Abstract: A homomorphic encryption operator includes: a level configuration unit configured to set an encryption level by selecting a plurality of prime numbers of different values according to a scale factor condition used for multiplication of a homomorphic encryption operation and an increase/decrease condition for increasing or decreasing consecutively selected prime numbers, and a modular multiplication operator configured to perform lightweight modular multiplication using the selected plurality of prime numbers, wherein the level configuration unit includes: a level constructor configured to select prime number sets whose number have selected Hamming weights, respectively, based on the scale factor condition and the increase/decrease condition, and wherein the level configuration unit is further configured to configure the selected prime number sets with the encryption level using a prime number table.

Abstract: In a method of error correction code (ECC) decoding, normal read data are read from a nonvolatile memory device based on normal read voltages, and a first ECC decoding is performed with respect to the normal read data. When the first ECC decoding results in failure, flip read data are read from the nonvolatile memory device based on flip read voltages corresponding to a flip range of a threshold voltage. Corrected read data are generated based on the flip read data by inverting error candidate bits included in the flip range among bits of the normal read data, and a second ECC decoding is performed with respect to the corrected read voltage. Error correction capability may be enhanced by retrying ECC decoding based on the corrected read data when ECC decoding based on the normal read data results in failure.

Abstract: Disclosed herein are operation methods of a memory controller which controls a memory device. The method includes storing write data in a first area of the memory device, extracting first error position information indicating a position of at least one error included in data stored in the first area, storing the first error position information in a second area of the memory device, reading read data from the first area of the memory device, reading the first error position information from the second area of the memory device, refining the read data based on the first error position information to generate refined data, performing soft decision decoding based on the refined data to generate corrected data, and outputting the corrected data.

Abstract: Provided are a memory controller calculating an optimal read level, a memory system including the memory controller, and an operating method of the memory controller. The memory controller includes: a processor configured to control a memory operation on the memory device; and a read level calculation module configured to: receive N counting values corresponding to N read levels generated based on a counting operation on data read by using a plurality of read levels, model at least two cell count functions having selected read levels that are selected from the N read levels as inputs, and the N counting values corresponding to the selected read levels as outputs, and calculate an optimal read level based on an optimal cell count function selected from the at least two cell count functions, wherein N is an integer equal to or greater than four, wherein the N counting values include counting values corresponding to at least four different read levels.

Abstract: In a method of predicting a remaining lifetime of the nonvolatile memory device, a read sequence is performed. The read sequence includes a plurality of read operations, and at least one of the plurality of read operations is sequentially performed until read data stored in the nonvolatile memory device is successfully retrieved. Sequence class and error correction code (ECC) decoding information are generated. A life stage of the nonvolatile memory device is determined based on at least one of the sequence class and the ECC decoding information. When it is determined that the nonvolatile memory device corresponds to a first life stage, a coarse prediction on the remaining lifetime of the nonvolatile memory device is performed. When it is determined that the nonvolatile memory device corresponds to a second life stage after the first life stage, a fine prediction on the remaining lifetime of the nonvolatile memory device is performed.

Abstract: In a method of predicting a remaining lifetime of the nonvolatile memory device, a read sequence is performed. The read sequence includes a plurality of read operations, and at least one of the plurality of read operations is sequentially performed until read data stored in the nonvolatile memory device is successfully retrieved. Sequence class and error correction code (ECC) decoding information are generated. A life stage of the nonvolatile memory device is determined based on at least one of the sequence class and the ECC decoding information. When it is determined that the nonvolatile memory device corresponds to a first life stage, a coarse prediction on the remaining lifetime of the nonvolatile memory device is performed. When it is determined that the nonvolatile memory device corresponds to a second life stage after the first life stage, a fine prediction on the remaining lifetime of the nonvolatile memory device is performed.

Abstract: A storage device includes a nonvolatile memory device and a memory controller. The memory controller receives first data from the nonvolatile memory device based on a first read command, and performs error correction on the first data. When the error correction fails, the memory controller transmits a second read command and second read voltage information to the nonvolatile memory device, receives second data from the nonvolatile memory device, transmits a third read command and third read voltage information to the nonvolatile memory device, and receives third data from the nonvolatile memory device. The memory controller adjusts an offset based on the second data and the third data, transmits a fourth read command, fourth read voltage information, and the offset to the nonvolatile memory device, receives fourth data from the nonvolatile memory device, and performs a soft decision process based on the fourth data.

Abstract: According to a method of controlling an operation of a nonvolatile memory device using machine learning, operating conditions of the nonvolatile memory device are determined by performing an inferring operation using a machine learning model. Training data that are generated based on feature information and error information are collected, where the error information indicate results of error correction code (ECC) decoding of the nonvolatile memory device. The machine learning model is updated by performing a learning operation based on the training data. Optimized operating conditions for individual user environments are provided by collecting training data in the storage system and performing the learning operation and the inferring operation based on the training data.

Abstract: A storage device includes a nonvolatile memory device and a memory controller. The memory controller receives first data from the nonvolatile memory device based on a first read command, and performs error correction on the first data. When the error correction fails, the memory controller transmits a second read command and second read voltage information to the nonvolatile memory device, receives second data from the nonvolatile memory device, transmits a third read command and third read voltage information to the nonvolatile memory device, and receives third data from the nonvolatile memory device. The memory controller adjusts an offset based on the second data and the third data, transmits a fourth read command, fourth read voltage information, and the offset to the nonvolatile memory device, receives fourth data from the nonvolatile memory device, and performs a soft decision process based on the fourth data.

Abstract: According to a method of controlling an operation of a nonvolatile memory device using machine learning, operating conditions of the nonvolatile memory device are determined by performing an inferring operation using a machine learning model. Training data that are generated based on feature information and error information are collected, where the error information indicate results of error correction code (ECC) decoding of the nonvolatile memory device. The machine learning model is updated by performing a learning operation based on the training data. Optimized operating conditions for individual user environments are provided by collecting training data in the storage system and performing the learning operation and the inferring operation based on the training data.

Abstract: The operating method of the storage device includes receiving write data to be written at the plurality of memory cells; determining whether the received write data is LSB data to be written at the plurality of memory cells; and encoding the write data according to the determination. The write data is encoded according to the write data when the write data is LSB data to be written at the plurality of memory cells. The write data is encoded according to the write data and encoding data of lower data of the write data to be written at the plurality of memory cells when the write data is not LSB data to be written at the plurality of memory cells.

Abstract: Provided are a flash memory system and a word line interleaving method thereof. The flash memory system includes a memory cell array, and a word line interleaving logic. The memory cell array is connected to a plurality of word lines. The word line (WL) interleaving logic performs an interleaving operation on WL data corresponding to at least two different wordlines and programming data, including the interleaved data, to the memory cell array.

Abstract: A default read operation is performed on a page using a default read voltage set to generate default raw data. If error bits of the default raw data are not corrected, a plurality of low-level read operations is performed on the page using a plurality of read voltage sets to generate a plurality of low-level raw data. Each read voltage set is different from the default voltage set. A read voltage set is selected from the plurality of read voltage sets as a starting voltage set, according to each low-level raw data. A high-level read operation using the selected starting voltage set is performed on the page to generate high-level raw data.

Abstract: An operating method is for a storage device that includes a nonvolatile memory and a memory controller configured to control the nonvolatile memory. The operating method may include the memory controller receiving a read request from an external device, the memory controller adjusting a read scheme according to target data indicated by the read request among data of one page of the nonvolatile memory, and the memory controller reading the target data from the nonvolatile memory according to the adjusted read scheme.

Abstract: An operating method is for a storage device that includes a nonvolatile memory and a memory controller configured to control the nonvolatile memory. The operating method may include the memory controller receiving a read request from an external device, the memory controller adjusting a read scheme according to target data indicated by the read request among data of one page of the nonvolatile memory, and the memory controller reading the target data from the nonvolatile memory according to the adjusted read scheme.

Abstract: A method of operating a nonvolatile memory device including a plurality of memory cells is provided. A default read operation is performed on a page using a default read voltage set to generate default raw data. If error bits of the default raw data are not corrected, a plurality of low-level read operations is performed on the page using a plurality of read voltage sets to generate a plurality of low-level raw data. Each read voltage set is different from the default voltage set. A read voltage set is selected from the plurality of read voltage sets as a starting voltage set, according to each low-level raw data. A high-level read operation using the selected starting voltage set is performed on the page to generate high-level raw data.

Abstract: The operating method of the storage device includes receiving write data to be written at the plurality of memory cells; determining whether the received write data is LSB data to be written at the plurality of memory cells; and encoding the write data according to the determination. The write data is encoded according to the write data when the write data is LSB data to be written at the plurality of memory cells. The write data is encoded according to the write data and encoding data of lower data of the write data to be written at the plurality of memory cells when the write data is not LSB data to be written at the plurality of memory cells.

Abstract: A data processing method is provided for processing data read from a nonvolatile memory. The data processing method includes receiving first bit data from the nonvolatile memory at a memory controller, and performing erasure decoding based on the first bit data and second bit data stored in the memory controller. The first bit data indicates a memory cell that is erasure, and the second bit data is read using a read voltage during previous error correction decoding.

Abstract: A method generating program data to be stored in a nonvolatile memory device comprises randomizing the program data, and processing the randomized program data to reduce a frequency of at least one data state among the randomized program data.

Abstract: A storage device comprises a nonvolatile memory device comprising a plurality of memory cells, and an error correction circuit configured to receive primary data and secondary data from the nonvolatile memory device and to perform a hard decision decoding operation on the primary data and further configured to perform a soft decision decoding operation on the primary data based on the secondary data. The primary data is read from the plurality of memory cells in a hard decision read operation and the secondary data is read from memory cells programmed to a specific state from among the primary data.