Systems and methods for precision writing of weight values to a memory capable of storing multiple levels in each cell are disclosed. Embodiments include logic to compare an electrical parameter read from a memory cell with a base reference and an interval reference, and stop writing once the electrical parameter is between the base reference and the base plus the interval reference. The interval may be determined using a greater number of levels than the number of stored levels, to prevent possible overlap of read values of the electrical parameter due to memory device variations.

A memory device includes a plurality of memory cells, each memory cell including a switching element and a data storage element having a phase change material, and each memory cell connected to one of a plurality of wordlines and to one of a plurality of bitlines, a decoder circuit configured to determine at least one of the plurality of memory cells as a selected memory cell, and a programming circuit configured to input a program current to the selected memory cell to perform a program operation, to detect a holding voltage of the selected memory cell, and to adjust a magnitude of the program current based on the detected holding voltage. The selected memory cell is turned off when a voltage across the selected memory cell is lower than the holding voltage.

Memory systems and memory programming methods are described. According to one aspect, a memory system includes program circuitry configured to provide a program signal to a memory cell to program the memory cell from a first memory state to a second memory state, detection circuitry configured to detect the memory cell changing from the first memory state to the second memory state during the provision of the program signal to the memory cell to program the memory cell, and wherein the program circuitry is configured to alter the program signal as a result of the detection and to provide the altered program signal to the memory cell to continue to program the memory cell from the first memory state to the second memory state.

Structures and methods for a multi-bit phase change memory are disclosed herein. A method includes establishing a write-reference voltage that incrementally ramps over a write period. The increments of the write-reference voltage correspond to discrete resistance states of a storage cell of the multi-bit phase change memory.

Structures and methods for a multi-bit phase change memory, are provided herein. A method includes establishing a write-reference voltage that incrementally ramps over a write period. The increments of the write-reference voltage correspond to discrete resistance states of a storage cell of the multi-bit phase change memory.

A memory driving device includes a first switch, a voltage detecting circuit, and a switch array. The first switch includes a first output terminal and a first control terminal, and the first output terminal provides an output voltage for a memory unit. The voltage detecting circuit is coupled to the first output terminal, and configured to detect the output voltage, and generates a control signal according to the output voltage, wherein the control signal changes in real time according to the changing of the output voltage. The switch array includes a plurality of second switches, and the second switches are coupled to the first control terminal. At least one of the second switches is turned on according to the control signal so as to adjust a voltage of the first control terminal for regulating a waveform of the output voltage.

A memory device includes: a memory bit cell; a write circuit, coupled to the memory bit cell, and configured to use a first voltage to transition the memory bit cell to a first logic state by changing a respective resistance state of the memory bit cell, and compare a first current flowing through the memory bit cell with a first reference current; and a control logic circuit, coupled to the write circuit, and configured to determine whether the first logic state is successfully written into the memory bit cell based on a read-out logic state of the memory bit cell and the comparison between the first current and first reference current.

A method for operating a differential memory includes: operating a main memory module differentially while executing a first program; copying first logic data from a first submodule of the main memory module to an auxiliary memory module; storing third logic data associated with a second program in a second submodule of the main memory module by overwriting second logic data associated with the first program, while maintaining the first logic data contained in the first submodule of the main memory module unaltered, where the second logic data are complementary to the first logic data; when a request for reading the first logic data is received during the storing of the third logic data in the second submodule of the main memory module, reading the first logic data from the auxiliary memory module; and executing the first or second programs by operating the main memory module in single-ended mode.

A data write-in method and a non-volatile memory are provided. The data write-in method includes: providing a reset voltage to a plurality of selected memory cells according to a first flag, and recursively performing a reset process for the plurality of selected memory cells; setting a second flag according to a plurality of first verification currents of the plurality of selected memory cells; and under a condition that the second flag is set: providing a set voltage to the plurality of selected memory cells according to a resistance of the plurality of selected memory cells; and setting the first flag according to a plurality of second verification currents of the plurality of selected memory cells.

A method for facilitating erase or program operations on two-terminal memory devices includes substantially simultaneously initiating erase cycle or program cycle for two-terminal memory devices from a first plurality of two-terminal memory devices, monitoring erase detect or program detect conditions for each of the two-terminal memory devices, and before detecting erase detect or program detect conditions for all of the two-terminal memory devices, the method includes detecting an erase detect or a program detect condition for the first two-terminal memory device from the first plurality of two-terminal memory devices, and initiating an erase cycle or a program for a second two-terminal memory device for a second plurality of two-terminal memory devices, in response to detecting the erase detect or program detect condition for the first two-terminal memory device.