According to one embodiment, a storage device includes a nonvolatile memory and a controller. The controller is configured to read data from the nonvolatile memory by applying a read voltage to the nonvolatile memory. The controller is configured to correct the read voltage based on a difference between a measured value of a bit number obtained when the data is read from the nonvolatile memory by applying the read voltage to the nonvolatile memory and an expected value of the bit number.

A storage device includes a non-volatile memory including a plurality of blocks, a buffer memory that stores a plurality of on-cell counts, which are generated by reading memory cells connected to a plurality of reference word lines of the plurality of blocks by using a read level, and an artificial neural network model, and a controller that inputs an on-cell count corresponding to a target block among the plurality of on-cell counts and a number of a target word line of the target block to the artificial neural network model, and infers a plurality of read levels for reading data of memory cells connected to the target word line using the artificial neural network model.

A method for operating a data storage device includes determining appropriateness of a first read bias for adjacent target threshold voltage distributions among threshold voltage distributions for a plurality of memory cells; and if it is determined that the first read bias is inappropriate, determining a second read bias.

Methods, systems, and devices for operating a ferroelectric memory cell or cells are described. A memory array may be operated in a half density mode, in which a subset of the memory cells is designated as reference memory cells. Each reference memory cell may be paired to an active memory cell and may act as a reference signal when sensing the active memory cell. Each pair of active and reference memory cells may be connected to a single access line. Sense components (e.g., sense amplifiers) associated with reference memory cells may be deactivated in half density mode. The entire memory array may be operated in half density mode, or a portion of the array may operate in half density mode and the remainder of the array may operate in full density mode.

One or more of multiple metrics for multiple logical page types of the memory device are determined. Each of the metrics is indicative of a number of bit errors associated with a particular logical page type of the multiple logical page types. A current page margin associated with a first logical page type of the multiple logical page types is modified to determine a modified page margin based at least in part on a ratio using one or more of the multiple metrics. The current page margin associated with the first logical page type is adjusted in accordance with the modified page margin.

A memory device that, in certain embodiments, includes a memory element coupled to a bit-line and a quantizing circuit coupled to the memory element via the bit-line. In some embodiments, the quantizing circuit includes an analog-to-digital converter having an input and output and a digital filter that includes memory. The input of the analog-to-digital converter may be coupled to the bit-line, and the output of the analog-to-digital converter may be coupled to the digital filter.

Methods, systems, and devices for operating a ferroelectric memory cell or cells are described. A memory array may be operated in a half density mode, in which a subset of the memory cells is designated as reference memory cells. Each reference memory cell may be paired to an active memory cell and may act as a reference signal when sensing the active memory cell. Each pair of active and reference memory cells may be connected to a single access line. Sense components (e.g., sense amplifiers) associated with reference memory cells may be deactivated in half density mode. The entire memory array may be operated in half density mode, or a portion of the array may operate in half density mode and the remainder of the array may operate in full density mode.

A power-off period estimating method for a solid state storage device is provided. A memory array of a non-volatile memory of the solid state storage device includes plural blocks. Firstly, a first quality parameter of a first block of the plural blocks is calculated before the solid state storage device is powered off. When the first block is corrected at a first time counting value, a first read voltage set of the first block is acquired and the first time counting value is recorded. Then, the first block is corrected after the solid state storage device is powered on, so that a second read voltage set of the first block is acquired. Then, a power-off period is calculated according to the first quality parameter, the first read voltage set, the second read voltage set and the first time counting value.

Disclosed herein are related to a circuit and a method of reading or sensing multiple bits of data stored by a multi-level cell. In one aspect, a first reference circuit is selected from a first set of reference circuits, and a second reference circuit is selected from a second set of reference circuits. Based at least in part on the first reference circuit and the second reference circuit, one or more bits of multiple bits of data stored by a multi-level cell can be determined. According to the determined one or more bits, a third reference circuit from the first set of reference circuits and a fourth reference circuit from the second set of reference circuits can be selected. Based at least in part on the third reference circuit and the fourth reference circuit, additional one or more bits of the multiple bits of data stored by the multi-level cell can be determined.

A semiconductor device storing data as a multilevel potential is provided. The semiconductor device includes a memory cell, first and second reference cells, first and second sense amplifiers, and first to third circuits. The first circuit has a function of outputting, to a first wiring and a third wiring, a first potential corresponding to a first signal output from the memory cell. The second circuit has a function of outputting, to a second wiring, a first reference potential corresponding to a second signal output from the first reference cell. The third circuit has a function of outputting, to the fourth wiring, a second reference potential corresponding to a third signal output from the second reference cell when a second switch is in an off state. The first sense amplifier refers to the first potential and the first reference potential and changes potentials of the first wiring and the second wiring. The second sense amplifier refers to the first potential and the second reference potential and changes potentials of the third wiring and the fourth wiring.