A memory access module for performing memory access management of a storage device includes a plurality of storage cells. Each storage cell has a number of possible bit(s) directly corresponding to possible states of the storage cell. The memory access module further includes: sensing means for performing a plurality of sensing operations, wherein a first sensing operation corresponds to a first sensing voltage, and each subsequent sensing operation corresponds to a sensing voltage determined according to a result of the previous sensing operation; generating means for using the plurality of sensing operations to generate a first digital value and a second digital value of a storage cell; processing means for using the first and the second digital value to obtain soft information of a same bit stored in the storage cell; and decoding means for using the soft information to perform soft decoding.

The present invention provides a data storage device including a flash memory and a controller. The flash memory has a plurality of single-level-cell units and a plurality of triple-level cell units. The controller performs a first predetermined number of read processes on a second predetermined number of specific single-level-cell units to program data stored in the second predetermined number of specific single-level-cell units into a specific triple-level cell unit of the triple-level cell units and determines whether any of the second predetermined number of specific single-level-cell units has not been read successfully by any of the read processes when the specific triple-level cell unit cannot be read successfully.

A memory cell includes an input coupled to a read line, an output coupled to a circuit ground, a bi-polar memristor, and at least one address switch coupled to an address line to select the memory cell. A memory includes the bi-polar memristor and a one-way current conducting device, wherein the one-way current conducting device is positioned between the memristor cell output and the circuit ground, or between the read line and the memristor cell input.

Some embodiments include apparatuses and methods using first and second select gates coupled in series between a conductive line and a first memory cell string of a memory device, and third and fourth select gates coupled in series between the conductive line and a second memory cell string of the memory device. The memory device can include first, second, third, and fourth select lines to provide first, second, third, and fourth voltages, respectively, to the first, second, third, and fourth select gates, respectively, during an operation of the memory device. The first and second voltages can have a same value. The third and fourth voltages can have different values.

Methods, systems, and devices for write operation techniques for memory systems are described. In some memory systems, write operations performed on target memory cells of the memory device may disturb logic states stored by one or more adjacent memory cells. Such disturbances may cause reductions in read margins when accessing one or more memory cells, or may cause a loss of data in one or more memory cells. The described techniques may reduce aspects of logic state degradation by supporting operational modes where a host device, a memory device, or both, refrains from writing information to a region of a memory array, or inhibits write commands associated with write operations on a region of a memory array.

Disclosed in some examples are methods, systems, devices, and machine-readable mediums that provide for techniques for scrambling and/or updating meta-data that enable an efficient internal copyback operation. In some examples, improved data distribution techniques decouple the scrambling key from a physical address to allow for copyback operations while maintaining data distribution requirements across a memory device. The controller may generate a seed value that is used by a scrambling algorithm to scramble the host-data and meta-data prior to the data being written. The seed value is then encoded and written to the page with encoded versions of the scrambled user data and meta-data—the random seed is written without scrambling the random seed.

Adaptive read threshold voltage tracking techniques are provided that employ bit error rate estimation based on a non-linear syndrome weight mapping. An exemplary device comprises a controller configured to determine a bit error rate for at least one of a plurality of read threshold voltages in a memory using a non-linear mapping of a syndrome weight to the bit error rate for the at least one of the plurality of read threshold voltages.

A memory system includes a nonvolatile memory which comprises a plurality of memory cells capable of storing 4-bit data represented by first to fourth bits by sixteen threshold regions, and a memory controller configured to cause the nonvolatile memory to execute a first program for writing data of the first bit, the second bit, and the fourth bit and then causes the nonvolatile memory to execute a second program for writing data of the third bit. In fifteen boundaries existing between adjacent threshold regions among the first to sixteenth threshold regions, a maximum value of the number of first boundaries used for determining a value of the data of the first bit, the number of second boundaries used for determining a value of the data of the second bit, the number of third boundaries used for determining a value of the data of the third bit.

Methods, systems, and devices for storing and reading data at a memory device are described. A memory device may utilize one or more storage states to store data within a data word. The memory device may exhibit higher data leakage or more power consumption when storing or reading a first storage state compared to storing or reading one or more other storage states. In some cases, the memory device may generate a second data word corresponding to a first data word by modifying each symbol type of the first data word to generate a different symbol type for the second data word. A memory device may reduce the occurrence of a storage state associated with large data leakage, or high-power consumption, or both. Further, the memory device may generate and store an indicator indicating the transformation of a corresponding data word.

Concurrent access of multiple memory cells in a cross-point memory array is disclosed. In one aspect, a forced current approach is used in which, while a select voltage is applied to a selected bit line, an access current is driven separately through each selected word line to concurrently drive the access current separately through each selected memory cell. Hence, multiple memory cells are concurrently accessed. In some aspects, the memory cells are accessed using a self-referenced read (SRR), which improves read margin. Concurrently accessing more than one memory cell in a cross-point memory array improves bandwidth. Moreover, such concurrent accessing allows the memory system to be constructed with fewer, but larger cross-point arrays, which increases array efficiency. Moreover, concurrent access as disclosed herein is compatible with memory cells such as MRAM which require bipolar operation.