Abstract: A method of operating a storage controller includes receiving raw data indicating a series of bits each corresponding to one of threshold voltage states, performing a first state shaping for reducing a number of first target bits of the series of bits, logical values of the first target bits being equal to a logical value of a target threshold voltage state of the threshold voltage states in a first page of plural pages, generating first indicator data that indicates the first target bits based on the first state shaping, compressing the first indicator data, and storing the compressed first indicator 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: 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: A nonvolatile memory device includes a memory cell array including a plurality of memory cells, a row decoder circuit connected to the memory cell array through a plurality of word lines; and a page buffer circuit connected to the memory cell array through bit lines. The row decoder circuit applies read voltages to a selected word line during a read operation. During a read operation performed with respect to each of N logical pages (N being a positive integer) of memory cells connected to the selected word line, the row decoder circuit applies a read voltage from among adjacent N read voltages to the selected word line without applying read voltages other than the adjacent N read voltages to the selected word line. The adjacent N read voltages include a second highest read voltage among the read voltages.

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: A nonvolatile memory device includes a memory cell array including a plurality of memory cells, a row decoder circuit connected to the memory cell array through a plurality of word lines; and a page buffer circuit connected to the memory cell array through bit lines. The row decoder circuit applies read voltages to a selected word line during a read operation. During a read operation performed with respect to each of N logical pages (N being a positive integer) of memory cells connected to the selected word line, the row decoder circuit applies a read voltage from among adjacent N read voltages to the selected word line without applying read voltages other than the adjacent N read voltages to the selected word line. The adjacent N read voltages include a second highest read voltage among the read voltages.

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.