Abstract: A method for determining an optimal threshold of a nonvolatile memory device, the method including: reading a page from a nonvolatile memory device with a default threshold and attempting to hard decode the page using the default threshold; reading the page two more times with a predetermined offset voltage when the hard decoding fails and attempting to soft decode the page using the default threshold; approximating an empirical distribution of successfully decoded bits with a Gaussian distribution for each level; finding an intersection of the Gaussian distributions; and setting the intersection as a new reading threshold and reading the page again with the new reading threshold.

Abstract: A memory system including a nonvolatile memory (NVM) device and a controller is provided. The NVM device includes a main region and a spare region. The controller writes write data to a selected row of the main region, determines whether the written row is bad, and writes the write data to a spare address in the spare region and writes the spare address to the bad row, when the written row is determined to be bad.

Abstract: A memory system including a nonvolatile memory (NVM) device and a controller is provided. The NVM device includes a main region and a spare region. The controller writes write data to a selected row of the main region, determines whether the written row is bad, and writes the write data to a spare address in the spare region and writes the spare address to the bad row, when the written row is determined to be bad.

Abstract: A method for storing data within a memory device includes receiving data to be stored. The received data is encoded. The encoded data is stored within the memory device. Encoding the received data includes encoding the data into two or more sub-codewords. Each of the two or more sub-codewords includes a plurality of outer codewords. Two or more of the plurality of outer codewords are grouped to form a larger codeword that is larger than each of the plurality of outer codewords and the larger codeword is constructed to correct errors and/or erasures that are not correctable by the plurality of outer codewords, individually.

Abstract: A storage device includes a nonvolatile memory (NVM) device having a plurality of memory blocks and a control circuit configured to perform a read for copy-back operation in response to a receipt of a corresponding command. The control circuit performs the read for copy-back operation by reading page data from a source memory block of the plurality, generating a syndrome from the read page data, outputting the syndrome, receiving error location data in response to outputting the syndrome, correcting the read page data using the received error location data, and writing the corrected read page data to a target memory block among the plurality.

Abstract: A method for determining an optimal threshold of a nonvolatile memory device, the method including: reading a page from a nonvolatile memory device with a default threshold and attempting to hard decode the page using the default threshold; reading the page two more times with a predetermined offset voltage when the hard decoding fails and attempting to soft decode the page using the default threshold; approximating an empirical distribution of successfully decoded bits with a Gaussian distribution for each level; finding an intersection of the Gaussian distributions; and setting the intersection as a new reading threshold and reading the page again with the new reading threshold.

Abstract: A method for writing memory cells including: applying a program voltage to a target wordline; grounding bitlines of memory cells to be written to a first resistance state; setting a bitline voltage of unselected bitlines; and setting a wordline voltage of unselected wordlines; applying the program voltage to a target bitline; grounding wordlines of the memory cells to be written to a second resistance state; setting the wordline voltage of the unselected wordlines to a first value if a peak of a maximum voltage drop is greater than or equal to a second value; otherwise, setting the wordline voltage to zero; and setting the bitline voltage of the unselected bitlines to a third value if the peak of the maximum voltage drop is greater than or equal to the second value; otherwise, setting the bitline voltage to zero.

Abstract: A method of denoising intrinsic sneak currents in a PRAM memory array of M wordlines and N bitlines includes receiving, by the PRAM memory array, an input read address; and selecting from a table of wordline distances from a sense-amplifier versus estimated optimal currents for those wordline distances an estimated optimal reference current for a distance closest to the received input read address. The reference current determines whether a read current is ‘0’ or ‘1’ and minimizes a bit error rate due to effects of sneak paths and parasitic elements that distorts the read current.

Abstract: A method for writing memory cells including: applying a program voltage to a target wordline; grounding bitlines of memory cells to be written to a first resistance state; setting a bitline voltage of unselected bitlines; and setting a wordline voltage of unselected wordlines; applying the program voltage to a target bitline; grounding wordlines of the memory cells to be written to a second resistance state; setting the wordline voltage of the unselected wordlines to a first value if a peak of a maximum voltage drop is greater than or equal to a second value; otherwise, setting the wordline voltage to zero; and setting the bitline voltage of the unselected bitlines to a third value if the peak of the maximum voltage drop is greater than or equal to the second value; otherwise, setting the bitline voltage to zero.

Abstract: A storage device includes a nonvolatile memory (NVM) device having a plurality of memory blocks and a control circuit configured to perform a read for copy-back operation in response to a receipt of a corresponding command. The control circuit performs the read for copy-back operation by reading page data from a source memory block of the plurality, generating a syndrome from the read page data, outputting the syndrome, receiving error location data in response to outputting the syndrome, correcting the read page data using the received error location data, and writing the corrected read page data to a target memory block among the plurality.

Abstract: A method for performing a write operation in a random access memory (RAM) includes selecting a target block in a RAM with a greatest number of invalid pages, reading valid pages from target block, when a number of invalid pages is greater than a predetermined threshold, performing a bitline-wise block erase of the target block in said RAM, and copying-back valid data to the erased target block in a row-by-row set operation, wherein the erased target block is written with the valid data. Performing the bitline-wise block erase includes sequentially powering on each bitline with a predetermined reset voltage where all other bitlines and wordlines are grounded.

Abstract: A memory controller is configured to perform first error correcting code (ECC) encoding on a plurality of first frames of data, generate a plurality of delta syndrome units corresponding, respectively, to the plurality of first frames of data, generate a delta syndrome codeword by performing second ECC encoding on the plurality of delta syndrome units, the delta syndrome codeword including one or more redundancy data units, perform third ECC encoding on at least one second frame of data such that the encoded at least one second frame of data is a first vector of bits, and determine a second vector of bits such that, adding the second vector of bits to the first vector of bits forms a combined vector of bits which is an ECC codeword having a delta syndrome a value of which is pre-fixed based on at least one of the one or more redundancy data units.

Abstract: A solid-state drive (SSD) may include a volatile buffer such as DRAM, a non-volatile memory (NVM) such as NAND Flash connected to the volatile buffer, and a capacitor connected to both, where the capacitor may have an energy capacity insufficient to supply the buffer and NVM using a normal supply voltage in a normal mode, but sufficient to supply the buffer and NVM using at least one reduced supply voltage in a temporary mode; and a related method may include programming data to the NVM by temporarily reducing the supply voltage to the NVM, and writing data to the NVM using the reduced supply voltage.

Abstract: A method for determining an optimal threshold of a nonvolatile memory device, the method including: reading a page from a nonvolatile memory device with a default threshold and attempting to hard decode the page using the default threshold; reading the page two more times with a predetermined offset voltage when the hard decoding fails and attempting to soft decode the page using the default threshold; approximating an empirical distribution of successfully decoded bits with a Gaussian distribution for each level; finding an intersection of the Gaussian distributions; and setting the intersection as a new reading threshold and reading the page again with the new reading threshold.

Abstract: A decoding circuit includes a Bose-Chaudhuri-Hocquenghem (BCH) decoder. The BCH decoder includes a Syndrome stage for generating syndromes based on a BCH encoded word, a Berlekamp-Massey (BM) stage performing a Berlekamp-Massey algorithm on the syndromes to generate Error Location Polynomial (ELP) coefficients, a Chien stage that performs a Chien search on the ELP coefficients using a Fast Fourier Transform (FFT) to generate error bits and iteration information, and a Frame Fixer stage configured to reorder the error bits to be sequential based on the iteration information. The BCH decoder decodes the BCH encoded word using the reordered error bits.

Abstract: A method for performing a write operation in a random access memory (RAM) includes selecting a target block in a RAM with a greatest number of invalid pages, reading valid pages from target block, when a number of invalid pages is greater than a predetermined threshold, performing a bitline-wise block erase of the target block in said RAM, and copying-back valid data to the erased target block in a row-by-row set operation, wherein the erased target block is written with the valid data. Performing the bitline-wise block erase includes sequentially powering on each bitline with a predetermined reset voltage where all other bitlines and wordlines are grounded.

Abstract: A memory system includes a memory controller; and a memory device including a memory cell array, which includes a plurality of bit lines and a plurality of blocks. Each block includes a plurality of word lines, and each word line includes a plurality of phase-change random access memory (PRAM) cells connected, respectively, to the plurality of bit lines. The memory controller is configured to buffer write requests each including write data and is configured to perform a write operation that includes a reset phase and a subsequent set phase. The reset phase includes erasing the PRAM cells included in first word lines from among the plurality of word lines included in a selected block, from among the plurality of blocks, and the set phase includes, after the reset phase, writing the write data from the buffered write requests to the PRAM cells of the first word lines.

Abstract: A high-density storage system includes a memory device, and a controller including a range allocation and program order block configured to determine a range of a threshold voltage for each level of each memory cell of the memory device, based on initial data and an interference in the memory device, and determine an order in which groups of memory cells of the memory device are programmed, based on the interference. The controller further includes a statistical cell correction block configured to perform statistical cell correction on the range of the threshold voltage for each level of each memory cell, based on the order in which the groups of the memory cells are programmed and reference information of each level of each memory cell of the memory device that is received from the memory device.

Abstract: A method for writing data to a memory module, the method may include determining to write a representation of a data unit to a retired group of memory cells; searching for a selected retired group of memory cells that can store a representation of the data unit without being erased; and writing the representation of the data unit to the selected retired group of memory cells.

Abstract: A memory system includes a data channel, a controller configured to output a request across the data channel, and a memory device configured to store data and corresponding first parity, perform a decoding operation on the data to generate second parity in response to receipt of the request across the data channel, generate a difference from the first parity and the second parity, compress the difference, and enable the controller to access the data and the compressed difference to satisfy the request.