Abstract: A decoder includes a channel mapper configured to generate a plurality of channel reception values based on hard decision information and soft decision information, a strong error detector configured to determine whether a strong error has occurred using a plurality of check node messages and the channel reception values and to correct the channel reception values according to a determination result to produce corrected channel reception values, a variable node unit configured to generate a plurality of variable node messages using the check node messages and the corrected channel reception values, and a check node unit configured to generate the check node messages using the variable node messages. The variable node unit includes a plurality of variable nodes and the check node unit includes a plurality of check nodes.

Abstract: A method and system of recovering data includes reading reference codewords, which have code correlation with a target codeword, from a memory device when an error-correcting code (ECC) decoding process for a decoder input of the target codeword has failed. A decoder input of a corrected target codeword is generated based on an operation process using the target codeword and the reference codewords. An ECC decoding process is performed again on the decoder input of the corrected target codeword.

Abstract: A method of operating a decoder, which has variable nodes and check nodes, includes receiving variable-to-check (V2C) messages from the variable nodes using a first check node among the check nodes. The number of messages having a specific magnitude among the V2C messages is counted. The magnitude of a check-to-variable (C2V) message to be transmitted to a first variable node, among the variable nodes, is determined based on the count value and the magnitude of a V2C message of the first variable node.

Abstract: An operating method of an error correction decoder includes receiving data, setting initial log-likelihood values of variable nodes, and decoding the received data by updating a log-likelihood value of a selected variable node by use of a minimum value and a minimum candidate value associated with the selected variable node. The minimum value indicates a minimum value of absolute values of log-likelihood values of first variable nodes sharing a check node with the selected variable node and including the selected variable node. The minimum candidate value indicates one from among absolute values of log-likelihood values of second variable nodes that has the smallest value greater than the minimum value. The second variable nodes are selected later than one from among the first variable nodes corresponding to the minimum value.

Abstract: A method of decoding data of a non-volatile memory device is provided. The method includes a first decoding operation of reading first hard decision data from the non-volatile memory device using a first hard decision read level and performing decoding using the first hard decision data; a second decoding operation of reading first soft decision data from the non-volatile memory device when the decoding fails in the first decoding operation, and performing decoding using the first soft decision; and a third decoding operation of changing from the first hard decision read level to a second hard decision read level when the decoding fails in the second decoding operation, reading second hard decision data using the second hard decision read level, and performing decoding either using the second hard decision data or using both the second hard decision data and the first soft decision data.

Abstract: A redundant array of inexpensive disks (RAID) controller of a RAID storage system that includes one or more storage devices includes an error correction code (ECC) result manager configured to manage information of ECC result indicators when a data chunk that includes one or more ECC data units having an uncorrectable ECC error is read from among a plurality of data chunks dispersively stored in the one or more storage devices, each of the plurality of data chunks including a plurality of ECC data units, the ECC result indicators respectively indicating whether the plurality of ECC data units included in the plurality of data chunks has an uncorrectable ECC error; and an uncorrectable error counter configured to calculate a number of ECC result indicators indicating an uncorrectable ECC error among ECC result indicators corresponding to ECC data units having a same order in each of the plurality pluralit.y of data chunks.

Abstract: A method of operating a memory system includes receiving information data corresponding to a second program unit that is a part of a first program unit and a write request for the information data from a host; generating a codeword by performing error correction code (ECC) encoding on the received information data such that a partial parity bit corresponding to the information data among all parity bits of the codeword is updated; and providing a memory device with the generated codeword and a write command regarding the codeword.

Abstract: A method of estimating a deterioration state of a memory device comprises reading data from selected memory cells connected to a selected wordline of a memory cell array by applying to the selected wordline a plurality of distinct read voltages having values corresponding to at least one valley of threshold voltage distributions of the selected memory cells, generating quality estimation information indicating states of the threshold voltage distributions using the data read from the selected memory cells, and determining a deterioration state of a storage area including the selected memory cells based on the generated quality estimation information.

Abstract: An operating method of an error correction decoder includes receiving data, setting initial log-likelihood values of variable nodes, and decoding the received data by updating a log-likelihood value of a selected variable node by use of a minimum value and a minimum candidate value associated with the selected variable node. The minimum value indicates a minimum value of absolute values of log-likelihood values of first variable nodes sharing a check node with the selected variable node and including the selected variable node. The minimum candidate value indicates one, greater than the minimum value and smallest, from among absolute values of log-likelihood values of second variable nodes that are selected later than one, corresponding to the minimum value, from among the first variable nodes.

Abstract: A method of decoding data of a non-volatile memory device is provided. The method includes a first decoding operation of reading first hard decision data from the non-volatile memory device using a first hard decision read level and performing decoding using the first hard decision data; a second decoding operation of reading first soft decision data from the non-volatile memory device when the decoding fails in the first decoding operation, and performing decoding using the first soft decision; and a third decoding operation of changing from the first hard decision read level to a second hard decision read level when the decoding fails in the second decoding operation, reading second hard decision data using the second hard decision read level, and performing decoding either using the second hard decision data or using both the second hard decision data and the first soft decision data.

Abstract: A low-density parity-check (LDPC) decoding method includes exchanging messages between check nodes and variable nodes based on scheduling information representing an order of exchanging messages between the check nodes and the variable nodes for an LDPC decoding, and performing the LDPC decoding based on the exchanged messages, wherein the scheduling information is determined by manipulating at least one of an order of the check nodes and an order of the variable nodes in an LDPC bipartite graph.

Abstract: A method of estimating a deterioration state of a memory device comprises reading data from selected memory cells connected to a selected wordline of a memory cell array by applying to the selected wordline a plurality of distinct read voltages having values corresponding to at least one valley of threshold voltage distributions of the selected memory cells, generating quality estimation information indicating states of the threshold voltage distributions using the data read from the selected memory cells, and determining a deterioration state of a storage area including the selected memory cells based on the generated quality estimation information.

Abstract: An iterative decoding method is disclosed and includes sequentially executing a number of iterative decoding cycles in relation to a parity check equation until the parity check equation is resolved, or a maximum number N of iterative decoding cycles is reached, during execution of the number of iterative decoding cycles, storing in a data buffer minimum estimated values for a set of variable nodes corresponding to a minimum number of bit errors, and outputting the minimum estimated values stored in the data buffer as a final decoding result when the number of iterative decoding cycles reaches N.

Abstract: A decoding method includes performing a first decoding method and performing a second decoding method when decoding of the first decoding method fails. The first decoding method includes updating multiple variable nodes and multiple check nodes using probability values of received data. The second decoding method includes selecting at least one variable node from among the multiple variable nodes; correcting probability values of data received in the selected at least one variable node; updating the variable nodes and the check nodes using the corrected probability values; and determining whether decoding of the second decoding method is successful.

Abstract: A decoder includes multiple decoder stages and a controller. The decoder stages perform decoding operations with respect to a received signal using corresponding different decoding algorithms. The controller determines whether the decoding operation performed by one of the decoder stages with respect to the received signal is successful, and controls the decoding operation of each of the other decoder stages in response to a result of the determination.

Abstract: A decoding method includes performing a first decoding method and performing a second decoding method when decoding of the first decoding method fails. The first decoding method includes updating multiple variable nodes and multiple check nodes using probability values of received data. The second decoding method includes selecting at least one variable node from among the multiple variable nodes; correcting probability values of data received in the selected at least one variable node; updating the variable nodes and the check nodes using the corrected probability values; and determining whether decoding of the second decoding method is successful.

Abstract: An iterative decoding method is disclosed and includes sequentially executing a number of iterative decoding cycles in relation to a parity check equation until the parity check equation is resolved, or a maximum number N of iterative decoding cycles is reached, during execution of the number of iterative decoding cycles, storing in a data buffer minimum estimated values for a set of variable nodes corresponding to a minimum number of bit errors, and outputting the minimum estimated values stored in the data buffer as a final decoding result when the number of iterative decoding cycles reaches N.

Abstract: A decoder includes multiple decoder stages and a controller. The decoder stages perform decoding operations with respect to a received signal using corresponding different decoding algorithms. The controller determines whether the decoding operation performed by one of the decoder stages with respect to the received signal is successful, and controls the decoding operation of each of the other decoder stages in response to a result of the determination.