Abstract: A low density parity check decoder includes a variable node processor operable to generate variable node to check node messages and to calculate perceived values based on check node to variable node messages, a check node processor operable to generate the check node to variable node message vectors and to calculate checksums based on the variable node to check node messages, and a convergence detector and bit map generator operable to convergence of the perceived values and to generate at least one bit map that identifies variable nodes that are connected to check nodes with unsatisfied parity checks.

Abstract: Described embodiments provide a media controller that performs error correction on data read from a solid-state media. The media controller receives a read operation from a host device to read one or more given read units of the solid-state media. The media controller reads the data for the corresponding read units from the solid-state media employing initial values for one or more read threshold voltages. Only if a disparity between an actual number of bits at a given logic level included in the read data and an expected number of bits at the given logic level included in the read data has not reached a predetermined threshold, the media controller decodes the read data and provides the decoded data to the host device.

Abstract: An indication of a page type which failed error correction decoding is received. A threshold to adjust is selected from a plurality of thresholds based at least in part on the page type. A third adjusted threshold associated with the page type is generated, including by: determining a first number of flipped bits using a first adjusted threshold associated with the page type, determining a second number of flipped bits using a second adjusted threshold associated with the page type, and generating the third adjusted threshold using the first number of flipped bits and the second number of flipped bits.

Abstract: An instruction to write to a location in the Flash memory is received. It is determining if the Flash memory exposes a level placement setting associated with defining what voltage range corresponds to what level. In the event it is determined that the Flash memory exposes a level placement setting, an accurate coarse write is performed on the location, including by configuring the level placement setting to be a first value, and after the accurate coarse write is performed on the location, a fine write is performed on the location, including by configuring the level placement setting to be a second value, in response to receiving the instruction.

Abstract: One or more locations in a plurality of data bit sequences that do not satisfy parity and are associated with data bit sequences that are unable to be successfully error correction decoded are determined. Soft information associated with the determined locations is modified and error correction decoding using the modified soft information is performed.

Abstract: An indication to store a data value in Flash memory is received. An accurate coarse write is performed on the Flash memory, including by: storing a first voltage level in the Flash memory and setting a configuration setting of the Flash memory to a first setting. The first voltage level, when interpreted using the configuration setting at the first setting, corresponds to the data value. A fine write is performed on the Flash memory, including by: storing a second voltage level in the Flash memory and setting the configuration setting of the Flash memory to a second setting. The second voltage level, when interpreted using the configuration setting at the second setting, corresponds to the data value.

Abstract: A method and system for constructing a generator matrix is disclosed. The method includes: receiving a parity check matrix H, wherein the parity check matrix H includes multiple circulant sub-matrices; rearranging the parity check matrix H by column and row permutations to obtain a rearranged parity check matrix H?; and constructing the generator matrix G based on the rearranged parity check matrix H?.

Abstract: An apparatus having a first circuit and a second circuit is disclosed. The first circuit may be configured to generate (i) a plurality of symbols and (ii) a plurality of decision values both in response to detecting an encoded codeword. The second circuit may be configured to (i) generate a plurality of probabilities to flip one or more of the symbols based on the decision values, (ii) generate a modified probability by merging two or more of the probabilities of an unreliable position in the symbols and (iii) generate a decoded codeword by decoding the symbols using an algebraic soft-decision technique in response to the modified probability.

Abstract: A method of optimizing solid state drive (SSD) soft retry voltages comprises limiting a number of voltage reads and properly spacing and determining the reference voltage at which each voltage is read based on desired Bit Error Rate (BER) and channel throughput. The method determines each reference voltage for a number of soft retry voltage reads based on a hard decision read. The spacing between each read reference voltage is constant since each SSD type requires a number of reads for an accurate presentation of soft retry voltages. The voltage distance between each successive read is limited to a multiple of the constant spacing while the multiple is based on success or failure of the first read. The method determines a limited number of reads, the constant spacing between reads, and a desired reference voltage for each read, thereby increasing valuable throughput of the channel and decreasing BER.

Abstract: Old user data, old metadata, and old error correction parity information are received. New metadata corresponding to the old user data is generated. The old metadata and the new metadata are combined to obtain combined metadata. New error correction parity information is generated using the combined metadata. The old error correction parity information and new error correction parity information are combined to obtain combined error correction parity information. The old user data, new metadata, and combined error correction parity information are stored in solid state storage.

Abstract: An indication to store a data value in Flash memory is received. An accurate coarse write is performed on the Flash memory, including by: storing a first voltage level in the Flash memory and setting a configuration setting of the Flash memory to a first setting. The first voltage level, when interpreted using the configuration setting at the first setting, corresponds to the data value. A fine write is performed on the Flash memory, including by: storing a second voltage level in the Flash memory and setting the configuration setting of the Flash memory to a second setting. The second voltage level, when interpreted using the configuration setting at the second setting, corresponds to the data value.

Abstract: Methods and apparatus are provided for integrated-interleaved Low Density Parity Check (LDPC) coding and decoding. Integrated-interleaved LDPC encoding is performed by obtaining at least a first data element and a second data element; systematically encoding the at least first data element using a submatrix H0 of a sparse parity check matrix H1 to obtain at least a first codeword; truncating the at least first data element to obtain at least a first truncated data element; systematically encoding the at least second data element and the at least first truncated data element using the sparse parity check matrix H1 to obtain a nested codeword; and generating a second codeword based at least in part on a combination of the first codeword and the nested codeword. Integrated-interleaved LDPC decoding is also provided.

Abstract: An indication of a page type which failed error correction decoding is received. A threshold to adjust is selected from a plurality of thresholds based at least in part on the page type. A third adjusted threshold associated with the page type is generated, including by: determining a first number of flipped bits using a first adjusted threshold associated with the page type, determining a second number of flipped bits using a second adjusted threshold associated with the page type, and generating the third adjusted threshold using the first number of flipped bits and the second number of flipped bits.

Abstract: A set of data associated with a page in flash storage is received. Error correction decoding is performed on the set of data; if event error correction decoding fails, it is determined whether the page is a most significant bit (MSB) page or a least significant bit (LSB) page. If it is determined the page is a MSB page, one or more MSB read thresholds are adjusted and the is re-read page using the adjusted MSB read threshold(s). If it is determined the page is a LSB page, one or more LSB read thresholds are adjusted and the page is re-read using the adjusted LSB read threshold(s).

Abstract: An indication to store a data value in Flash memory is received. An accurate coarse write is performed, including by storing a first voltage level in the Flash memory and setting a configuration setting to a first setting. The first voltage level, when interpreted using the configuration setting at the first setting, corresponds to the data value. A fine write is performed, including by storing a second voltage level in the Flash memory and setting the configuration setting of the Flash memory to a second setting. The second voltage level, when interpreted using the configuration setting at the second setting, corresponds to the data value.

Abstract: An apparatus having a first circuit and a second circuit is disclosed. The first circuit may be configured to generate (i) a plurality of symbols and (ii) a plurality of decision values both in response to detecting an encoded codeword. The second circuit may be configured to (i) generate a plurality of probabilities to flip one or more of the symbols based on the decision values, (ii) generate a modified probability by merging two or more of the probabilities of an unreliable position in the symbols and (iii) generate a decoded codeword by decoding the symbols using a list decode technique in response to the modified probability.

Abstract: An error locator polynomial is incrementally generated by flipping a bit pattern Yi at a symbol Xi an initial dataword to obtain a first test error pattern. A bit pattern Yj at a symbol Xj within the first test error pattern is flipped to obtain a second test error pattern, wherein i?j.

Abstract: An apparatus having a first circuit and a second circuit is disclosed. The first circuit may be configured to generate (i) a plurality of symbols and (ii) a plurality of decision values both in response to detecting an encoded codeword. The second circuit may be configured to (i) generate a plurality of probabilities to flip one or more of the symbols based on the decision values, (ii) generate a modified probability by merging two or more of the probabilities of an unreliable position in the symbols and (iii) generate a decoded codeword by decoding the symbols using a list decode technique in response to the modified probability.

Abstract: A set of data associated with a page in flash storage is received. Error correction decoding is performed on the set of data; if event error correction decoding fails, it is determined whether the page is a most significant bit (MSB) page or a least significant bit (LSB) page. If it is determined the page is a MSB page, one or more MSB read thresholds are adjusted and the is re-read page using the adjusted MSB read threshold(s). If it is determined the page is a LSB page, one or more LSB read thresholds are adjusted and the page is re-read using the adjusted LSB read threshold(s).

Abstract: An apparatus having a first circuit and a second circuit is disclosed. The first circuit may be configured to generate (i) a plurality of symbols and (ii) a plurality of decision values both in response to detecting an encoded codeword. The second circuit may be configured to (i) generate a plurality of probabilities to flip one or more of the symbols based on the decision values, (ii) generate a modified probability by merging two or more of the probabilities of an unreliable position in the symbols and (iii) generate a decoded codeword by decoding the symbols using an algebraic soft-decision technique in response to the modified probability.