory elements of the non-volatile memory using a set of reference voltages that includes a first reference voltage, and determining a first error count associated with the first reference voltage. The method includes reading second data values from the group of memory elements using a set of modified reference voltages that includes a modified first reference voltage, and determining a modified error count associated with the modified first reference voltage. The method includes updating the set of reference voltages to include the first reference voltage or the modified first reference voltage based on a comparison of the error count to the modified error count.Type: GrantFiled: June 14, 2012Date of Patent: December 10, 2013Assignee: Sandisk Technologies Inc.Inventors: Sateesh Desireddi, Jayaprakash Naradasi, Anand Venkitachalam
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Publication number: 20130314988Abstract: A method includes, in a data storage device that includes a non-volatile memory, reading first data values from memory elements of the non-volatile memory using a set of reference voltages that includes a first reference voltage, and determining a first error count associated with the first reference voltage. The method includes reading second data values from the group of memory elements using a set of modified reference voltages that includes a modified first reference voltage, and determining a modified error count associated with the modified first reference voltage. The method includes updating the set of reference voltages to include the first reference voltage or the modified first reference voltage based on a comparison of the error count to the modified error count.Type: ApplicationFiled: June 14, 2012Publication date: November 28, 2013Applicant: SANDISK TECHNOLOGIES INC.Inventors: SATEESH DESIREDDI, JAYAPRAKASH NARADASI, ANAND VENKITACHALAM
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Publication number: 20130227374Abstract: A method includes receiving a representation of a set of single error detection (SED) parity bits and a representation of data. The data includes an error correction coding (ECC) codeword including information bits and ECC parity bits. Each SED parity bit of the set of SED parity bits indicates a parity value for a corresponding portion of the data. The method includes, in response to determining that a particular portion of the representation of the data includes a single erasure bit, selectively modifying a bit value of the single erasure bit based on the representation of the SED parity bit that corresponds to the particular portion and generating an updated representation of the ECC codeword when the bit value of the single erasure bit corresponds to the ECC codeword and has been modified. The method may include initiating an ECC decode operation of the updated representation of the ECC codeword.Type: ApplicationFiled: March 22, 2012Publication date: August 29, 2013Applicant: SANDISK TECHNOLOGIES INC.Inventor: SATEESH DESIREDDI