A memory system includes a memory device having a memory cell array, and a controller. The memory cell array includes a plurality of first units and at least one second unit. The second unit includes the plurality of first units. The controller counts a first number of times of read operation for each of the plurality of first units, and, in response to the first number of times for one first unit among the plurality of first units reaching a first value, updates a second number of times for the second unit that includes the one first unit. In response to the second number of times reaching a second value, the controller determines whether to rewrite data stored in at least one of the first units included in the second unit.

A memory device, a memory system including the memory device, and a method of operating the memory device are described. The memory device includes a memory cell array including a plurality of planes, a peripheral circuit configured to perform a read operation including a channel initialization operation on a selected memory block among a plurality of memory blocks included in each of the plurality of planes, and a control logic configured to control the peripheral circuit to perform the read operation including the channel initialization operation, and the control logic sets an activation time of the channel initialization operation based on an read mode of the read operation.

A read operation is performed on a memory device in accordance with a pass-through voltage setting that defines a pass-through voltage applied to one or more cells of the memory device during read operations. A number of zero bits read from the memory device based on the read operation are counted and compared with a threshold value. Based on the number of zero bits exceeding the threshold value, the pass-through voltage is increased by adjusting the pass-through voltage setting.

A semiconductor memory device includes a memory cell array, a page buffer, and control logic. The memory cell array includes a plurality of memory cells for storing data. The page buffer is coupled to at least one memory cell among the plurality of memory cells through a bit line and is configured to store data in the at least one memory cell. The control logic is configured to control an operation of the page buffer. The page buffer includes a first transistor coupled between the bit line and a first node, a second transistor coupled between the bit line and an external power voltage terminal, and an internal operation circuit coupled to the first node.

In certain aspects, a memory device includes a memory cell array having rows of memory cells, word lines respectively coupled to the rows of memory cells, and a peripheral circuit coupled to the memory cell array through the word lines. Each memory cell is configured to store a piece of N-bits data in one of 2.sup.N levels, where N is an integer greater than 1. The level corresponds to one of 2.sup.N pieces of N-bits data. The peripheral circuit is configured to program, in a first pass, a row of target memory cells, such that each target memory cell is programmed into one of K intermediate levels based on the corresponding piece of N-bits data, wherein 2.sup.N−1<K<2.sup.N. The peripheral circuit is also configured to program, in a second pass after the first pass, the row of target memory cells, such that each target memory cell is programmed into one of the 2.sup.N levels based on the corresponding piece of N-bits data.

An operating method of a memory device, comprises: a program operation of applying a program voltage to a selected word line to program selected memory cells connected to the selected word line, a first verification operation of applying a first verification voltage to the selected word line and applying a first verification pass voltage to unselected word lines to verify a first program state of the selected memory cells, and a second verification operation of applying a second verification voltage to the selected word line and applying a second verification pass voltage to the unselected word lines to verify a second program state higher than the first program state.

Crossbar arrays with reduced disturbance and methods for programming the same are disclosed. In some implementations, an apparatus comprises: a plurality of rows; a plurality of first columns; a plurality of second columns; a plurality of devices. Each of the plurality of devices is connected among one of the plurality of rows, one of the plurality of first columns, and one of the plurality of second columns. The device further comprises a shared end on the plurality of first columns or the plurality of the second columns connecting to the plurality of the devices in the same row or column; the shared end is grounding or holds a stable voltage potential. In some implementations, one of the devices is: a RRAM, a floating date, a phase change device, an SRAM, a memristor, or a device with tunable resistance. In some implementations the stable voltage potential is a constant DC voltage.

The present disclosure provides a circuit for detecting leakage between word lines in a memory device. The circuit includes a first and a second coupling capacitor. A first terminals of the first and second coupling capacitors are connected to a first word line and a second word line, respectively. The first terminals of the first and second coupling capacitors are also connected to a first and a second voltage supply, respectively. The circuit further includes a comparator, wherein a first input of the comparator is connected to a second terminal of the first coupling capacitor and a second input of the comparator is connected to a second terminal of the second coupling capacitor. The comparator is configured to send alarm signal when a differential voltage between the first input and the second input of the comparator is larger than a hysteresis level of the comparator.

Countermeasure method for programming a non-defective plane of a non-volatile memory experiencing a neighbor plane disturb, comprising, once a first plane is determined to have completed programming of a current state but where not all planes have completed the programming, a loop count is incremented and a determination is made as to whether the loop count exceeds a threshold. If so, programming of the incomplete plane(s) is ceased and programming of the completed plane(s) is resumed by suspending the loop count and bit scan mode, and, on a next program pulse, applying a pre-determined rollback voltage to decrement a program voltage bias. The loop count and bit scan mode are resumed once a threshold voltage level equals a program voltage bias when the loop count was last incremented. BSPF criterion is applied for each programmed state. Advancement to the next loop only occurs if a programmed state is determined incomplete.

The present disclosure provides a three-dimensional NAND memory device, comprising a first NAND string including a first channel corresponding to a first cell to be inhibited to program, and a controller configured to control a word line driver and a bit line driver to do the following operations: prior to applying a program voltage to a selected word line, charging a first bit line electrically coupling with the first channel to a first voltage level for charging the first channel to the first voltage level, charging an array common source electrically coupling with the first bit line for further charging the first channel to a second voltage level higher than the first voltage level, and cutting off the electrical coupling between the first bit line and the first channel for preparing to apply the program voltage to the selected word line.