Abstract: A memory device for improving the speed of a program operation and an operating method thereof is provided. The memory device includes a memory cell array including a plurality of memory cells, a voltage generator configured to generate voltages for one or more program operations and a verify operation performed on the plurality of memory cells, a control logic configured to perform a control operation on the plurality of memory cells so that a first program and a second program loop are performed, a second program operation being performed based on a compensation voltage level determined based on a result of the first verify operation, and a plurality of bit lines connected to the memory cell array, wherein the first verify operation includes first even sensing and second even sensing on even-numbered bit lines, and first odd sensing and second odd sensing on odd-numbered bit lines.

Abstract: A read voltage level correction method, a memory storage device, and a memory control circuit unit are provided. The method includes: using a first read voltage level as an initial read voltage level to perform a first data read operation on a first physical unit among multiple physical units to obtain a second read voltage level used to successfully read the first physical unit; recording association information between the first read voltage level and the second read voltage level in a transient look-up table; and performing a second data read operation according to a read level tracking table and the association information recorded in the transient look-up table.

Abstract: Methods, systems, and devices for operating a memory array with variable page sizes are described. The page size may be dynamically changed, and multiple rows of the memory array may be accessed in parallel to create the desired page size. A memory bank of the array may contain multiple memory sections, and each memory section may have its own set of sense components (e.g., sense amplifiers) to read or program the memory cells. Multiple memory sections may thus be accessed in parallel to create a memory page from multiple rows of memory cells. The addressing scheme may be modified based on the page size. The logic row address may identify the memory sections to be accessed in parallel. The memory sections may also be linked and accessing a row in one section may automatically access a row in a second memory section.

Abstract: A circuit for monitoring usage of an active field effect transistor (FET) includes the active FET and a reference FET, formed in a same structure as the active FET. The active FET and the reference FET both are pFET or both are nFET, and are stacked on each other at a common gate. The circuit also includes a differential current sense circuit (DCSC) and a plurality of switches for connecting terminals of the FETs to logic voltage, ground voltage, and/or the DCSC. The DCSC is configured to measure and compare currents through each of the active and reference FETs when a threshold voltage is applied to the common gate.

Abstract: A nonvolatile memory device according to the embodiment includes: a first inverter; and a second inverter cross-coupled to the first inverter, wherein the second inverter includes a pull-up transistor, a pull-down transistor, and a ferroelectric field effect transistor having gate nodes connected to each other, and a restore transistor having one electrode connected to the ferroelectric field effect transistor, and the second inverter stores data in a nonvolatile manner.

Abstract: A memory comprises a substrate, and word lines, bit lines and memory cells located on one side of the substrate. Each of the memory cells comprises a transistor comprising: a semiconductor layer comprising a source contact region, a channel region and a drain contact region connected sequentially; a primary gate electrically connected to one of the word lines; a source electrically connected to one of the bit lines and the source contact region of the semiconductor layer, respectively; a drain electrically connected to the drain contact region of the semiconductor layer; and a secondary gate electrically connected to the drain, wherein an orthographic projection of the primary gate on the substrate and an orthographic projection of the secondary gate on the substrate are at least partially overlapped with an orthographic projection of the channel region of the semiconductor layer on the substrate, respectively.

Abstract: The semiconductor memory device of the embodiment includes: a substrate; a first memory pillar extending in a first direction from the substrate, the first memory pillar including first memory cell transistors, a first selection transistor, a second selection transistor, second memory cell transistors, a third selection transistor, a fourth selection transistor, third memory cell transistors, a fifth selection transistor, a sixth selection transistor, fourth memory cell transistors, a seventh selection transistor, and an eighth selection transistor; a first select gate line; first word lines; a second select gate line; a third select gate line; second word lines; a fourth select gate line; a fifth select gate line; third word lines; a sixth select gate line; a seventh select gate line; fourth word lines; and an eighth select gate line.

Abstract: A memory device includes a memory array including a cell, and a controller coupled to the memory array. The controller is configured to control sequentially applying programming voltage pulses to the cell. A pulse width of each of the programming voltage pulses decreases as a pulse count of the programming voltage pulses increases.

Abstract: Some embodiments include apparatuses and methods of forming the apparatuses. One of the apparatuses includes a conductive region, a first data line, a second data line, a first memory cell coupled to the first data line and the conductive region, a second memory cell coupled to the second data line and the conductive region, a conductive structure, and a conductive line. The first memory cell includes a first transistor coupled to a second transistor, the first transistor including a first charge storage structure. The second memory cell includes a third transistor coupled to a fourth transistor, the third transistor including a second charge storage structure. The conductive structure is located between and electrically separated from the first and second charge storage structures. The conductive line forms a gate of each of the first, second, third, and fourth transistors.

Abstract: In accordance with an embodiment, a circuit includes: a trimmable reference current generator having a temperature dependent current output node, the trimmable reference current generator including: a proportional to absolute temperature (PTAT) current generation circuit; a first programmable current scaling circuit coupled to the PTAT current generation circuit and including a first output coupled to the temperature dependent current output node; a constant current generation circuit; a second programmable current scaling circuit coupled to the constant current generation circuit and including a first output coupled to the temperature dependent current output node; and a reference interface circuit having an input coupled to the temperature dependent current output node and an output configured to be coupled to a reference current input of a memory sense amplifier.

Abstract: A non-volatile memory device includes a control circuit configured to connect to a bit line that is connected to one or more non-volatile memory cells. The control circuit includes a first plurality of data latches connected to a first local data bus to store first program-verify pass/fail bits and a second plurality of data latches connected to a second local data bus to store second program-verify pass/fail bits for second non-volatile memory cells. The non-volatile memory device further includes a shared isolation latch and one or more interface circuits connected to the first local data bus and the second local data bus. The one or more interface circuits are configured to selectively block the first program-verify pass/fail bits from the first plurality of latches and the second program-verify pass/fail bits from the second plurality of latches according to an indicator bit stored in the shared isolation latch.

Abstract: An apparatus is provided that includes a memory die having a first memory cell, and a controller connected to the memory die. The controller is configured to apply a plurality of programming pulses to the first memory cell, apply a plurality of first verify pulses to the first memory cell, determine from the first verify pulses that the first memory cell has been programmed to a first programmed memory state, apply a single second verify pulse to the first memory cell after determining that the first memory cell has been programmed to the first programmed memory state, determine from the single second verify pulse that the first memory cell is no longer programmed to the first programmed memory state, and apply an additional programming pulse to the first memory cell.

Abstract: Methods, systems, and devices for reference voltage adjustment for word line groups are described. In some examples, one or more components of a memory system may determine a duration that data has been stored to one or more memory cells. Based on the duration, a voltage value of one or more reference voltages may be adjusted accordingly. For example, a voltage value of one or more reference voltages may be adjusted based on the duration. Moreover, the reference voltage values may be adjusted differently in response to the memory cells having stored data for a relatively longer duration, as opposed to memory cells that have stored data for a relatively shorter duration. The adjusted reference voltages may be used during a subsequent read operation. The voltage value of the one or more reference voltages may be adjusted on a word-line group by word-line group basis.

Abstract: A storage device includes a nonvolatile memory device and a memory controller. An operating method of the storage device includes sending, at the memory controller, a first read command and first offset information to the nonvolatile memory device, performing, at the nonvolatile memory device, first read operations based on the first read command and the first offset information, sending, at the nonvolatile memory device, a result of the first read operations as first data to the memory controller, sending, at the memory controller, a second read command, read voltage levels, and second offset information to the nonvolatile memory device, performing, at the nonvolatile memory device, second read operations based on the second read command, the read level information, and the second offset information, and sending, at the nonvolatile memory device, results of the second read operations as second data to the memory controller.

Abstract: Methods, systems, and devices for signal development circuitry layouts in a memory device are described. A memory device may include signal development circuitry that is positioned in multiple levels of a memory die relative to a substrate. For example, a set of first transistors used for developing access signals may be located on a first level of a memory die, and a set of second transistors used for developing the access signals may be located on a second level of the memory die. Formation of the set of first transistors and the set of second transistors may involve processing operations that are common with the formation of other transistors on a respective level, such as cell selection transistors, deck selection transistors, shunting transistors, and other transistors of the respective level.

Abstract: A nonvolatile memory device includes a plurality of bit lines that is connected with a plurality of cell strings, a common source line that is connected with the plurality of cell strings, at least one dummy bit line that is provided between the common source line and the plurality of bit lines, a control logic circuit that generates at least one dummy bit line driving signal in response to a command from an external device, and a dummy bit line driver that selectively provides a first voltage to the at least one dummy bit line in response to the dummy bit line driving signal.

Abstract: The memory device includes a controller that is configured to program the memory cells of a selected word line in a plurality of program-verify iterations. During a verify portion at least one of the program-verify iterations, the controller determines a threshold voltage of at least one memory cell relative to a first verify low voltage VL1, a second verify low voltage VL2, and a verify high voltage VH associated with a data state being programmed. The controller also maintains a count of program-verify iterations since the at least one memory cell passed a verify high voltage of a previously programmed data state or discharges a sense node through a channel including the at least one memory cell and compares a discharge time to predetermined sense times associated with the first and second verify low voltages and with the verify high voltage.

Abstract: Systems of screening memory cells of a memory include modulating bitline and/or wordline voltage. In a read operation, the wordline may be overdriven or underdriven with respect to a nominal operating voltage on the wordline. In a write operation, one or both of the bitline and wordline may be overdriven or underdriven with respect to corresponding a nominal operating voltage. Such a system has margin control circuity, which may be in the form of bitline and wordline margin controls, to modulate bitline and wordline voltages, respectively, in the memory cells of the memory array.

Abstract: Systems and methods are disclosed including a memory device and a processing device operatively coupled to the memory device. The processing device can perform operations including performing a read operation on a block of the memory device by applying a read reference voltage to a selected wordline of the block and applying a pass-through voltage having a first value to a plurality of unselected wordlines of the block; detecting a read error in response to performing the read operation; and setting the pass-through voltage to a second value, wherein the second value is greater than the first value.

Abstract: A method for performing memory access of a Flash cell of a Flash memory includes: performing a plurality of sensing operations respectively corresponding to a plurality of sensing voltages to generate a first digital value and a second digital value of the Flash cell, the second digital value representing at least one candidate threshold voltage of the Flash cell; determining a threshold voltage of the Flash cell according to whether the at least one candidate threshold voltage is high or low; determining soft information of a bit stored in the Flash cell according to the threshold voltage of the Flash cell; and using the soft information to perform soft decoding.

Abstract: A memory device including a plurality of memory cells, a peripheral circuit, and a control logic. The peripheral circuit performs a first read operation using a plurality of read voltages on selected memory cells. The control logic controls the peripheral circuit to perform a cell counting operation, adjust remaining read voltages among the plurality of read voltages based on a read offset table and a cell count which is a result of the cell counting operation, and perform a first read operation on the selected memory cell with the remaining read voltages, in the first read operation. The control logic performs a read data output operation of a second read operation performed before the first read operation and the cell counting operation corresponding to the first read operation in parallel among a plurality of successively performed read operations.

Abstract: A sense amplifier, a control method of the sense amplifier, and a memory are provided. The sense amplifier includes: a first power input terminal, a second power input terminal, a first switch transistor, a second switch transistor, a third switch transistor, a fourth switch transistor, a fifth switch transistor, a first negative-channel metal-oxide semiconductor (NMOS) transistor, a second NMOS transistor, a first positive-channel metal-oxide semiconductor (PMOS) transistor and a second PMOS transistor.

Abstract: The present disclosure describes embodiments of a device with memory and a processor. The memory is configured to store integrated circuit (IC) trim and redundancy information. The processor is configured to extract bits from the IC trim and redundancy information, perform a hashing function on the extracted bits to generate hashed bits, and in response to statistical properties of the hashed bits meeting one or more criteria, output the hashed bits. In some embodiments, the memory that stores the IC trim and redundancy information can be different from other memory used by the device for other operations (e.g., accessing user data and program data that have been written into system memory).

Abstract: An apparatus is provided that includes a plurality of word lines that include a plurality of word line zones, a plurality of non-volatile memory cells coupled to the plurality of word lines, and a control circuit coupled to the non-volatile memory cells. The control circuit is configured to determine a corresponding initial program voltage for each of the word line zones. Each corresponding initial program voltage is determined based on a number of program erase cycles.

Abstract: Numerous embodiments are disclosed for compensating for differences in the slope of the current-voltage characteristic curve among reference transistors, reference memory cells, and flash memory cells during a read operation in an analog neural memory in a deep learning artificial neural network. In one embodiment, a method comprises receiving an input voltage, multiplying the input voltage by a coefficient to generate an output voltage, applying the output voltage to a gate of a selected memory cell, performing a sense operating using the selected memory cell and a reference device to determine a value stored in the selected memory cell, wherein a slope of a current-voltage characteristic curve of the reference device and a slope of the current-voltage characteristic curve of the selected memory cell are approximately equal during the sense operation.

Abstract: The disclosure relates to a microelectromechanical apparatus including a substrate, a stationary electrode, a movable electrode, and a heater. The substrate includes an upper surface, an inner bottom surface, and an inner side surface. The inner side surface surrounds and connects with the inner bottom surface. The inner side surface and the inner bottom surface define a recess. The stationary electrode is disposed on the inner bottom surface. The movable electrode covers the recess. The movable electrode, the inner bottom surface, and the inner side surface define a hermetic chamber. The heater is disposed on the movable electrode and located above the hermetic chamber.

Abstract: Disclosed is a reconfigurable complementary metal oxide semiconductor (CMOS) device with multiple operating modes (e.g., frequency multiplication mode, etc.). The device includes an N-type field effect transistor (NFET) and a P-type field effect transistor (PFET), which are threshold voltage-programmable, which are connected in parallel, and which have electrically connected gates. The threshold voltages of the NFET and PFET can be concurrently programmed and the operating mode of the device can be set depending upon the specific combination of threshold voltages achieved in the NFET and PFET. Optionally, the threshold voltages of the NFET and PFET can be concurrently reprogrammed to switch the operating mode. Such a device is relatively small and achieves frequency multiplication and other functions with minimal power consumption. Also disclosed are methods for forming the device and for reconfiguring the device (i.e., for concurrently programming the NFET and PFET to set or switch operating modes).

Abstract: A data storage device and method for providing a temperature-driven variable storage capacity point are provided. In one embodiment, the data storage device determines that a temperature of the memory exceeds a threshold that triggers a decrease in performance of the data storage device; informs a host in communication with the data storage device that the temperature of the memory exceeds the threshold; receives an instruction from the host to avoid the decrease in the performance of the data storage device by reducing an effective capacity of the memory for an amount of time; and reduces the effective capacity of the memory for at least part of the amount of time by foregoing a background operation that maintains or increases the effective capacity of the memory. Other embodiments are possible, and each of the embodiments can be used alone or together in combination.

Abstract: A plurality of memory units residing in a first location of a memory device is identified, wherein the first location of the memory device corresponds to a first layer of a plurality of layers of the memory device. It is determined whether a write disturb capability associated with the first location of the memory device satisfies a threshold criterion. Responsive to determining that the write disturb capability associated with the first location of the memory device satisfies the threshold criterion, a plurality of logical addresses associated with the plurality of memory units is remapped to a second location of the memory device, wherein the second location of the memory device corresponds to a second layer of the plurality of layers of the memory device, and wherein a write disturb capability associated with the second location of the memory device does not satisfy the threshold criterion.

Abstract: For a non-volatile memory system with a multi-plane memory die having a large block size, to be able to more readily accommodate zone-based host data using zones that are of a smaller size that the block size on the memory, the memory system assigns data from different zones to different subsets of the planes of a common memory die. The memory system is configured to accumulate the data from the different zones into different write queues and then assemble the data from the different write zones into pages or partial pages of data that can be simultaneously programmed into memory cells connected to different word lines that are in different sub-blocks of different blocks in the corresponding assigned planes of the die.

Abstract: A semiconductor apparatus implementing a high speed data output and compensating a resetting of a latch circuit is provided. A readout method of a NAND type flash memory includes: a pre-charging step performing a pre-charging on a bit line and a NAND string connected to the bit line through a sense node (SNS); a resetting step performing a resetting on the latch circuit after the pre-charging; and a discharging step performing a discharging on the NAND string after the resetting.

Abstract: A data device with a small circuit area and reduced power consumption is used. The data processing device includes a NAND memory portion and a controller. The memory portion includes a first string and a second string in different blocks. The first string includes a first memory cell, and the second string includes a second memory cell. On reception of first data and a signal including an instruction to write the first data, the controller writes the first data to the first memory cell. Then, the controller reads the first data from the first memory cell and writes the first data to the second memory cell.

Abstract: A semiconductor memory device includes a substrate, first and second P-type well regions on the substrate, an N-type well region on the substrate and sandwiched between the first and second P-type well regions, a first peripheral circuit on a region of the first P-type well region adjacent to the N-type well region and supplied with a reference voltage via a first wiring, and a second peripheral circuit on a region of the second P-type well region adjacent to the N-type well region and supplied with a reference voltage via a second wiring.

Abstract: A semiconductor memory device includes word lines, first and second select gate lines, first and second semiconductor columns, first and second bit lines, and first and second transistors. The word lines are arranged in a first direction. The first and second select gate lines extend in a second direction and overlap with the word lines viewed from the first direction. The first and second select gate lines are arranged in the second direction. The first semiconductor column is opposed to the word lines and the first select gate line. The second semiconductor column is opposed to the word lines and the second select gate line. The first and second bit lines extend in a third direction and overlap with the first and second semiconductor columns viewed from the first direction. The first and second transistors are electrically connected to the first and second select gate lines.

Abstract: A signal generator includes a first amplifier for outputting an amplified voltage in response to a reference voltage and a feedback voltage, a divider circuit for dividing the amplified voltage to generate a divided voltage and the feedback voltage, and a buffer group for outputting a common sensing signal in response to the amplified voltage and outputting a sensing signal in response to the divided voltage, and a memory device including the signal generator.

Abstract: According to one embodiment, a memory device includes: a plurality of memory cells stacked in a first direction orthogonal to a substrate and each including a memory element having at least three resistance states and a selector coupled in parallel to the memory element; a bit line electrically coupled to the memory cells and extending in a second direction intersecting the first direction; and a sense amplifier configured to compare a voltage of the bit line with a plurality of reference voltages and sense data stored in the memory cells.

Abstract: Read operations can be performed to read data stored at a data block. Parameters reflective of a separation between a pair of programming distributions associated with the data block can be determined based on the plurality of read operations. A read request to read the data stored at the data block can be received. In response to receiving the read request, a read operation can be performed to read the data stored at the data block based on the parameters that are reflective of the separation between the pair of programming distributions associated with the data block.

Abstract: Embodiments relate to improving the biasing of active electronic components such as, for example, sense amplifiers. Embodiments include an adjustable bias signal generator that receives a reference signal as an input and generates a corresponding bias signal as an output. The adjustable bias signal generator may comprise a voltage driver and capacitor divider circuitry. In some embodiments, the capacitor divider circuitry is configurable by selecting specific capacitor dividers using a digital code. In other embodiments, the voltage driver is adjustable by applying different trim settings to tune the output of the voltage driver. The voltage driver may be temperature compensated by multiplexing different trim settings that correspond to different temperatures.

Abstract: According to an embodiment, a memory controller obtains first data in a first page using a first voltage, obtains a first shift amount based on a first and second number. The first and second numbers represent numbers of bits each of which has different values in a first and second manner between the first data and first expected data. The controller obtains second data in the second page using a second voltage and a second shift amount, and obtains a third shift amount based on a third and fourth number, the third and fourth numbers respectively represent numbers of bits each of which has different values in the first and second manner between the second data and second expected data.

Abstract: A read operation is performed on a memory device in accordance with a pass-through voltage setting that defines a pass-through voltage applied to one or more cells of the memory device during read operations. A number of zero bits read from the memory device based on the read operation are counted and compared with a threshold value. Based on the number of zero bits exceeding the threshold value, the pass-through voltage is increased by adjusting the pass-through voltage setting.

Abstract: Methods, systems, and devices for memory management associated with charge leakage in a memory device are described. A memory device may identify a charge leakage associated with one or more memory cells or access lines, and may determine whether to invert a logic state stored by a memory cell or a set of memory cells to improve the likelihood that the memory cells are read properly in the presence of charge leakage. In some examples, the memory device may also store an indication that the complement of the detected logic state was written, such as a bit flip indication, which may correspond to one memory cell or a set of memory cells.

Abstract: A memory array includes a plurality of column segments, each column segment including a plurality of columns of memory cells, a plurality of sense amplifiers selectively coupled to each column of the plurality of columns of a corresponding column segment, pluralities of first and second reference cells, and a reference current circuit. The reference current circuit generates a reference current based on a first current generated by a first reference cell programmed to a low logical value and a second current generated by a second reference cell programmed to a high logical value. Each sense amplifier generates a mirror current based on the reference current, and a logical value based on a comparison of the mirror current to a cell current received from a memory cell of a column of the plurality of columns of the corresponding column segment.

Abstract: Some embodiments include apparatuses and methods of forming the apparatuses. One of the apparatuses includes a conductive region, a first data line, a second data line, a first memory cell coupled to the first data line and the conductive region, a second memory cell coupled to the second data line and the conductive region, a conductive structure, and a conductive line. The first memory cell includes a first transistor coupled to a second transistor, the first transistor including a first charge storage structure. The second memory cell includes a third transistor coupled to a fourth transistor, the third transistor including a second charge storage structure. The conductive structure is located between and electrically separated from the first and second charge storage structures. The conductive line forms a gate of each of the first, second, third, and fourth transistors.

Abstract: The invention relates to a method, an apparatus and a computer program product for reading data from multiple flash dies. The method is performed by a processing unit when loading and executing program code to include: issuing a read instruction to a flash interface to drive the flash interface to activate a data read operation for reading data from a location in a die; calculating an output time point corresponding to the read instruction; and issuing a random out instruction corresponding to the read instruction to the flash interface to drive the flash interface to store the data in a random access memory (RAM) when a current time reaches to, or is later than the output time point.

Abstract: Disclosed herein is a method for designing a semiconductor device, the method including: assigning a plurality of wiring tracks including first and second tracks; connecting a first data I/O circuit to a first data node of a first circuit by a first signal bus arranged on the first wiring track; connecting a second data I/O circuit to a second data node of the first circuit by a second signal bus arranged on the second wiring track when a first design mode is selected; and connecting the first data I/O circuit to a second circuit by a second signal bus arranged on the second wiring track when a second design mode is selected.

Abstract: A method for operating a three-dimensional (3D) memory device includes performing a first read operation for sensing a first memory cell of a first transistor string, and performing a subsequent second read operation for sensing a second memory cell of a second transistor string. Performing the first read operation includes applying a first bit line voltage to a first bit line, and maintaining the first bit line basically undischarged after data state of the first memory cell is detected.

Abstract: A processing device of a memory sub-system is configured to identify a read level of a plurality of read levels associated with a voltage bin of a plurality of voltage bins of a memory device; assign a first threshold voltage offset to the read level of the voltage bin; assign a second threshold voltage offset to the read level of the voltage bin; perform, on block associated with the read level, a first operation of a first operation type using the first threshold voltage offset; and perform, on the blocks associated with the read level, a second operation of a second operation type using the second threshold voltage offset.

Abstract: Some embodiments include apparatuses and methods of forming the apparatuses. One of the apparatuses includes a memory cell, first, second, and third data lines, and first and second access lines. Each of the first, second, and third data lines includes a length extending in a first direction. Each of the first and second access lines includes a length extending in a second direction. The memory cell includes a first transistor including a charge storage structure, and a first channel region electrically separated from the charge storage structure, and a second transistor including a second channel region electrically coupled to the charge storage structure. The first data line is electrically coupled to the first channel region. The second data line is electrically coupled to the first channel region. The third data line is electrically coupled to the second channel region, the second channel region being between the charge storage structure and the third data line.

Abstract: A system includes a memory device including a memory array including a plurality of wordline groups and control logic, operatively coupled with the memory array, to perform operation including causing a first erase verify to be performed sequentially with respect to each wordline group of the plurality of wordline groups, identifying a set of failing wordline groups determined to have failed the first erase verify, and causing a second erase verify to be performed sequentially with respect to each wordline group of the set of failing wordline groups.

Abstract: A semiconductor memory device and a memory system are provided. The semiconductor memory device includes a fingerprint read signal generator configured to generate a fingerprint read signal in response to a refresh counting control signal, a memory cell array comprising a plurality of sub memory cell array blocks, a fingerprint output unit configured to receive data output from memory cells connected to one selected among a plurality of word lines and one selected among a plurality of bit lines of one among the plurality of sub memory cell array blocks in response to the fingerprint read signal to generate fingerprint data, and a pseudorandom number generator configured to perform a linear feedback shifting operation in response to an active command to generate sequence data, receive the fingerprint data in response to the fingerprint read signal, and generate the sequence data based on the fingerprint data.