Encoders and decoders are provided for memory systems. An encoder scrambles data bits corresponding to a logical page, selected from among multiple logical pages, using a plurality of random sequences, to generate a plurality of scrambled sequences; selects, as an encoded sequence, a scrambled sequence among the plurality of scrambled sequences; and provides a memory device with the encoded sequence to store the encoded sequence in multiple level cells. The selected scrambled sequence has the lowest number of logical high values among the plurality of scrambled sequences.

Various implementations described herein refer to a device having an encoder coupled to memory. The ECC encoder receives input data from memory built-in self-test circuitry, generates encoded data by encoding the input data and by adding check bits to the input data, and writes the encoded data to memory. The device may have an ECC decoder coupled to memory. The ECC decoder reads the encoded data from memory, generates corrected data by decoding the encoded data and by extracting the check bits from the encoded data, and provides the corrected data and double-bit error flag as output. The ECC decoder has error correction logic that performs error correction on the decoded data based on the check bits, wherein if the error correction logic detects a multi-bit error in the decoded data, the error correction logic corrects the multi-bit error in the decoded data to provide the corrected data.

Various implementations described herein refer to a device having an encoder coupled to memory. The ECC encoder receives input data from memory built-in self-test circuitry, generates encoded data by encoding the input data and by adding check bits to the input data, and writes the encoded data to memory. The device may have an ECC decoder coupled to memory. The ECC decoder reads the encoded data from memory, generates corrected data by decoding the encoded data and by extracting the check bits from the encoded data, and provides the corrected data and double-bit error flag as output. The ECC decoder has error correction logic that performs error correction on the decoded data based on the check bits, wherein if the error correction logic detects a multi-bit error in the decoded data, the error correction logic corrects the multi-bit error in the decoded data to provide the corrected data.

Methods, systems, and devices for masked training and analysis with a memory array are described. A memory device may operate in a first mode in which a maximum transition avoidance (MTA) decoder for a memory array of the memory device is disabled. During the first mode, the memory device may couple an input node of the MTA decoder with a first output node of a first decoder, such as a first pulse amplitude modulation (PAM) decoder. The memory device may operate in a second mode in which the MTA decoder for the memory array is enabled. During the second mode, the memory device may couple the input node of the MTA decoder with a second output node of a second decoder, such as a second PAM decoder.

A semiconductor apparatus includes a semiconductor chip, with the semiconductor chip including a modular region and a test circuit. The modular region includes a plurality of modular areas each including a memory cell array with redundant bit lines and a peripheral memory area storing at least redundant addresses. The test circuit retrieves the redundant addresses intrinsic to the semiconductor chip. The distribution of the redundant addresses is randomly formed related to a part or an entirety of the modular area of the modular region. The distribution of the retrieved redundant addresses is irreversible, with a random number representing physical properties intrinsic to the semiconductor chip and providing copy protection. When another semiconductor chip uses the distribution of the retrieved redundant addresses the another semiconductor chip will malfunction. The test circuit outputs a random number generated from the distribution of the retrieved redundant addresses according to a specification code received from a physical-chip-identification measuring device.

A semiconductor apparatus includes a semiconductor chip, with the semiconductor chip including a modular region and a test circuit. The modular region includes a plurality of modular areas each including a memory cell array with redundant bit lines and a peripheral memory area storing at least redundant addresses. The test circuit retrieves the redundant addresses intrinsic to the semiconductor chip. The distribution of the redundant addresses is randomly formed related to a part or an entirety of the modular area of the modular region. The distribution of the retrieved redundant addresses is irreversible, with a random number representing physical properties intrinsic to the semiconductor chip and providing copy protection. When another semiconductor chip uses the distribution of the retrieved redundant addresses the another semiconductor chip will malfunction. The test circuit outputs a random number generated from the distribution of the retrieved redundant addresses according to a specification code received from a physical-chip-identification measuring device.

A computer-implemented method for sorting non-volatile random access memories (NVRAMS) includes testing a failure metric for each of a plurality of NVRAMS over a plurality of testing sessions to capture failure metric data that corresponds to the plurality of NVRAMS. The method also includes determining a trend in the failure metric as a function of testing cycles for each of the plurality of NVRAMS from the failure metric data, and separating the plurality of NVRAMS into groups based on the trend in the failure metric as a function of testing cycles. A corresponding computer program product and computer system are also disclosed herein.

The semiconductor memory device includes a memory cell array, a peripheral circuit and a control logic. The memory cell array includes a plurality of memory cells. The peripheral circuit performs a program operation for the plurality of memory cells in the memory cell array. The control logic controls the peripheral circuit and the memory cell array such that, during the program operation for the plurality of memory cells, pre-bias voltages are applied to a plurality of word lines coupled to the plurality of memory cells to precharge channel regions of the plurality of memory cells. Furthermore, different pre-bias voltages are applied to the plurality of word lines depending on the relative positions of the word lines.

The semiconductor memory device includes a memory cell array, a peripheral circuit and a control logic. The memory cell array includes a plurality of memory cells. The peripheral circuit performs a program operation for the plurality of memory cells in the memory cell array. The control logic controls the peripheral circuit and the memory cell array such that, during the program operation for the plurality of memory cells, pre-bias voltages are applied to a plurality of word lines coupled to the plurality of memory cells to precharge channel regions of the plurality of memory cells. Furthermore, different pre-bias voltages are applied to the plurality of word lines depending on the relative positions of the word lines.

A memory device, a memory system, and corresponding methods are provided. The memory device includes a non-volatile random access memory. The non-volatile memory includes a suspect bit register configured to store addresses of bits that are determined to have had errors. The non-volatile memory further includes a bad bit register configured to store addresses of bits that both (i) appeared in the suspect bit register due to a first error and (ii) are determined to have had a second error. Hence, the memory device overcomes the aforementioned intrinsic write-error-rate by identifying the bad bits so they can be fused out, thus avoiding errors during use of the non-volatile random access memory.