A memory device includes a string of cells having one and more top selection cells, one or more dummy memory cells, and memory cells, and a peripheral circuit coupled to the string of cells. The peripheral circuit is configured to verify a threshold voltage of at least one of the one or more top selection cells or the one or more dummy memory cells to determine whether the at least one of the one or more top selection cells or the one or more dummy memory cells has failed. In response to the at least one of the one or more top selection cells or the one or more dummy memory cells being failed, the peripheral circuit is further configured to reset the at least one of the one or more top selection cells or the one or more dummy memory cells.

Methods, systems, and devices for monitoring and adjusting access operations at a memory device are described to support integrating monitors or sensors for detecting memory device health issues, such as those resulting from device access or wear. The monitoring may include traffic monitoring of access operations performed at various components of the memory device, or may include sensors that may measure parameters of components of the memory device to detect wear. The traffic monitoring or the parameters measured by the sensors may be represented by a metric related to access operations for the memory device. The memory device may use the metric (e.g., along with a threshold) to determine whether to adjust a parameter associated with performing access operations received by the memory device, in order to implement a corrective action.

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.

Disclosed is a memory device including a magnetic storage element. The memory device includes a memory cell array, a voltage generator, and a write driver. The memory cell array includes a first region and a second region. The memory device is configured to store a value of a first read current determined based on a value of a reference resistance for distinguishing a parallel state and an anti-parallel state of a programmed memory cell. The sensing circuit is configured to generate the first read current based on the value of the first read current and to perform a read operation on the first region based on the first read current.

A method includes replacing an address of a first normal memory cell in a first column of a first memory block with a destination address that is an address of a second normal memory cell in a second column of the first memory block, and reassigning the address of the second normal memory cell in the second column of the first memory block to an address of a first redundancy memory cell in a redundancy block of the memory device.

A method includes replacing an address of a first normal memory cell in a first column of a first memory block with a destination address that is an address of a second normal memory cell in a second column of the first memory block, and reassigning the address of the second normal memory cell in the second column of the first memory block to an address of a first redundancy memory cell in a redundancy block of the memory device.

A memory device includes: a memory cell array comprising a plurality of memory cells, the plurality of memory cells comprising a plurality of data memory cells including a first data memory cell and a plurality of backup memory cells including a first backup memory cell; a storage storing an error table configured to record errors in the plurality of data memory cells, the error table including a plurality of error table entries, each error table entry corresponding to one of the plurality of data memory cell and having an address and a failure count; and a controller configured to replace the first data memory cell with the first backup memory cell based on the error table.

A memory device includes: a memory cell array comprising a plurality of memory cells, the plurality of memory cells comprising a plurality of data memory cells including a first data memory cell and a plurality of backup memory cells including a first backup memory cell; a storage storing an error table configured to record errors in the plurality of data memory cells, the error table including a plurality of error table entries, each error table entry corresponding to one of the plurality of data memory cell and having an address and a failure count; and a controller configured to replace the first data memory cell with the first backup memory cell based on the error table.

A memory apparatus includes an address decoding circuit configured to output a test redundancy address based on an address that is transmitted from a memory controller; and a redundancy address check circuit configured to determine whether the test redundancy address is replacing a failed address, in order to perform an ECC test operation by using the test redundancy address.

According to various embodiments, a semiconductor memory device includes a substrate that includes a memory cell region and a test region. The semiconductor memory device further includes an active pattern on the memory cell region, a source/drain pattern on the active pattern, a dummy pattern on the test region, a first gate electrode on the dummy pattern, a first common contact, and a first wiring layer. The first wiring layer includes a first test line electrically connected to the first common contact. The first common contact includes a first contact pattern in contact with the dummy pattern, and a first gate contact connected to the first gate electrode. The first gate contact includes a body and a protrusion part. A lowermost level of a top surface of the active pattern is lower than a lowermost level of a top surface of the dummy pattern.