A location of at least one fail bit to be repaired in a memory block of a memory is extracted from at least one memory test on the memory block. An available repair resource in the memory for repairing the memory block is obtained. It is checked, using machine learning, whether the at least one fail bit is unrepairable, according to the location of the at least one fail bit, and the available repair resource. When the checking indicates that the at least one fail bit is not unrepairable, it is determined whether a Constraint Satisfaction Problem (CSP) containing a plurality of constraints is solvable. The constraints correspond to the location of the at least one fail bit in the memory block, and the available repair resource. In response to determining that the CSP is not solvable, the memory block is marked as unrepairable or the memory is rejected.

A location of at least one fail bit to be repaired in a memory block of a memory is extracted from at least one memory test on the memory block. An available repair resource in the memory for repairing the memory block is obtained. It is checked, using machine learning, whether the at least one fail bit is unrepairable, according to the location of the at least one fail bit, and the available repair resource. When the checking indicates that the at least one fail bit is not unrepairable, it is determined whether a Constraint Satisfaction Problem (CSP) containing a plurality of constraints is solvable. The constraints correspond to the location of the at least one fail bit in the memory block, and the available repair resource. In response to determining that the CSP is not solvable, the memory block is marked as unrepairable or the memory is rejected.

In a method of testing a nonvolatile memory device including a first semiconductor layer in which and a second semiconductor layer is formed prior to the first semiconductor layer, circuit elements including a page buffer circuit are provided in the second semiconductor layer, an on state of nonvolatile memory cells which are not connected to the page buffer circuit is mimicked by providing a conducting path between an internal node of a bit-line connection circuit connected between a sensing node and a bit-line node of the page buffer circuit and a voltage terminal to receive a first voltage, a sensing and latching operation with the on state being mimicked is performed in the page buffer circuit and a determination is made as to whether the page buffer circuit operates normally is made based on a result of the sensing and latching operation.

A memory device includes a memory cell array and a transmitter, wherein the transmitter includes a pulse amplitude modulation (PAM) encoder configured to generate a PAM-n first input signal (where n is an integer greater than or equal to 4) from data read from the memory cell array; a pre-driver configured to generate a second input signal based on the first input signal and based on a calibration code signal, and output the second input signal using a first power voltage; and a driver configured to output a PAM-n DQ signal using a second power voltage lower than the first power voltage in response to the second input signal.

A memory device includes a content addressable memory (CAM) block storing a plurality of stored search keys. The memory device further includes control logic that determines a first number of memory cells in at least one string of the CAM block storing one of the plurality of stored search keys, the first number of memory cells storing a first logical value, and stores a calculated parity value representing the first number of memory cells in a page cache associated with the CAM block. The control logic further reads stored parity data from one or more memory cells in the at least one string, the one or more memory cells connected to one or more additional wordlines in the CAM block, and compares the calculated parity value to the stored parity data to determine whether an error is present in the one of the plurality of stored search keys in the CAM block.

A memory device includes a memory cell array including normal memory cells and redundant memory cells; first page buffers connected to the normal memory cells through first bit lines including a first bit line group and a second bit line group and arranged in a first area corresponding to the first bit lines in a line in a first direction; and second page buffers connected to the redundant memory cells through second bit lines including a third bit line group and a fourth bit line group and arranged in a second area corresponding to the second bit lines in a line in the first direction, wherein, when at least one normal memory cell connected to the first bit line group is determined as a defective cell, normal memory cells connected to the first bit line group are replaced with redundant memory cells connected to the third bit line group.

Methods of operating a memory device are disclosed. A method may include enabling a first and second row section units a number of row section units of a memory device in response to a row address. The method may also include comparing a selected column address to a number of column addresses of defective memory cells of a first row section of the first row section unit. Moreover, in response to the selected column address matching a first column address of the number of column addresses, the method may include activating a second row section of the second row section unit, conveying a redundant column select signal to the memory array to select a redundant memory cell of the second row section. Memory devices and systems are also disclosed.

Methods of operating a memory device are disclosed. A method may include enabling a first and second row section units a number of row section units of a memory device in response to a row address. The method may also include comparing a selected column address to a number of column addresses of defective memory cells of a first row section of the first row section unit. Moreover, in response to the selected column address matching a first column address of the number of column addresses, the method may include activating a second row section of the second row section unit, conveying a redundant column select signal to the memory array to select a redundant memory cell of the second row section. Memory devices and systems are also disclosed.

A sense amplifier reference is generated with the same memory cell columns as data cells in order to match signal paths between the data and reference signals. Each row of data memory cells may have a corresponding set of reference cells, which greatly reduces the number of data cells supported by a reference, and in turn reduces the impact of process variations. A memory array may include data columns, a first reference column in the memory array configured to provide a logic 0 reference signal, and a second reference column in the memory array configured to provide a logic 1 reference signal. A circuit is configured to combine at least the logic 0 reference signal and the logic 1 reference signal to generate a reference signal for a sense amplifier to identify the data signal provided from the data columns.

A memory device includes; a memory cell array including a first memory cell region and a second memory cell region, a voltage generator configured to generate a code corresponding to a write voltage, and a write driver configured to store data in the first memory cell region in response to the code. The second memory cell region stores a value defining the write voltage, and the write voltage is determined in relation to a reference resistance distinguishing a parallel state and an anti-parallel state for the memory cells, and further in relation to an initial write voltage applied to a magnetic tunnel junction element of at least one of the memory cells.