The embodiments herein describe technologies of initializing resistive memory devices (e.g., non-volatile and volatile memory devices). In one method, a first voltage is applied across a resistance change material of a memory cell to form an initial filament and multiple cycles are performed to condition the initial filament. Each of the multiple cycles includes: applying a second voltage with a first polarity across the resistance change material; and applying a third voltage with a second polarity across the resistance change material.

In various embodiments. an electronic circuit is provided. The electronic circuit may include at least one memory cell and a control circuit configured to determine a formation state of the at least one memory cell and set a predefined function to a predefined state of executability (e.g., enabled or disabled) based on the determined formation states. For example, the predefined function may be set to the predefined state of executability only if the determined formation states of two or more memory cells match a predefined formation state pattern, or only if a minimum number or fraction of two or memory cells are in a predefined formation state. The formation state is either unformed or formed, wherein the unformed state is an electrically isolated state, and the formed state is a state into which an initially unformed memory cell is transformable and in which the formed memory cell is repeatedly switchable between a state of low electrical resistivity and a state of high electrical resistivity.

In certain aspects, a circuit for ZQ resistor calibration can include a first input configured to receive a first default configuration. The circuit can also include a second input configured to receive a first calibration value based on a first comparison. The circuit can further include a first output configured to provide a first resistor code for a first resistor category. The circuit can additionally include a second output configured to provide a second resistor code for a second resistor category different from the first resistor category. The circuit can also include a first logic circuit configured to receive a signal from the first input and a signal from the second input, and provide a signal to the first output. The signal to the first output can include the first resistor code. The first resistor code can be different from the second resistor code.

Numerous embodiments of circuitry for a set-while-verify operation and a reset-while verify operation for resistive random access memory cells are disclosed. In one embodiment, a set-while-verify circuit for performing a set operation on a selected RRAM cell in the array applies a combination of voltages or current to a bit line, word line, and source line associated with the selected RRAM cell and stops said applying when the set operation is complete. In another embodiment, a reset-while-verify circuit for performing a reset operation on a selected RRAM cell in the array applies a combination of voltages or current to a bit line, word line, and source line associated with the selected RRAM cell and stops said applying when the reset operation is complete.

A memristor-based circuit includes a voltage generator that applies a series of voltage pulses to a memristor to progressively change the resistance of the memristor. A comparator: receives an input electrical value; receives an electrical value based on the resistance of the memristor; compares the received values; and, based on the comparison, enables the application of the voltage pulses to the memristor by the voltage generator until a defined condition is satisfied. This circuit can be used to enable the memristor to be programmed to a desired resistance value, such as for use as a non-volatile memory. It can also enable the resistance of one memristor to be replicated to another memristor. By counting the number of applied voltage pulses, the circuit can be used as an encoder or analog-to-digital converter. Other variants of the circuit enable construction of a decoder or digital-to-analog converter, and an authentication circuit.

An embodiment of a non-volatile memory device is proposed. Said memory device comprises a matrix of memory cells; each memory cell is individually programmable to at least a first logic level and individually erasable to a second logic level. The memory device further comprises partition means for logically subdividing the matrix into a plurality of subspaces; each subspace comprises at least one respective memory cell. The memory device further comprises selection means for selecting a subspace, operative means for performing an operation on all the memory cells of the selected subspace, and means for dynamically modifying the number of subspaces and/or the number of memory cells included in each subspace.

A data-write device includes a write driver that causes a current to flow through a current path including an MTJ element or the other current path including the MTJ element in accordance with writing data to be written, thereby writing the write data into the MTJ element, a write completion detector which monitors the voltage at a first connection node or a second connection node in accordance with the write data after the writing of the write data into the MTJ element starts, detects the completion of writing of the write data based on the voltage at either node, and supplies a write completion signal indicating the completion of data write, and a write controller that terminates the writing of the write data into the MTJ element in response to the write completion signal supplied from the write completion detector.

Various embodiments provide methods for configuring a phase-change random-access memory (PCRAM) structures, such as PCRAM operating in a single-level-cell (SLC) mode or a multi-level-cell (MLC) mode. Various embodiments may support a PCRAM structure being operating in a SLC mode for lower power and a MLC mode for lower variability. Various embodiments may support a PCRAM structure being operating in a SLC mode or a MLC mode based at least in part on an error tolerance for a neural network layer.

A memory apparatus includes a write driver, a sense amplifier and a reference voltage setting circuit. The write driver programs a set data or a reset data into a memory cell. The sense amplifier generates an output signal by sensing data stored in the memory cell. The reference voltage setting circuit sets a set reference voltage having a lowest level to satisfy a set data distribution, and sets a set-up reset reference voltage from the set reference voltage.

A memory device according to an embodiment includes first and second interconnects, memory cells, and a control circuit. In a first process, the control circuit applies a write voltage of a first direction to a memory cell coupled to selected first and second interconnects, and applies a write voltage of a second direction to a memory cell coupled to the selected first interconnect and a non-selected second interconnect. In second processes of first to m-th trial processes, the control circuit applies the write voltage of the second direction to the memory cell coupled to the selected first and second interconnects, and omits a write operation in which the memory cell coupled to the selected first interconnect and the non-selected second interconnect is targeted.