A determination that a first programming operation has been performed on a particular memory cell can be made. A determination can be made, based on one or more threshold criteria, whether the particular memory cell has transitioned from a state associated with a decreased error rate to another state associated with an increased error rate. In response to determining that the particular memory cell has transitioned from the state associated with the decreased error rate to the another state associated with the increased error rate, an operation can be performed on the particular memory cell to transition the particular memory cell from the another state associated with the increased error rate to the state associated with the decreased error rate.

Methods, systems, and devices for operating memory cell(s) using a direct-input column redundancy scheme are described. A device that has read data from data planes may replace data from one of the planes with redundancy data from a data plane storing redundancy data. The device may then provide the redundancy data to an error correction circuit coupled with the data plane that stored the redundancy data. An output of the error correction circuit may be used to generate syndrome bits, which may be decoded by a syndrome decoder. The syndrome decoder may indicate whether a bit of the data should be corrected by selectively reacting to inputs based on the type of data to be corrected. For example, the syndrome decoder may react to a first set of inputs if the data bit to be corrected is a regular data bit, and react to a second set of inputs if the data bit to be corrected is a redundant data bit.

A semiconductor device that writes data to, instead of a defective memory cell, another memory cell is provided. The semiconductor device includes a first circuit and a second circuit over the first circuit; the first circuit corresponds to a memory portion and includes a memory cell and a redundant memory cell; a second circuit corresponds to a control portion and includes a third circuit and a fourth circuit. The memory cell is electrically connected to the third circuit, the redundant memory cell is electrically connected to the third circuit, and the third circuit is electrically connected to the fourth circuit. The fourth circuit has a function of sending data to be written to the memory cell or the redundant memory cell to the third circuit, and the third circuit has a function of bringing the memory cell and the fourth circuit into a non-conduction state and the redundant memory cell and the fourth circuit into a conduction state to send the data to the redundant memory cell when the memory cell is a defective cell.

Systems and methods of screening memory cells by modulating bitline and/or wordline voltage. In a read operation, the wordline may be overdriven or underdriven as compared to a nominal operating voltage on the wordline. In a write operation, the one or both of the bitline and wordline may be overdriven or underdriven as compared to a nominal operating voltage of each. A built-in self test (BIST) system for screening a memory array has bitline and wordline margin controls to modulate bitline and wordline voltage, respectively, in the memory array.

A repair circuit includes: a plurality of redundant memory cells, each redundant memory cell being configured with a state signal; and a repair module connected to the plurality of redundant memory cells and configured to determine target memory cells from the redundant memory cells based on the state signals and repair defective memory cells through the target memory cells. The target memory cells are in one-to-one correspondence to the defective memory cells. The repair module can repair, at each of multiple repair stages, different defective memory cells, the plurality of redundant memory cells being shared at the multiple repair stages.

An example system includes a processing resource and a switch board coupled to a system under test (SUT) and the processing resource. The SUT includes a memory device. The switch board can be configured to provide power to the SUT, communicate a first signal from the SUT to the processing resource, and provide a second signal to the SUT that simulates an input to the SUT during operation of the SUT. The processing resource can be configured to receive a function, selected from a library of functions, to execute during a test of the memory device and cause the switch board to provide the second signal during the test of the SUT.

A memory system includes a non-volatile memory and a memory controller. The memory controller is configured to read a received word from the non-volatile memory, estimate noise by using a plurality of different models for estimating the noise included in the received word to obtain a plurality of noise estimation values, select one noise estimation value from the plurality of noise estimation values, update the received word by using a value obtained by subtracting the selected noise estimation value from the read received word, and decode the updated received word by using a belief-propagation method.

A memory apparatus and method of operation is provided. The apparatus has blocks each including non-volatile storage elements. Each of the non-volatile storage elements stores a threshold voltage representative of an element data. The apparatus also includes one or more managing circuits configured to erase at least one of the blocks in an erase operation and program the element data in a program operation. The one or more managing circuits are also configured to proactively identify ones of the blocks as potential bad blocks and selectively apply stress to the ones of the blocks identified as the potential bad blocks and determine whether the potential bad blocks should be retired from the erase and program operations and put in a grown bad block pool or released to a normal block pool used for the erase and program operations based on a judgment after selectively applying the stress.

A method of testing a non-volatile memory (NVM) array includes obtaining a current distribution of a subset of NVM cells of the NVM array, the current distribution including first and second portions corresponding to respective logically high and low states of the subset of NVM cells, programming an entirety of the NVM cells of the NVM array to one of the logically high or low states, determining an initial bit error rate (BER) by performing first and second pass/fail (P/F) tests on each NVM cell of the NVM array, and using the current distribution to adjust the initial BER rate. Each of obtaining the current distribution, programming the entirety of the NVM cells, and performing the first and second P/F tests is performed while the NVM array is heated to a target temperature.

According to one embodiment, a memory system includes a semiconductor memory and a controller. The memory system is capable of executing a first operation and a second operation. In the first operation, the controller issues a first command sequence, the semiconductor memory applies a first voltage to a first word line and applies a second voltage to a second word line to read data from the first memory, and the read data is transmitted to the controller from the semiconductor memory. In the second operation, the controller issues a second command sequence, the semiconductor memory applies a third voltage to the first word line and applies a fourth voltage to the second word line, and data held in the memory cell array is left untransmitted to the controller.