Abstract: A data storage device includes a memory having a three-dimensional (3D) memory configuration. The memory includes a structure that extends through multiple layers of the memory. A method includes storing information at the data storage device. The information identifies a location associated with a variation of the structure. The method further includes accessing the information.

Abstract: A data storage device includes a non-volatile memory that includes a three-dimensional (3D) memory. A method includes receiving first data and second data from a host device. A first error-correcting code (ECC) codeword associated with the first data is written to a first word line of the non-volatile memory, and a second ECC codeword associated with the second data is written to a second word line of the non-volatile memory. The first ECC codeword includes a first bit and a second bit, and the second ECC codeword includes a third bit and a fourth bit. The method further includes writing parity information to a parity storage portion of the non-volatile memory that is distinct from the first word line and from the second word line. The parity information includes a parity bit that is based on the first bit, the second bit, the third bit, and the fourth bit.

Abstract: A data storage device includes a controller that is configured to determine a first read voltage for a first page of a non-volatile memory (e.g., a lower page of a Multi-Level Cell flash memory device). The controller is also configured to determine a second read voltage for a second page (e.g., an upper page) of the non-volatile memory by applying an offset value to the first read voltage. The controller is also configured to store data identifying the first read voltage and the second read voltage.

Abstract: A data storage device includes a non-volatile memory and a controller. A method includes receiving first data and second data from a host device. A first error-correcting code (ECC) codeword associated with the first data is written to a first word line of the non-volatile memory, and a second ECC codeword associated with the second data is written to a second word line of the non-volatile memory. The first ECC codeword includes a first bit and a second bit, and the second ECC codeword includes a third bit and a fourth bit. The method further includes writing parity information to a parity storage portion of the non-volatile memory that is distinct from the first word line and from the second word line. The parity information includes a parity bit that is based on the first bit, the second bit, the third bit, and the fourth bit.

Abstract: Data to be stored in a nonvolatile memory array may be compressed in a manner that provides variable sized portions of compressed data, which is then padded to a predetermined uniform size and then stripped of padding. The encoded compressed data is sent to the memory array where it is stored in a uniform sized area that is exclusive to the encoded compressed data.

Abstract: A custom decoding algorithm is introduced, in connection with a corresponding decoding structure, to resolve many complexity and large memory requirements of known decoders. A system. A variable node forms a confidence vector of four components, one component for each state of a memory cell, and passes the current primary component (e.g., the largest) to one or more check nodes. The check nodes calculate a temporary component and corresponding index based on all components received from the variable nodes, which they pass back to the respective variable nodes. The variable node updates the confidence vector based on the temporary nodes received from respective check nodes, and determines the correct state for corresponding memory cell based on which component in the confidence vector is currently the primary component.

Abstract: A data storage device includes a non-volatile memory and a controller. A method includes programming information to the non-volatile memory. The information includes multiple codewords. The method further includes accessing a sample codeword of the multiple codewords from the non-volatile memory and determining an error rate associated with the sample codeword. The error rate is determined by an error correcting code (ECC) engine. The method further includes programming the information at the non-volatile memory in response to the error rate satisfying an error threshold.

Abstract: Disclosed is a system and method for reading a flash memory cell with an adjusted read level. A current read level is set to a new read level associated with increasing a first error rate to decrease a second error rate. The first error rate is associated with determining that the most significant bit of the flash memory cell is a binary 1 and the second error rate is associated with determining that the most significant bit is a binary 0. On reading the memory cell, a probability value is generated for the most significant bit, the probability being higher if the bit is equivalent to a binary 0 than if the bit is equivalent to a binary 1.

Abstract: Disclosed is an system and method for reading a flash memory cell with an adjusted read level. A current read level is adjusted to a new read level associated with increasing a first error rate to decrease a second error rate. The first error rate is associated with determining that the most significant bit of the flash memory cell is a binary 1 and the second error rate is associated with determining that the most significant bit is a binary 0. On reading the memory cell, a probability value is generated for the most significant bit, the probability being higher if the bit is equivalent to a binary 0 than if the bit is equivalent to a binary 1.

Abstract: The subject technology includes adjusting an error correcting code rate in a solid-state drive. A first plurality of memory operations are performed on a flash memory device of the solid-state drive using a first code rate. During operation of the drive, a controller monitors an operating condition associated with one or more memory units of the flash memory device for a trigger event. On the trigger event, the first code rate is adjusted in accordance with the operating condition to produce a second code rate, and a second plurality of memory operations is performed on the flash memory device using the second code rate.

Abstract: A method and system for storing data in a multi-level cell (MLC) flash memory device are described. The method includes receiving data for storage in the flash memory device, the flash memory device comprising an array of MLC flash memory cells, and encoding the received data into non-binary symbols according to a trellis-coded modulation scheme. The method further includes writing each of the non-binary symbols to a respective flash memory cell set, wherein each flash memory cell set comprises a plurality of MLC flash memory cells.

Abstract: Disclosed is an system and method for determining a probability that a memory cell was programmed to a certain input level. An output level is received from a memory cell and a probability is determined that the output level corresponds to each of a plurality of programming levels. Each probability is determined as a function of the output level, a mean value of a distribution corresponding to the programming level, and a variance from the mean value with the variance being determined by a relative position of the output level with respect to the mean value. A probability value is generated as a function of the plurality of determined probabilities and then provided for use at a demodulator.

Abstract: A method for calibrating read levels in a flash memory device is provided. The method includes receiving read information from flash memory in response to a read command, assigning soft information to the received read information, determining an error signal based on the assigned soft information, determining a read level offset based on the error signal, and adjusting a read level in the flash memory by the determined read level offset.

Abstract: A system and method for generating reliability information (aka “soft information”) from a flash memory device is disclosed. A plurality of memory cells are read by a data storage controller at a first read level to obtain a plurality of program values. On an error indicator being received in connection with reading the plurality of memory cells, the plurality of memory cells are read one or more times at one or more different read levels to categorize the plurality of memory cells into two or more cell program regions. A confidence value is then assigned to each memory cell based on a corresponding cell program region for the memory cell, the confidence value being representative of a likelihood that the memory cell is programmed to a corresponding program value read at the first read level.

Abstract: The subject technology provides a decoding solution that supports multiple choices of code rates. A decoder may be configured to receive a selected code rate from a plurality of code rates. On the selection of the code rate, the decoder may determine a circulant size based on the code rate, and, on receiving the codeword, update, during one or more parity-check operations, a number of confidence values proportional to the circulant size in each of a plurality of memory units, each number of confidence values corresponding to a portion of the codeword.

Abstract: The subject disclosure describes a method for reducing a sector error rate in a flash memory device, the method comprising, identifying a first program verify level having a first value, selecting an adjustment value for the first program verify level and programming the adjustment value to the first program verify level to replace the first value and to shift a first programming distribution associated with the first program verify level, wherein the shift in the first programming distribution is associated with a decrease in a sector error rate, wherein the shift in the first programming distribution is associated with an increase in a bit error rate. A flash storage device and computer-readable media are also provided.

Abstract: The subject disclosure describes a method for reducing a sector error rate in a flash memory device, the method comprising, identifying a first program verify level having a first value, selecting an adjustment value for the first program verify level and programming the adjustment value to the first program verify level to replace the first value and to shift a first programming distribution associated with the first program verify level, wherein the shift in the first programming distribution is associated with a decrease in a sector error rate, wherein the shift in the first programming distribution is associated with an increase in a bit error rate. A flash storage device and computer-readable media are also provided.

Abstract: The subject disclosure provides a method for generating a read-level error signal, comprising, correcting a plurality of bits read from a flash memory, determining a first error rate of a first error type corrected in the bits and determining a second error rate of a second error type corrected in the bits. In certain aspects, methods of the subject technology further provides steps for comparing the first error rate with the second error rate and generating a read-level error signal based on the comparison of the first error rate and the second error rate. A decoder and flash storage device are also provided.

Abstract: The subject technology provides a decoding solution that supports multiple choices of code rates. A decoder may be configured to receive a selected code rate from a plurality of code rates. On the selection of the code rate, the decoder may determine a circulant size based on the code rate, and, on receiving the codeword, update, during one or more parity-check operations, a number of confidence values proportional to the circulant size in each of a plurality of memory units, each number of confidence values corresponding to a portion of the codeword.

Abstract: A method and system for storing data in a multi-level cell (MLC) flash memory device are described. The method includes receiving data for storage in the flash memory device, the flash memory device comprising an array of MLC flash memory cells, and encoding the received data into non-binary symbols according to a trellis-coded modulation scheme. The method further includes writing each of the non-binary symbols to a respective flash memory cell set, wherein each flash memory cell set comprises a plurality of MLC flash memory cells.