Abstract: A method of operating a memory controller includes classifying a plurality of memory cells in an erase state into a plurality of groups, based on erase state information about the plurality of memory cells in the erase state; setting at least one target program state for at least some memory cells from among memory cells included in at least one of the plurality of groups; and programming the at least some memory cells for which the at least one target program state has been set, to a program state other than the at least one target program state from among the plurality of program states.

Abstract: A method of decoding a low density parity check (LDPC) code, includes dividing a parity check matrix of the LDPC code, into a plurality of sub blocks. The method further includes, for each of a plurality of decoding iterations, performing a node operation of each of target sub blocks among the plurality of sub blocks, the target sub blocks corresponding to a present decoding iteration among the plurality of decoding iterations, in a decoding schedule, estimating a reliability of each of the target sub blocks, based on a result of the node operation of each of the target sub blocks, and adjusting the decoding schedule, based on the reliability of each of the target sub blocks.

Abstract: An method of operating a nonvolatile memory device including a plurality of memory cells comprises receiving a read command from an external device, in response to the read command, performing, based on a reference voltage, a first cell counting operation with respect to the plurality of memory cells, adjusting at least one read voltage of first through nth read voltages (where n is a natural number greater than 1) based on a first result of the first cell counting operation, and performing, based on the adjusted at least one read voltage, a read operation corresponding to the read command with respect to the plurality of memory cells.

Abstract: A method of operating a memory controller includes classifying a plurality of memory cells in an erase state into a plurality of groups, based on erase state information about the plurality of memory cells in the erase state; setting at least one target program state for at least some memory cells from among memory cells included in at least one of the plurality of groups; and programming the at least some memory cells for which the at least one target program state has been set, to a program state other than the at least one target program state from among the plurality of program states.

Abstract: An operating method of a memory controller that individually controls a plurality of memory units includes reading respective segments from the plurality of memory units based on a plurality of control signals; generating an output codeword based on the segments; performing error correction decoding on the output codeword; when a result of the error correction decoding indicates success, updating at least one of a plurality of accumulated error pattern information respectively corresponding to the plurality of memory units based on the result of the error correction decoding; and when the result of the error correction decoding indicates failure, regulating at least one of the plurality of control signals based on at least one of the plurality of accumulated error pattern information.

Abstract: An error correcting circuit receives a codeword including user data and a parity code, and performs an error correction operation on the user data. The circuit includes a first buffer, a decoder, a second buffer and a processor. The first buffer stores the codeword and sequentially outputs pieces of subgroup data obtained by dividing the codeword. The decoder generates pieces of integrity data for each of the pieces of subgroup data received from the first buffer, and performs the error correction operation on the user data using the parity code. The second buffer sequentially stores the pieces of integrity data for each of the pieces of subgroup data. The processor determines whether an error is present in the codeword based on the pieces of integrity data stored in the second buffer when at least one of the pieces of integrity data is updated in the second buffer.

Abstract: An method of operating a nonvolatile memory device including a plurality of memory cells comprises receiving a read command from an external device, in response to the read command, performing, based on a reference voltage, a first cell counting operation with respect to the plurality of memory cells, adjusting at least one read voltage of first through nth read voltages (where n is a natural number greater than 1) based on a first result of the first cell counting operation, and performing, based on the adjusted at least one read voltage, a read operation corresponding to the read command with respect to the plurality of memory cells.

Abstract: A storage device is provided as follows. A nonvolatile memory device includes blocks, each block having sub-blocks erased independently. A memory controller performs a garbage collection operation on the nonvolatile memory device by selecting a garbage collection victim sub-block among the sub-blocks and erasing the selected garbage collection victim sub-block to generate a free sub-block. The memory controller selects the garbage collection victim sub-block using valid page information of each sub-block and valid page information of memory cells adjacent to each sub-block.

Abstract: A method of decoding may include performing fewer than ? 2 k - 1 k ? number of sensing operations of multilevel cells within a nonvolatile memory device, decoding pages corresponding to each of the sensing operations while correcting a channel error using an RIO code, and extracting user data from the decoded pages.

Abstract: A method of operating a memory system, having a non-volatile memory device, includes processing a response to a first request toward the memory device by using an original key, in response to the first request, generating and storing first parity data corresponding to the original key, and deleting the original key.

Abstract: A method of setting a read voltage by a memory controller and a storage device are provided. The method includes controlling a memory device to read data from memory cells by applying a test read voltage to a selected word line; receiving, from the memory device, cell count information corresponding to a read operation of the memory device, and renewing the test read voltage by using the cell count information and a cost function to find an optimum read voltage, the cost function being determined for each read voltage level; and determining a read voltage by performing the controlling of the memory device and the renewing of the test read voltage at least once.

Abstract: A method of operating a memory controller includes classifying a plurality of memory cells in an erase state into a plurality of groups, based on erase state information about the plurality of memory cells in the erase state; setting at least one target program state for at least some memory cells from among memory cells included in at least one of the plurality of groups; and programming the at least some memory cells for which the at least one target program state has been set, to a program state other than the at least one target program state from among the plurality of program states.

Abstract: An method of operating a nonvolatile memory device including a plurality of memory cells comprises receiving a read command from an external device, in response to the read command, performing, based on a reference voltage, a first cell counting operation with respect to the plurality of memory cells, adjusting at least one read voltage of first through nth read voltages (where n is a natural number greater than 1) based on a first result of the first cell counting operation, and performing, based on the adjusted at least one read voltage, a read operation corresponding to the read command with respect to the plurality of memory cells.

Abstract: A low-density parity check (LDPC) decoder may include a variable node processing unit and a check node processing unit. The check node processing unit includes memory elements storing a check node value. The memory elements are interconnected through two or more paths, and each of the paths may include a total or partial cyclic permutation of the memory elements to transmit the check node value.

Abstract: A method of operating a memory controller includes classifying a plurality of memory cells in an erase state into a plurality of groups, based on erase state information about the plurality of memory cells in the erase state; setting at least one target program state for at least some memory cells from among memory cells included in at least one of the plurality of groups; and programming the at least some memory cells for which the at least one target program state has been set, to a program state other than the at least one target program state from among the plurality of program states.

Abstract: An error correction device includes a low density parity check (LDPC) decoder and an adaptive decoding controller. The LDPC decoder iteratively performs LDPC decoding on data by using a decoding parameter. The adaptive decoding controller calculates an error rate depending on a result of the LDPC decoding and adjusts the decoding parameter depending on the error rate.

Abstract: A method of operating a memory controller that performs decoding by using a parity check matrix corresponding to a convolution-type low density parity check (LDPC) code includes receiving a codeword from at least one memory device, the codeword including a first sub-codeword and a second sub-codeword; decoding a first sub-codeword into first data by using first sliding windows in a first direction, set based on a first sub-matrix included in the parity check matrix and associated with the first sub-codeword; and decoding a second sub-codeword into second data by using second sliding windows in a second direction, set based on a second sub-matrix included in the parity check matrix and associated with the second sub-codeword.

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 of decoding a low density parity check (LDPC) code, includes dividing a parity check matrix of the LDPC code, into a plurality of sub blocks. The method further includes, for each of a plurality of decoding iterations, performing a node operation of each of target sub blocks among the plurality of sub blocks, the target sub blocks corresponding to a present decoding iteration among the plurality of decoding iterations, in a decoding schedule, estimating a reliability of each of the target sub blocks, based on a result of the node operation of each of the target sub blocks, and adjusting the decoding schedule, based on the reliability of each of the target sub blocks.

Abstract: A polar code encoding and decoding method includes generating a first and second sub-codewords. The sub-codewords correspond to pre-codewords, and the pre-codewords have a shared data aspect. The sub-codewords provide useful error-recovery for data stored in a memory. When data is read from the memory, decoding takes place. The data read operation may include hard decision decoding, soft decision decoding, or hard decision decoding followed by soft decision decoding. In the method, the shared data aspect is used to decode a first sub-codeword for which decoding was not initially successful. An apparatus is also provided.