A physically unclonable function (PUF) device includes first and second inverters, each of which includes a common gate node and a common drain node. The common drain node of the first inverter is electrically connected to the common gate node of the second inverter. The PUF device also includes a common output node, a first resistive memory device (RMD) electrically connected to the common drain node of the first inverter and the common output node, and a second RMD electrically connected to the common drain node of the second inverter and the common output node.

A non-volatile semiconductor memory device includes a memory array 20, including a plurality of memory elements; a selection part, selecting the memory elements of the memory array based on address data; a mode selection part 30, selecting any one of a RAM mode and a flash mode, where the RAM mode is a mode adapted to overwrite data of the memory element according to writing data, and the flash mode is a mode adapted to overwrite data of the memory element when the writing data is a first value and prohibit overwrite when the writing data is a second value; and a write control part, writing the writing data to the selected memory element according to the RAM mode or the flash mode selected by the mode selection part 30.

Stochastic or near-stochastic physical characteristics of resistive switching devices are utilized for generating data distinct to those resistive switching devices. The distinct data can be utilized for applications related to electronic identification. As one example, data generated from physical characteristics of resistive switching devices on a semiconductor chip can be utilized to form a distinct identifier sequence for that semiconductor chip, utilized for verification applications for communications with the semiconductor chip or utilized for generating cryptographic keys or the like for cryptographic applications.

Memory devices, systems including memory devices, and methods of operating memory devices are described, in which security measures may be implemented to control access to a fuse array (or other secure features) of the memory devices based on a secure access key. In some cases, a customer may define and store a user-defined access key in the fuse array. In other cases, a manufacturer of the memory device may define a manufacturer-defined access key (e.g., an access key based on fuse identification (FID), a secret access key), where a host device coupled with the memory device may obtain the manufacturer-defined access key according to certain protocols. The memory device may compare an access key included in a command directed to the memory device with either the user-defined access key or the manufacturer-defined access key to determine whether to permit or prohibit execution of the command based on the comparison.

A non-volatile memory device includes a plurality of memory cells arranged in a matrix, a plurality of word lines extended in a row direction, and a plurality of bit lines extended in a column direction. Each of the memory cells is coupled to one of the word lines and one of the bit lines. The memory device further includes a word-line control circuit coupled to and configured to control the word lines, a first bit-line control circuit configured to control the bit lines and sense the memory cells in a digital mode, and a second bit-line control circuit configured to bias the bit lines and sense the memory cells in an analog mode. The first bit-line control circuit is coupled to a first end of each of the bit lines. The second bit-line control circuit is coupled to a second end of each of the bit lines.

Provided are memory devices and memory systems. The memory device includes a memory cell array in a first semiconductor layer and including word lines stacked in a first direction, and channel structures passing through the word lines in the first direction; a control logic circuit in a second semiconductor layer located below the first semiconductor layer in the first direction; and a physical unclonable function (PUF) circuit including a plurality of through electrodes passing through the first semiconductor layer and the second semiconductor layer, and configured to generate PUF data according to resistance values of the plurality of through electrodes, and generate the PUF data based on a node voltage between through electrodes connected in series, among the plurality of through electrodes.

Memory devices, systems including memory devices, and methods of operating memory devices are described, in which security measures may be implemented to control access to a fuse array (or other secure features) of the memory devices based on a secure access key. In some cases, a customer may define and store a user-defined access key in the fuse array. In other cases, a manufacturer of the memory device may define a manufacturer-defined access key (e.g., an access key based on fuse identification (FID), a secret access key), where a host device coupled with the memory device may obtain the manufacturer-defined access key according to certain protocols. The memory device may compare an access key included in a command directed to the memory device with either the user-defined access key or the manufacturer-defined access key to determine whether to permit or prohibit execution of the command based on the comparison.

A read-only memory cell array includes a first storage state memory cell and a second storage state memory cell. The first storage state memory cell includes a first transistor and a second transistor. The first transistor is connected to a source line and a word line. The second transistor is connected to the first transistor and a first bit line. The second storage state memory cell includes a third transistor and a fourth transistor. The third transistor is connected to the source line and the word line. The fourth transistor is connected to the third transistor and a second bit line. A gate terminal of the fourth transistor is connected to a gate terminal of the third transistor.

A semiconductor device includes a logic circuit, a memory, and a storage device. The storage device has a first special information storage region into which special information is written before a solder reflow process, a second special information storage region into which special information for updating is written after the solder reflow process, and a data storage region. The first special information storage region is constituted by a memory cell having a high reflow resistance and in which data is retained even after the solder reflow process. The second special information storage region and the data storage region are constituted by memory cells having a low reflow resistance and in which data may not be retained during the solder reflow process.

A technique relates to biasing, using a control system, a crossbar array of resistive processing units (RPUs) under a midrange condition, the midrange condition causing resistances of the RPUs to result in a random output of low values and high values in about equal proportions. The control system reinforces the low values and the high values of the random output by setting the resistances of the RPUs to a state that forces the low values and the high values having resulted from the midrange condition. Reinforcing the low values and the high values makes the random output permanent even when the crossbar array of the RPUs is not biased under the midrange condition. The control system records a sequence of the low values and the high values of the random output responsive to reinforcing the low values and the high values of the random output.