A method is proposed for decoding read bits including information bits from memory cells of a solid state drive. The method comprises determining a reliability indication indicative of a reliability of the read bits, and iterating the following sequence of steps: soft decoding the read bits based on said reliability indication in order to obtain said information bits, determining at least one among a time indication indicative of a time elapsed since a last writing of the memory cells and a temperature indication indicative of a temperature of the memory cells, and applying at least one among said time indication and said temperature indication to said reliability indication.

A corresponding solid state drive is also proposed.

A method is proposed for decoding bits stored in memory cells of a solid state drive. Each memory cell comprises a floating gate transistor adapted to store a bit pattern, among a plurality of possible bit patterns, when programmed at a threshold voltage associated with that bit pattern, each threshold voltage being variable over the memory cells thereby defining, for each bit pattern, a corresponding threshold voltage distribution. The bit pattern of each memory cell comprises first and second bits, and the solid state drive is suitable for reading the bit patterns based on fixed reference voltages, each one designed to discern between two respective adjacent threshold voltage distributions, and on additional reference voltages different from the fixed reference voltages. The solid state drive is capable of soft decoding the read bit patterns based on soft information. The method comprises:

reading the first and second bits of the memory cells based on the fixed reference voltages, to obtain read first bits and read second bits, and

soft decoding the read first bits, wherein the soft information exploited for soft decoding the read first bits are based on the read second bits.

A corresponding solid state drive is also proposed.

A method of power saving for a low-density parity check (LDPC) decoder includes: during each decoding iteration, determining a syndrome weight; and using the determined syndrome weight to set an optimal clock frequency for the LDPC decoding. The LDPC decoding is hard decision hard decoding using a bit-flipping algorithm. When it is determined that the syndrome weights begin to overlap, the method further includes: performing one more iteration in hard decision hard decoding mode; providing a power boost to the LDPC decoder; and switching to hard decision soft decoding mode.

An error correction circuit includes: a first error correction encoder for generating a plurality of row-codewords by performing first error correction encoding on each of a plurality of messages; a second error correction encoder for generating a plurality of column-codewords; a first error correction decoder for performing first error correction decoding on each of read row-vectors corresponding to the plurality of row-codewords, and outputting a soft information of the first error correction decoding; and a second error correction decoder for determining whether each of m-bit symbols in read column-vectors corresponding to the column-codewords is reliable, based on the soft information corresponding to each of the p-bit symbols, and performing second error correction decoding on the read column-vectors, based on the determination of whether each of the m-bit symbols is reliable.

A non-volatile memory system may be configured to generate a codeword with first-type parity bits and one or more second-type parity bits. If a storage location in which the codeword is to be stored includes one or more bad memory cells, the bit sequence of the codeword may be arranged so that at least some of the second-type parity bits are stored in the bad memory cells. During decoding, a first set of syndrome values may be determined for a first set of check nodes and a second set of syndrome values may be determined for a second set of check nodes. In some examples, a syndrome weight used for determining if convergence is achieved may be calculated using check nodes that are unassociated with the second-type parity bits.

In an illustrative example, a method includes sensing at least a portion of a representation of a convolutional low-density parity-check (CLDPC) codeword stored at a memory of a data storage device. The method further includes receiving the portion of the representation of the CLDPC codeword at a controller of the data storage device. The method further includes performing one or more management operations associated with the memory based on an estimated number of errors of the portion of the representation of the CLDPC codeword.

The current invention relates to an encoder for converting a set of data words into a data block having a header section, a checksum section and a payload section; the encoder comprising: a header inserter arranged to insert a header pattern in the data block; a checksum calculator arranged to calculate a checksum of the set of data words; a data word converter arranged to convert the set of data words into a set of obfuscated data words being a result of applying an exclusive or operation between the set of data words and the checksum.

Methods, systems, and apparatuses include receiving a codeword stored in a memory device. The codeword has bits from defective bit locations and non-defective bit locations. A syndrome of a current copy of the codeword is determined. Channel information for non-defective bit locations is determined using the current copy of the codeword and the received codeword from the memory device. Energy function values are determined for bits of the codeword using the syndrome of the current copy. Determining the energy function values includes using the channel information for bits in non-defective bit locations and omitting channel information for bits in defective bit locations. One or more bits of the codeword are flipped in response to the energy function values for the one or more bits satisfying a bit flipping criterion. A corrected codeword that results from the flipping of the bits is returned.

A method is provided for determining log-likelihood ratio (LLR) for soft decoding based on information obtained from hard decoding, in a storage system configured to perform hard decoding and soft decoding of low-density parity-check (LDPC) codewords. The method includes performing hard decoding of codewords in a page, the hard decoding including a first hard read and one or more re-reads using predetermined hard read threshold voltages, and grouping memory cells in the page into a plurality of bins based on the read threshold voltages for the first hard read and the one or more re-reads. The method also includes computing parity checksum and one's count for memory cells in each bin, and determining LLR for each bin of memory cells based on read data, checksums, and one's count for each bin.

A decoding method includes: receiving a plurality of subcarrier signals each including encoded data; acquiring a predetermined amount of data from each of the plurality of subcarrier signals; correcting errors in the plurality of subcarrier signals by performing decoding arithmetic processing on the respective predetermined amounts of data acquired from the plurality of subcarrier signals in a time-division manner; and causing the decoding arithmetic processing to be consecutively performed on each of the predetermined amounts of data a predetermined number of times.