A decoding system and method of a non-volatile memory are provided in which information regarding a characteristic of a non-volatile memory is used to determine an initial log-likelihood-ratio (LLR) table from among a number of LLR tables. The decoding is then performed using the determined initial LLR table.

Hard errors are determined for an unsuccessful decoding of codeword bits read from NAND memory cells via a read channel and input to a low-density parity check (LDPC) decoder. A bit error rate (BER) for the hard errors is estimated and BER for the read channel is estimated. Hard error regions are found using a single level cell (SLC) reading of the NAND memory cells. A log likelihood ratio (LLR) mapping of the codeword bits input to the LDPC decoder is changed based on the hard error regions, the hard error BER, and/or the read channel BER.

A method of soft decoding received signals. The method comprising defining quantisation intervals for a signal value range, determining a number of bits in each quantisation interval that are connected to unsatisfied constraints, providing, the number of bits in each quantisation interval that are connected to unsatisfied constraints, as an input to a trained model, wherein the trained model has been trained to cover an operational range of a device for soft decoding of signals, determining, using the trained model, a log likelihood ratio for each quantisation interval, and performing soft decoding using the log likelihood ratios.

Various embodiments include an on-die error correction code (ECC) system that preserves rectangular symbols of arbitrary size and shape, where the dimensions of the symbol are powers of two. Further, the on-die ECC system preserves symbols that include multiple rectangles of arbitrary size and shape, where the dimensions of each rectangle are powers of two, and where the vertical and horizontal offset between consecutive rectangles are also powers of two. If the on-die ECC system miscorrects a memory bit, then the miscorrection is constrained or restricted to the same symbol that includes the other error bits. Therefore, all error bits, including the miscorrected bit, are in the same symbol. As a result, a user ECC system, such as a symbol-based ECC system, can correct and detect any number of errors within a single symbol, even when the on-die ECC system miscorrects a memory bit.

Provided is an optical transmission/reception device including: an error correction encoding unit configured to encode a sequence to be transmitted with one type of LDPC code; and an error correction decoding unit configured to decode a received sequence encoded with the LDPC code. The error correction decoding unit performs decoding processing for the received sequence based on a check matrix of an LDPC convolutional code. The decoding processing is windowed decoding processing, which is performed by using a window extending over one or more check submatrices. A window size of the window and a decoding iteration count are configured to be variable, and the window size and the decoding iteration count are input from a control circuit connected to the error correction decoding unit.

Methods, systems, and media for decoding data are described. A sequence of read-level voltages for decoding operations may be determined based on a trend of decoding success indicators, including a first decoding success indicator and a second decoding success indicator. The first decoding success indicator is obtained from a more recent successful decoding operation. The first one of the sequence may be set to a read-level voltage of the first decoding success indicator. If the read-level voltage of the first decoding success indicator is less than a read-level voltage of the second decoding success indicator, then the trend is decreasing, and the second one of the sequence may be set to a read-level voltage less than that of the first one of the sequence. After executing one or more decoding operations, the decoding success indicators may be updated based on the read-level voltage of the current successful decoding operation.

A determination is made that error-correcting code functionality detected a first number of erroneous bits within a memory device. Bits within the memory device are evaluated to identify a subset of the bits as candidate bits. The candidate bits are evaluated to determine whether the error-correcting code functionality returns a non-error state, where no error correction is performed, based upon one or more combinations of candidate bits being inverted. Responsive to the error-correcting code functionality returning the non-error state for only one combination of the one or more combinations of candidate bits being inverted, the one combination of candidate bits is corrected.

Techniques related to a QoS-aware decoder architecture for data storage are described. In an example, QoS specifications include a QOS latency specification indicative of an acceptable latency for completing the processing of a data read command. The decoder may store this QOS latency specification. In operation, the decoder generates a latency measurement indicative of the actual latency for the processing. If a comparison of the latency measurement and QOS latency specification indicates a violation of the QOS latency specification, the decoder can terminate the decoding and generate a decoding failure.

Method and apparatus for managing data in a non-volatile memory (NVM) of a storage device, such as a solid-state drive (SSD). In some embodiments, flash memory cells are arranged along word lines to which read voltages are applied to sense programmed states of the memory cells, with the flash memory cells along each word line being configured to concurrently store multiple pages of data. An encoder circuit is configured to apply error correction encoding to input data to form code words having user data bits and code bits, where an integral number of the code words are written to each page. A reference voltage calibration circuit is configured to randomly select a single selected code word from each page and to use the code bits from the single selected code word to generate a set of calibrated read voltages for the associated page.

An illustrative embodiment of this disclosure is an apparatus, including a memory, a processor in communication with the memory, and a decoder. The processor is configured to train a classifier, calculate one or more features of a codeword, predict an outcome of decoding the codeword with the decoder, and determine, using the classifier, whether the outcome satisfies a predetermined threshold. In some embodiments, based on the outcome, the processor selects a set of decoder parameters to improve decoder performance.