A semiconductor memory device includes a buffer die and a plurality of memory dies. Each of the memory dies includes a memory cell array, an error correction code (ECC) engine and a test circuit. The memory cell array includes a plurality of memory cell rows, each including a plurality of volatile memory cells. The test circuit, in a test mode, generates a test syndrome and an expected decoding status flag indicating error status of the test syndrome, receives test parity data generated by the ECC engine based on the test syndrome and a decoding status flag indicating error status of the test parity data, and determines whether the ECC engine has a defect based on comparison of the test syndrome and the test parity data and a comparison of the expected decoding status flag and the decoding status flag.

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.

Various examples described herein are directed to systems and methods for generating data values using a NAND flash array. A memory controller may read a number of memory cells at the NAND flash array using an initial read level to generate a first raw string. The memory controller may determine that a difference between a number of bits from the first raw string having a value of logical zero and a number of bits from the first raw string having a value of logical one is greater than a threshold value and read the number of memory cells using a second read level to generate a second raw string. The memory controller may determine that a difference between a number of bits from the second raw string having a value of logical zero and a number of bits from the second raw string having a value of logical one is not greater than a threshold value and applying a cryptographic function using the second raw string to generate a first PUF value.

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 write circuit for writing to a plurality of memory cells of a non-volatile data memory, including a buffer memory forming a single memory element which is configured to buffer a first data value before storing said value in the plurality of non-volatile memory cells of the non-volatile data memory. The write circuit also includes a first write line, by means of which the buffer memory is connected to a first memory cell of the plurality of memory cells, and a second write line, which is different from the first write line and by means of which the buffer memory is connected to a second memory cell of the plurality of memory cells. The write circuit further includes a control circuit configured to concurrently write the first data value in the first memory cell and a second data value which depends on the first data value into the second memory cell, wherein the second data value is complementary to the first data value or is identical to the first data value depending on a selected one of a first option or a second option by the control circuit, respectively.

Various examples described herein are directed to systems and methods for generating data values using a NAND flash array. A memory controller may read a number of memory cells at the NAND flash array using an initial read level to generate a first raw string. The memory controller may determine that a difference between a number of bits from the first raw string having a value of logical zero and a number of bits from the first raw string having a value of logical one is greater than a threshold value and read the number of memory cells using a second read level to generate a second raw string. The memory controller may determine that a difference between a number of bits from the second raw string having a value of logical zero and a number of bits from the second raw string having a value of logical one is not greater than a threshold value and applying a cryptographic function using the second raw string to generate a first PUF value.

A semiconductor apparatus including a semiconductor chip is disclosed. The semiconductor chip includes 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 are randomly formed related to a part or a whole of the modular area of the modular region. The test circuit outputs a random number generated from physical properties intrinsic to the semiconductor chip according to a specification code received from a physical-chip-identification measuring device.

A semiconductor apparatus including a semiconductor chip is disclosed. The semiconductor chip includes 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 are randomly formed related to a part or a whole of the modular area of the modular region. The test circuit outputs a random number generated from physical properties intrinsic to the semiconductor chip according to a specification code received from a physical-chip-identification measuring device.

A method for testing a memory chip including: performing an electrical die sorting (EDS) test on the memory chip; performing a package test when the EDS test is passed; performing a module test when the package test is passed; performing a mounting test when the module test is passed; and setting the memory chip to a mirroring mode through a fusing operation when the EDS test, tire package test, tire module test or the mounting test is failed.

A method for testing a memory chip including: performing an electrical die sorting (EDS) test on the memory chip; performing a package test when the EDS test is passed; performing a module test when the package test is passed; performing a mounting test when the module test is passed; and setting the memory chip to a mirroring mode through a fusing operation when the EDS test, tire package test, tire module test or the mounting test is failed.