A method for programming at least one resistive memory cell of an array of resistive memory cells, includes a sequence of N programming cycles, N being an integer greater than or equal to 2, each programming cycle including a set procedure and a reset procedure, each set procedure including the application of a set technique chosen among a plurality of set techniques, the method including acquiring a bit error ratio value corresponding to each programming cycle for each set technique; and at each programming cycle, applying the set technique having the lowest bit error ratio value corresponding to the programming cycle.

An example apparatus can include a memory array and a memory controller. The memory array can include a first portion including a first plurality of memory cells. The memory array can further include a second portion including a second plurality of memory cells. The memory controller can be coupled to the first portion and the second portion. The memory controller can be configured to operate the first plurality of memory cells for short-term memory operations. The memory controller can be further configured to operate the second plurality of memory cells for long-term memory operations.

A variable resistive memory device includes a memory cell, a first current-applying block, a second current-applying block and a mode setting circuit. The memory cell includes a first electrode, a second electrode, and a memory layer, the memory layer interposed between the first electrode and the second electrode. The first current-applying block is configured to flow a first current to the first electrode that flows from the first electrode to the second electrode. The second current-applying block is configured to flow a second current to the second electrode that flows from the second electrode to the first electrode. The mode setting circuit is configured to selectively provide any one of the first electrode of the first current-applying block and the second electrode of the second current-applying block with a first voltage. When the memory cell is selected, the selected current-applying block, among the first current-applying block and the second current-applying block, is driven. When the first current-applying block is selected, a second voltage is applied to the second electrode. When the second current-applying block is selected, the second voltage is applied to the first electrode. The first voltage has a voltage level by a threshold voltage higher than the second voltage.

Provided is a variable resistance random-access memory for suppressing degradation of performance by recovering a memory cell that fails. A variable resistance random-access memory of the disclosure includes a memory array, a row selection circuit, a column selection circuit, a controller, an error checking and correcting (ECC) circuit, an error bit flag register, and an error bit address register. The memory array includes a plurality of memory cells. The column selection circuit includes a sense amplifier and a write driver/read bias circuit. The error bit flag register stores bits for indicating presence/absence of an error bit in a write operation. The error bit address register stores an address of the error bit. The controller recovers the error bit when a predetermined event occurs.

An example apparatus can include a memory array and a memory controller. The memory array can include a first portion including a first plurality of memory cells. The memory array can further include a second portion including a second plurality of memory cells. The memory controller can be coupled to the first portion and the second portion. The memory controller can be configured to operate the first plurality of memory cells for short-term memory operations. The memory controller can be further configured to operate the second plurality of memory cells for long-term memory operations.

According to one embodiment, there is provided a memory system including a non-volatile memory and a controller. The non-volatile memory includes a plurality of physical blocks. The controller is connected to any of the plurality of physical blocks via a plurality of channels. The controller is configured to construct a plurality of logical blocks and, read or write data from or into any of the plurality of logical blocks constructed. The logical blocks are management units in which any of the physical blocks is grouped across the plurality of channels. The controller is configured to construct the plurality of logical blocks so that a first number of defective blocks and a second number of pseudo defective blocks for shortfall defective blocks with respect to a target number of defective blocks are distributed into the plurality of logical blocks.

Broadly speaking, embodiments of the present technique provide apparatus and methods for improved wear-levelling in (volatile and non-volatile) memories. In particular, the present wear-levelling techniques comprise moving static memory states within a memory, in order to substantially balance writes across all locations within the memory.

Methods, systems, and devices for cleaning memory blocks using multiple types of write operations are described. A counter may be incremented each time a write command is received. In response to the counter reaching a threshold, the counter may be reset and a flag may be set. Each time a cleaning of a memory block is to take place, the flag may be checked. If the flag is set, the memory block may be cleaned using a second type of cleaning operation, such as one using a force write approach. Otherwise, the memory block may be cleaned using a first type of cleaning operation, such as one using a normal write approach. Once set, the flag may be reset after one or more memory blocks are cleaned using the second type of cleaning operation.

Methods, systems, and devices for signal development caching in a memory device are described. In one example, a memory device in accordance with the described techniques may include a memory array, a sense amplifier array, and a signal development cache configured to store signals (e.g., cache signals, signal states) associated with logic states (e.g., memory states) that may be stored at the memory array (e.g., according to various read or write operations). In various examples, accessing the memory device may include accessing information from the signal development cache, or the memory array, or both, based on various mappings or operations of the memory device.

The present disclosure relates to a method for accessing an array of memory cells, comprising the steps of storing user data in a plurality of memory cells of a memory array, storing, in a counter associated to the array of memory cells, count data corresponding to a number of bits in the user data having a predetermined first logic value, applying a read voltage to the memory cells to read the user data stored in the array of memory cells, applying the read voltage to the cells of the counter to read the count data stored in the counter and to provide a target value corresponding to the number of bits in the user data having the first logic value, wherein, during the application of the read voltage, the count data are read simultaneously to the user data in such a way that the target value is provided during the reading of the user data, and based on the target value of the counter, stopping the application of the read voltage when the number of bits in the user data having the first logic value corresponds to the target value. A related memory device and a related system are also disclosed.