Abstract: Systems and methods are provided for decoding data. A first decoder attempts to decode the data based on a hard decision input for a symbol. When the attempt to decode the data based on the hard decision input fails, a request is transmitted reliability information for the symbol. Receiving circuitry receives the reliability information for the symbol, and a second decoder decodes the data based on the reliability information.

Abstract: Systems and methods are provided for decoding data. A decoder receives a plurality of variable node values for a plurality of variable nodes and processed reliability data for at least a subset of the plurality of variable nodes. Circuitry updates the variable node values based on the variable node values and the processed reliability data. The processed reliability data represents a version of the reliability data for at least the subset of the plurality of variable nodes.

Abstract: Systems and methods are provided for decoding data. A variable node value for a variable node is received at a first time, and reliability data for the variable node is received at a second time. The variable node is decoded using a first decoding scheme after the first time and before the second time, and the variable node is decoded using a second decoding scheme different from the first decoding scheme after the second time.

Abstract: The present disclosure includes systems and techniques relating to non-volatile memory. A described system, for example, includes a non-volatile memory structure having a plurality of multi-level memory cells, a processing device, and a controller. The controller is configured to map a first portion of a first set of consecutive bits of a data segment to a first page associated with the plurality of multi-level memory cells, and map a second portion of the first set of consecutive bits of the data segment to a second page associated with the plurality of multi-level memory cells. The first page is associated with bits of a first significance, and the second page is associated with bits of a second significance.

Abstract: Systems and methods are provided for decoding data. A decoder receives a variable node value and reliability data for a variable node, and check node values for check nodes associated with the variable node. Circuitry generates an updated variable node value, based on the received reliability data and the received check node values. The circuitry also generates, for at least one check node, an updated check node value based on the updated variable node value.

Abstract: Systems and methods are provided to generate soft information related to the threshold voltage of a memory cell. A range of threshold voltages for the memory cell is divided into subregions of threshold voltage values herein referred to as bins. An output of the memory cell in response to an applied reference signal is measured. The applied reference signal includes a voltage value and position information. A single bin is identified based on the position information of the reference signal. The identified bin is split into more than one bin based on the output of the memory cell and the voltage value of the reference signal. The newly split bins and all the other bins that were not split are assigned new bin indices.

Abstract: Systems and methods are provided for decoding data using hard decisions and soft information. In particular, the systems and methods described herein are directed to decoders having variable nodes and check nodes, each with multiple states. The systems and methods include receiving, at a decoder during a first iteration, values for each of a plurality of variable nodes, and determining, during a second iteration, one or more indications for each of a plurality of check nodes based on the one or more values of the variable nodes received during the first iteration. The methods further include updating, at the decoder during the second iteration, the values for each of the variable nodes based on the values of the respective variable node received during the first iteration, and the indications for each of the plurality connected check nodes during the first iteration.

Abstract: Systems and methods are provided to generate soft information related to the threshold voltage of a memory cell. A range of threshold voltages for the memory cell is divided into subregions of threshold voltage values herein referred to as bins. An output of the memory cell in response to an applied reference signal is measured. The applied reference signal includes a voltage value and position information. A single bin is identified based on the position information of the reference signal. The identified bin is split into more than one bin based on the output of the memory cell and the voltage value of the reference signal. The newly split bins and all the other bins that were not split are assigned new bin indices.

Abstract: Systems and methods are provided for decoding data. A decoder retrieves data related to a symbol and identifies a plurality of candidate values for the symbol. The decoder determines a distance between each of the plurality of candidate values and a reference value associated with the symbol to obtain a plurality of distances, and the decoder determines whether to update a value of the symbol based at least in part on the plurality of distances.

Abstract: Systems and methods are provided for decoding data using hard decisions and erasures. Circuitry receives data from each of a plurality of variable nodes which correspond to bits of data being decoded. Each variable node stores one of at least three values. The circuitry determines processes the values received from the plurality of variable nodes according to a set of processing rules. The processing rules are used to determine a condition related to the values stored by the plurality of variable nodes. The circuitry stores an indication of the stored condition at a check node.

Abstract: A system including a read module to perform a first read operation to determine a state of a memory cell, and in response to a first failure to decode data read from the memory cell, perform second and third read operations to determine the state of the memory cell. The memory cell has first and second threshold voltages when programmed to first and second states, respectively. A shift detection module detects, in response to a second failure to decode data read from the memory cell in the second and third read operations, a shift in a distribution of at least one of the first and second threshold voltages. A binning module divides the distribution into a plurality of bins. A log-likelihood ratio (LLR) module generates LLRs for the plurality of bins based on a variance of the distribution and adjusts the LLRs based on an amount of the shift.

Abstract: An apparatus including a memory array and control circuitry. The control circuitry is configured to, based at least on a plurality of read comparison results, determine a number of memory cells of the memory array that have threshold voltages that fall into each of a plurality of voltage ranges. The control circuitry is further configured to, based at least on the number of memory cells that have threshold voltages in each of the plurality of voltage ranges, estimate an offset amount that a center voltage between two threshold voltage distributions differs from a center reference voltage. The control circuitry is further configured to read one or more of the plurality of memory cells based at least in part on the estimated offset amount.

Abstract: A system including a reference voltage module to select a first reference voltage between a first threshold voltage corresponding to a first state of a memory cell and a second threshold voltage corresponding to a second state of the memory cell, a second reference voltage less than the first reference voltage, and a third reference voltage greater than the first reference voltage. The system includes a read module to perform a first read operation to determine a state of the memory cell based on the first reference voltage, and in response to a first failure to decode data read from the memory cell in the first read operation, perform a second read operation to determine the state based on the second reference voltage and a third read operation to determine the state based on the third reference voltage.

Abstract: In this invention, a new class of finite precision multilevel decoders for low-density parity-check (LDPC) codes is presented. These decoders are much lower in complexity compared to the standard belief propagation (BP) decoder. Messages utilized by these decoders are quantized to certain levels based on the number of bits allowed for representation in hardware. A message update function specifically defined as part of the invention, is used to determine the outgoing message at the variable node, and the simple min operation along with modulo 2 sum of signs is used at the check node. A general methodology is provided to obtain the multilevel decoders, which is based on reducing failures due to trapping sets and improving the guaranteed error-correction capability of a code. Hence these decoders improve the iterative decoding process on finite length graphs and have the potential to outperform the standard floating-point BP decoder in the error floor region.

Abstract: Embodiments provide a method comprising estimating a first set of log-likelihood ratio (LLR) values for a plurality of memory cells of a memory; based on the first set of LLR values, performing a first error correcting code (ECC) decoding operation; in response to determining a failure of the first ECC decoding operation, generating, by adjusting the first set of LLR values, a second set of LLR values for the plurality of memory cells; and based on the second set of LLR values, performing a second ECC decoding operation.

Abstract: Systems and methods are provided to generate soft information related to the threshold voltage of a memory cell. A range of threshold voltages for the memory cell is divided into subregions of threshold voltage values herein referred to as bins. An output of the memory cell in response to an applied reference signal is measured. The applied reference signal includes a voltage value and position information. A single bin is identified based on the position information of the reference signal. The identified bin is split into more than one bin based on the output of the memory cell and the voltage value of the reference signal. The newly split bins and all the other bins that were not split are assigned new bin indices.

Abstract: The present disclosure includes systems and techniques relating to non-volatile memory. A described system, for example, includes a non-volatile memory structure having a plurality of multi-level memory cells, a processing device, and a controller. The controller is configured to map a first portion of a first set of consecutive bits of a data segment to a first page associated with the plurality of multi-level memory cells, and map a second portion of the first set of consecutive bits of the data segment to a second page associated with the plurality of multi-level memory cells. The first page is associated with bits of a first significance, and the second page is associated with bits of a second significance.

Abstract: Systems and methods for encoding and decoding for communications or storage systems utilizing coded modulation are provided. A first portion of data is encoded with a first at least one encoding scheme. A second portion of the data id encoded with a second encoding scheme. A coset is selected from a plurality of cosets based at least in part on the encoded first portion of the data, where the plurality of cosets corresponds to a partition of a signal constellation. A signal vector is selected within the selected coset based at least in part on the encoded second portion of the data.

Abstract: A system including a reference voltage module to select a first reference voltage between a first threshold voltage corresponding to a first state of a memory cell and a second threshold voltage corresponding to a second state of the memory cell, a second reference voltage less than the first reference voltage, and a third reference voltage greater than the first reference voltage. The system includes a read module to perform a first read operation to determine a state of the memory cell based on the first reference voltage, and in response to a first failure to decode data read from the memory cell in the first read operation, perform a second read operation to determine the state based on the second reference voltage and a third read operation to determine the state based on the third reference voltage.

Abstract: In this invention, a new class of finite precision multilevel decoders for low-density parity-check (LDPC) codes is presented. These decoders are much lower in complexity compared to the standard belief propagation (BP) decoder. Messages utilized by these decoders are quantized to certain levels based on the number of bits allowed for representation in hardware. A message update function specifically defined as part of the invention, is used to determine the outgoing message at the variable node, and the simple min operation along with modulo 2 sum of signs is used at the check node. A general methodology is provided to obtain the multilevel decoders, which is based on reducing failures due to trapping sets and improving the guaranteed error-correction capability of a code. Hence these decoders improve the iterative decoding process on finite length graphs and have the potential to outperform the standard floating-point BP decoder in the error floor region.