Lsi Corporation

Seagate Technology Incorporated

Agere Systems Inc.

Avago Technologies General IP (singapore) Pte. Ltd.

Victor A Krachkovsky

Erich Franz Haratsch

Johnson Yen

Andrei Vityaev

Milos Ivkovic

Shaohua Yang

Nenad Miladinovic

Wu Chang

Clifton James Williamson

Razmik Karabed

Harley F Burger, Jr

Xiaotong Lin

Fan Zhang

Haitao Xia

Zongwang Li

Anatoli Aleksandrovich Bolotov

Mikhail I Grinchuk

Nils Graef

Hakan C Ozdemir

Zhiwei Wu

Zhijun Zhao

Ebad Ahmed

Clifton Williamson

Embodiments are related to systems and methods for data storage, and more particularly to systems and methods for storing and accessing data from a flash memory.

Systems and methods for efficient soft data based flash memory data recovery

A data encoder includes an encoding logic circuit configured to encode input data to apply run length limiting using state splitting of a code trellis, and a lookup table configured to apply a block-enumerable map on an un-split version of the code trellis, wherein entries in the lookup table are compressed.

State-split based encoder and decoder with table compression

Methods and apparatus are provided for soft data generation for memory devices using reference cells. At least one soft data value is generated in a memory device by writing a known data to one or more reference cells; reading one or more of the reference cells; obtaining a read statistic based on the read one or more reference cells; and obtaining the at least one soft data value based on the obtained read statistic. The read statistics can optionally be obtained for one or more desired locations of a memory array; or for a given pattern, PATT, in one or more aggressor cells. The read statistic can optionally comprise asymmetric statistics obtained for a plurality of possible values.

Methods and apparatus for soft data generation for memory devices based using reference cells

A storage system includes a storage medium operable to maintain a data set, a read/write head assembly operable to write the data set to the storage medium and to read the data set from the storage medium, a multi-level enumerative encoder operable to encode the data set before it is written to the storage medium as encoded data, wherein the enumerative encoder applies an enumeration using a plurality of level-dependent bases, and a decoder operable to decode the data set after it is read from the storage medium.

Multi-level enumerative encoder and decoder

Methods and apparatus are provided for storing data in a multi-level cell flash memory device with cross-page sectors, multi-page coding and per-page coding. A single sector can be stored across a plurality of pages in the flash memory device. Per-page control is provided of the number of sectors in each page, as well as the code and/or code rate used for encoding and decoding a given page, and the decoder or decoding algorithm used for decoding a given page. Multi-page and wordline level access schemes are also provided.

Methods and apparatus for storing data in a multi-level cell flash memory device with cross-page sectors, multi-page coding and per-page coding

Various embodiments of the present invention provide systems and methods for data processing. As an example, a data processing circuit is disclosed that includes a data detector circuit. The data detector circuit includes an anti-causal noise predictive filter circuit and a data detection circuit. In some cases, the anti-causal noise predictive filter circuit is operable to apply noise predictive filtering to a detector input to yield a filtered output, and the data detection circuit is operable to apply a data detection algorithm to the filtered output derived from the anti-causal noise predictive filter circuit.

Systems and methods for anti-causal noise predictive filtering in a data channel

A method of generating a hardware encoder includes generating a first directed graph characterizing a constraint set for a constrained system, identifying a scaling factor for an approximate eigenvector for the first directed graph, applying the scaling factor to the approximate eigenvector for the first directed graph to yield a scaled approximate eigenvector, partitioning arcs between each pair of states in the first directed graph, performing a state splitting operation on the first directed graph according to the partitioning of the arcs to yield a second directed graph, and generating the hardware encoder based on the second directed graph.

Encoder and decoder generation by state-splitting of directed graph

Methods and apparatus for soft data generation for memory devices using decoder performance feedback. At least one soft data value is generated in a memory device, by obtaining performance feedback from a decoder; obtaining an error statistic based on the performance feedback; and generating the at least one soft data value based on the obtained error statistic. The performance feedback comprises one or more of decoded bits, a number of erroneous bits based on data decoded by the decoder and a number of unsatisfied parity checks.

Methods and apparatus for soft data generation for memory devices using decoder performance feedback

Methods and apparatus are provided for soft data generation for memory devices. At least one soft data value is generated for a memory device, by obtaining at least one hard read value; and generating the soft data value associated with the at least one hard read value based on statistics for reading the hard read value. The hard read value may be one or more of data bits, voltage levels, current levels and resistance levels. The generated soft data value may be one or more of (i) a soft read value that is used to generate one or more log likelihood ratios, and (ii) one or more log likelihood ratios. The statistics comprise one or more of bit-based statistics and cell-based statistics. The statistics may also optionally comprise pattern-dependent disturbance of at least one aggressor cell on the target cell, as well as location-specific statistics. At least one soft data value can be generated for a memory device, by obtaining a soft read value; and generating the soft data value associated with the soft read value based on statistics for reading the soft read value, wherein the statistics comprise one or more of location-specific statistics and pattern-dependent statistics.

Methods and apparatus for soft data generation for memory devices

Methods and apparatus are provided for intercell interference mitigation using modulation coding. During programming of a flash memory, a modulation encoding is performed that selects one or more levels for programming the flash memory such that a reduced number of cells in the flash memory are programmed with a value that violates one or more predefined criteria. During a reading of a flash memory, a modulation decoding is performed that assigns one or more levels to cells in the flash memory such that a reduced number of cells in the flash memory are read with a value that violates one or more predefined criteria. The predefined criteria can be based, for example, on one or more of an amount of disturbance caused by the programmed cell; a voltage shift of a programmed cell: a voltage stored by a programmed cell; an amount of change in current through a programmed cell; and an amount of current through a programmed cell.

Methods and apparatus for intercell interference mitigation using modulation coding

Systems, methods, devices, circuits for data processing, and more particularly to penalty based multi-variant encoding of data.

Systems and methods for penalty based multi-variant encoding

Various embodiments of the present invention provide apparatuses, systems and methods for data detection in a detector with soft pruning. For example, a data detector is disclosed that includes a branch metric calculator operable to calculate branch metrics for transitions between states in a trellis for the data detector, and a branch metric offset circuit operable to apply branch metric offsets to the branch metrics to yield soft pruned branch metrics. The branch metric offsets comprise a range of probability values from zero percent to one hundred percent.

Detector with soft pruning

Methods and apparatus are provided for soft demapping and intercell interference mitigation in flash memories. In one variation, a target cell in a flash memory device capable of storing at least two data levels, s, per cell is read by obtaining a measured read value, r, for at least one target cell in the flash memory; obtaining a value, h, representing data stored for at least one aggressor cell in the flash memory; selecting one or more probability density functions based on a pattern of values stored in at least a portion of the flash memory, wherein the probability density functions comprises pattern-dependent disturbance of one or more aggressor cells on the at least one target cell in the flash memory; evaluating at least one selected probability density function based on the measured read value, r; and computing one or more log likelihood ratios based on a result of the evaluating step.

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Allentown, PA, United States of America

Victor A Krachkovsky