Patents by Inventor Yunxiang Wu

Yunxiang Wu 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: 20160085623
    Abstract: Systems and methods relating generally to solid state memory, and more particularly to systems and methods for recovering data from a solid state memory. An example data processing system includes a first circuit operable to yield a modified soft data set from a data set accessed from a solid state memory device, and a second circuit operable to apply a data decoding algorithm to the modified soft data to yield a decoded output.
    Type: Application
    Filed: December 1, 2015
    Publication date: March 24, 2016
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yunxiang Wu, Yu Cai, Erich F. Haratsch
  • Patent number: 9276609
    Abstract: Systems and method relating generally to solid state memory, and more particularly to systems and methods for generated data from a solid state memory. A data processing system includes a solid state memory, a data de-randomizer circuit operable to de-randomize a read data set accessed from the solid state memory device, a soft data generation circuit operable to receive multiple instances of one or more elements the read data set and access a scramble compensating extended look up table using the multiple instances of the element to receive corresponding soft data, and a data decoder circuit operable to apply a soft decoding algorithm to the soft data to yield a decoded output. Each instance of a respective element may be read using a different reference value.
    Type: Grant
    Filed: December 16, 2013
    Date of Patent: March 1, 2016
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Zhengang Chen, Yunxiang Wu, Erich F. Haratsch
  • Patent number: 9262268
    Abstract: An apparatus includes a memory and a controller. The memory includes a plurality of memory devices. Each memory device has a plurality of page types. The plurality of page types are classified based on error rate variations. The controller may be configured to write user data and error-correction data to the memory. The user data and the error-correction data are organized as a super-page. The super-page includes a plurality of sub-pages. The plurality of sub-pages are written across the plurality of memory devices such that the plurality of sub-pages are stored using more than one of the plurality of page types.
    Type: Grant
    Filed: February 5, 2014
    Date of Patent: February 16, 2016
    Assignee: Seagate Technology LLC
    Inventors: Yu Cai, Ning Chen, Yunxiang Wu, Erich F. Haratsch, Earl T. Cohen, Timothy L. Canepa
  • Patent number: 9239754
    Abstract: A Solid-State Disk (SSD) controller performs soft-decision decoding with a single read, thus improving performance, power, and/or reliability of a storage sub-system, such as an SSD. In a first aspect, the controller generates soft-decision metrics from channel parameters of a hard decode read, without additional reads and/or array accesses. In a second aspect, the controller performs soft decoding using the generated soft-decision metrics. In a third aspect, the controller generates soft-decision metrics and performs soft decoding with the generated soft-decision metrics when a hard decode read error occurs.
    Type: Grant
    Filed: August 4, 2012
    Date of Patent: January 19, 2016
    Assignee: Seagate Technology LLC
    Inventors: Yunxiang Wu, Zhengang Chen, Ning Chen
  • Patent number: 9236099
    Abstract: An apparatus having a circuit and a decoder is disclosed. The circuit is configured to (i) adjust an initial one of a plurality of reference voltages in a read channel of a memory by shifting the initial reference voltage an amount toward a center of a window and (ii) read a codeword from the memory a number of times. The window bounds a sweep of the reference voltages. Each retry of the reads uses a respective reference voltage from a pattern of the reference voltages. The pattern is symmetrically spaced about the initial reference voltage. The pattern fits in the window. The decoder is configured to generate read data by performing an iterative decoding procedure on the codeword based on the reads.
    Type: Grant
    Filed: December 20, 2013
    Date of Patent: January 12, 2016
    Assignee: Seagate Technology LLC
    Inventors: AbdelHakim S. Alhussien, Yunxiang Wu, Sundararajan Sankaranarayanan, Zhengang Chen, Erich F. Haratsch
  • Publication number: 20150370631
    Abstract: An apparatus having mapping and interface circuits. The mapping circuit (i) generates a coded item by mapping write unit bits using a modulation or recursion of past-seen bits, and (ii) calculates a particular state to program into a nonvolatile memory cell. The interface circuit programs the cell at the particular state. Two normal cell states are treated as at least four refined states. The particular state is one of the refined states. A mapping to the refined states mitigates programming write misplacement that shifts an analog voltage of the cell from the particular state to an erroneous state. The erroneous state corresponds to a readily observable illegal or atypical write sequence, and results in a modified soft decision from that calculated based on the normal states only. A voltage swing between the particular state and the erroneous state is less than between the normal states.
    Type: Application
    Filed: June 23, 2014
    Publication date: December 24, 2015
    Inventors: AbdelHakim S. Alhussien, Erich F. Haratsch, Earl T. Cohen, Yunxiang Wu
  • Patent number: 9218885
    Abstract: An apparatus comprising a memory and a controller. The memory is configured to process a plurality of read/write operations. The memory comprises a plurality of memory modules. Each memory module has a size less than a total size of the memory. The controller is configured to write user data using a plurality of threshold voltages. The data considered hot-read data is written using a first voltage threshold. The data not considered hot-read data is written using a second voltage threshold. The first voltage threshold reduces an impact on endurance of the memory.
    Type: Grant
    Filed: February 26, 2014
    Date of Patent: December 22, 2015
    Assignee: Seagate Technology LLC
    Inventors: Yu Cai, Yunxiang Wu, Erich F. Haratsch
  • Publication number: 20150363264
    Abstract: An apparatus comprising a memory and a controller. The memory may be configured to process a plurality of read/write operations. The memory may comprise a plurality of memory modules each having a size less than a total size of the memory. The controller may be configured to recover data stored in the memory determined to exceed a maximum number of errors after performing a first read operation using a first read reference voltage. The controller may perform a second read operation using a second read reference voltage. The controller may identify a victim cell having a threshold voltage in a region between the first read reference voltage and the second read reference voltage. The controller may perform a third read operation on aggressor cells of the victim cell. The controller may perform a fourth read operation using the first read reference voltage with bit-fixed values on the victim cell based on a type of interference from the aggressor cells.
    Type: Application
    Filed: June 16, 2014
    Publication date: December 17, 2015
    Inventors: Yu Cai, Yunxiang Wu, Erich F. Haratsch
  • Publication number: 20150364205
    Abstract: An apparatus comprising a memory and a controller. The memory may be configured to process a plurality of read/program operations. The memory may comprise a plurality of memory units each having a size less than a total size of the memory. The controller may be configured to perform a plurality of reads on a victim cell. The controller may be configured to store measured victim information from the plurality of reads on the victim cell. The controller may be configured to perform one or more reads on a plurality of aggressor cells. The controller may be configured to store measured aggressor information from the one or more reads on the plurality of aggressor cells. The controller may be configured to generate inter-cell interference parameters based on the measured victim information and the measured aggressor information. The controller may be configured to mitigate inter-cell interference based on the inter-cell interference parameters.
    Type: Application
    Filed: June 16, 2014
    Publication date: December 17, 2015
    Inventors: Zhengang Chen, Yunxiang Wu, Erich F. Haratsch
  • Patent number: 9213599
    Abstract: An apparatus includes a non-volatile memory and a controller. The controller may be configured to track one or more channel parameters of the non-volatile memory. The controller may be further configured to estimate an erase state voltage distribution of the non-volatile memory by selecting one or more parameters of the erase state distribution from a look-up table based upon at least one of the one or more channel parameters.
    Type: Grant
    Filed: September 30, 2013
    Date of Patent: December 15, 2015
    Assignee: Seagate Technology LLC
    Inventors: Yunxiang Wu, Zhengang Chen, Yu Cai, Erich F. Haratsch
  • Patent number: 9213600
    Abstract: An apparatus includes one or more error-correction decoders, a buffer, at least one direct memory access (DMA) engine, and at least one processor. The buffer may be configured to store data to be decoded by the one or more error-correction decoders. The at least one DMA engine may couple the buffer and the one or more error-correction decoders. The at least one processor may be enabled to send messages to the at least one DMA engine. The messages may be configured to deliver DMA control information and corresponding datapath control information. Data may be read from the buffer based upon the DMA control information and delivered to the one or more error-correction decoders along with the corresponding datapath control information. The one or more error-correction decoders may be enabled to decode the data read from the buffer according to the corresponding datapath control information.
    Type: Grant
    Filed: November 27, 2013
    Date of Patent: December 15, 2015
    Assignee: Seagate Technology LLC
    Inventors: Earl T. Cohen, Yunxiang Wu, Alexander Hubris, Christopher Brewer
  • Patent number: 9213602
    Abstract: An apparatus having mapping and interface circuits. The mapping circuit (i) generates a coded item by mapping write unit bits using a modulation or recursion of past-seen bits, and (ii) calculates a particular state to program into a nonvolatile memory cell. The interface circuit programs the cell at the particular state. Two normal cell states are treated as at least four refined states. The particular state is one of the refined states. A mapping to the refined states mitigates programming write misplacement that shifts an analog voltage of the cell from the particular state to an erroneous state. The erroneous state corresponds to a readily observable illegal or atypical write sequence, and results in a modified soft decision from that calculated based on the normal states only. A voltage swing between the particular state and the erroneous state is less than between the normal states.
    Type: Grant
    Filed: June 23, 2014
    Date of Patent: December 15, 2015
    Assignee: Seagate Technology LLC
    Inventors: AbdelHakim S. Alhussien, Erich F. Haratsch, Earl T. Cohen, Yunxiang Wu
  • Publication number: 20150355838
    Abstract: An adaptive channel tracking algorithm performed by a flash memory system obtains disparity metrics and derivative metrics and uses a combination of the disparity and derivative metrics to estimate an optimal read reference voltage. The estimation of the optimal read reference voltage does not rely on assumptions about the underlying cell voltage distributions and results in a good estimate of the read reference voltage even if the standard deviations of the cell voltage distributions are different. In addition, the algorithm is relatively simple and less computationally intensive to perform than the known tracking algorithms.
    Type: Application
    Filed: June 9, 2014
    Publication date: December 10, 2015
    Inventors: Zhengang Chen, Erich F. Haratsch, Sundararajan Sankaranarayanan, Yunxiang Wu
  • Patent number: 9201729
    Abstract: Systems and methods relating generally to solid state memory, and more particularly to systems and methods for recovering data from a solid state memory.
    Type: Grant
    Filed: November 5, 2013
    Date of Patent: December 1, 2015
    Assignee: SEAGATE TECHNOLOGY, LLC
    Inventors: Yunxiang Wu, Yu Cai, Erich F. Haratsch
  • Publication number: 20150339189
    Abstract: An apparatus comprising a memory and a controller. The memory may be configured to process a plurality of read/write operations. The memory comprises a plurality of memory units each having a size less than a total size of the memory. The controller may be configured to perform error correction code decoding on the memory units. The controller may be configured to generate a plurality of original log likelihood ratios each comprising a real value. The controller may be configured to convert each of the original log likelihood ratios to a converted log likelihood ratio comprising a fixed point value. The conversion comprises (a) scaling down a magnitude of each of the original log likelihood ratios, and (b) rounding each of the original log likelihood ratios having a scaled down magnitude to the fixed point value.
    Type: Application
    Filed: May 20, 2014
    Publication date: November 26, 2015
    Applicant: LSI Corporation
    Inventors: Yunxiang Wu, Yu Cai, Erich F. Haratsch
  • Publication number: 20150340100
    Abstract: An apparatus comprising a memory and a controller. The memory may be configured to process a plurality of read/program operations. The memory may comprise a plurality of memory units. The memory units may each have a size less than a total size of the memory. The memory units may include a plurality of cells. The controller may be configured to issue a plurality of program operations to write to one or more of the cells. The controller may be configured to implement a polling status command after each of the program operations to verify programming of each of the cells. A response to each of the polling status commands may be used to report a number of the cells that failed to be programmed.
    Type: Application
    Filed: May 22, 2014
    Publication date: November 26, 2015
    Inventors: Yu Cai, Yunxiang Wu, Erich F. Haratsch
  • Publication number: 20150331748
    Abstract: An apparatus comprising a memory and a controller. The memory may be configured to process a plurality of read/write operations. The memory comprises a plurality of memory units each having a size less than a total size of the memory. The controller may be configured to perform a first error correction code decoding on the memory units using a plurality of initial log likelihood ratio values. The controller may be configured to count a number of unsatisfied checks if the first error correction code decoding fails. The controller may be configured to generate a plurality of measured log likelihood ratio values if the number of unsatisfied checks is below a threshold. The plurality of measured log likelihood ratio values are (a) based on calculations using decoded bits of the first error correction code decoding, and (b) used to perform a second error correction code decoding on the memory units.
    Type: Application
    Filed: May 19, 2014
    Publication date: November 19, 2015
    Applicant: LSI Corporation
    Inventors: Earl T. Cohen, Yu Cai, Erich F. Haratsch, Yunxiang Wu
  • Patent number: 9189333
    Abstract: A flash memory controller having soft-decoding error correcting code (ECC) logic generates log likelihood ratio or similar ECC decoder soft input information from decision patterns obtained from reading data from the same portion of flash memory two or more times. Each decision pattern corresponds to a voltage region bordering one of the reference voltages. Each decision pattern represents a combination of flash memory bit value decisions for a cell voltage within the voltage region corresponding to the decision pattern when a corresponding combination of the reference voltages are used to read the cell. Numerical values are then computed in response to combinations of the flash memory bit value decisions represented by the decision patterns. The numerical values are provided to the soft-decoding ECC logic to serve as soft input information.
    Type: Grant
    Filed: October 28, 2013
    Date of Patent: November 17, 2015
    Assignee: Seagate Technology LLC
    Inventors: Yunxiang Wu, Zhengang Chen, Erich F. Haratsch
  • Patent number: 9176815
    Abstract: An apparatus for reading a flash memory includes a read controller operable to read the flash memory to yield read patterns, a likelihood generator operable to map the read patterns to likelihood values, a decoder operable to decode the likelihood values, a data state storage operable to retrieve the likelihood values for which decoding failed, and a selective dampening controller operable to select at least one dampening candidate from among the likelihood values for which decoding failed, to dampen the likelihood values of the at least one dampening candidate to yield dampened likelihood values, and to provide the dampened likelihood values to the decoder for decoding.
    Type: Grant
    Filed: November 29, 2013
    Date of Patent: November 3, 2015
    Assignee: Seagate Technology LLC
    Inventors: Zhengang Chen, Yunxiang Wu, AbdelHakim S. Alhussien, Erich F. Haratsch
  • Publication number: 20150309872
    Abstract: An apparatus comprising a memory and a controller. The memory is configured to process a plurality of read/write operations. The memory comprises a plurality of memory modules each having a size less than a total size of the memory. The controller is configured to salvage data stored in a failed page of the memory determined to exceed a maximum number of errors. The controller copies raw data stored in the failed page. The controller identifies locations of a first type of data cells that fail erase identification. The controller identifies locations of a second type of data cells that have program errors. The controller flips data values in the raw data at the locations of the first type of data cells and the locations of the second type of data cells. The controller is configured to perform error correcting code decoding on the raw data having flipped data values. The controller salvages data stored in the failed page.
    Type: Application
    Filed: May 9, 2014
    Publication date: October 29, 2015
    Applicant: LSI Corporation
    Inventors: Yu Cai, Yunxiang Wu, Erich F. Haratsch