Abstract: A sense amplifier includes a first pair of transistors having gate terminals respectively coupled to a first input terminal for receiving a first input signal and to a second input terminal for receiving a second input signal, source terminals coupled to a first power supply terminal, and drain terminals. The sense amplifier also includes a second pair of transistors having gate terminals coupled to a clock terminal, source terminals respectively coupled to the drain terminals of the first pair of transistors, and drain terminals. The sense amplifier also includes a third pair of transistors having gate terminals coupled to the clock terminal, drain terminals respectively coupled to the drain terminals of the second pair of transistors, and source terminals coupled to a second power supply terminal. In addition, the sense amplifier includes an output circuit coupled to the drain terminals of the second pair of transistors and having an output terminal.

Abstract: A keeper device is used in a hybrid loop unrolled DFE circuit to selectively output signals from equalizers corresponding to a specific possibility of the values of the previous bit (e.g., logical high or logical low) when DFE technique is not used. Those equalizers corresponding to possibilities other than the specific possibility of the values of the previous bit are disabled in the hybrid loop unrolled DFE circuit. As such, the hybrid loop unrolled DFE circuit saves power when the DFE technique is not used since only a portion of the total equalizers in the hybrid loop unrolled DFE circuit are powered.

Abstract: The material layer stack includes first and second magnetic tunnel junctions and a first top electrode formed on a top face of the stack. A shoulder is formed on a lateral face of the stack and divides the stack into a lower portion and an upper portion. A tunnel barrier of the first magnetic tunnel junction is comprised by the lower stack portion and a tunnel barrier of the second magnetic tunnel junction by the upper stack portion. A second top electrode is formed on the shoulder. Each magnetic tunnel junction is adapted to store a bit as a reconfigurable magnetoresistance of its magnetic electrodes. Preferably, a bottom face of the stack is connected to a conductor supporting current induced magnetic polarization switching for the first magnetic tunnel junction by spin-orbit torque. Magnetic polarization switching for the second magnetic tunnel junction is preferably achieved by spin-transfer torque.

Abstract: A memory chip may include: a plurality of memory banks; a data storage configured to store access information indicative of access operations for one or more segments of the plurality of memory banks; and a refresh controller configured to perform a refresh operation of the one or more segments based, at least in part, on the stored access information.

Abstract: A current operating characteristic value of a unit of the memory device is identified. An operating characteristic threshold value is identified from a set of operating characteristic thresholds, where the current operating characteristic value satisfies an operating characteristic threshold criterion that is based on the operating characteristic threshold value. A set of write-to-read (W2R) delay time thresholds that corresponds to the operating characteristic threshold value is identified from a plurality of sets of W2R delay time thresholds. Each of the W2R delay time thresholds in the set is associated with a corresponding read voltage level. A W2R delay time threshold associated with a W2R delay time threshold criterion is identified from the set of W2R delay time thresholds, where the W2R threshold criterion is satisfied by a current W2R delay time of the memory sub-system. A read voltage level associated with the identified W2R delay time threshold is identified.

Abstract: A system includes a memory array with memory cells and a processing device coupled thereto. The processing device performs program targeting operations that include to: determine a set of difference error counts corresponding to programming distributions of the memory array; identify, based on a comparison of the set of difference error counts, valley margins corresponding to the programming distributions; select, based on values of the valley margins, a program targeting rule from a set of rules; perform, based on the program targeting rule, a program targeting operation to adjust a voltage level associated with an erase distribution of the memory array; determine a bit error rate (BER) of the memory array; in response to the BER satisfying a BER control value, reduce the voltage level by a voltage step; and in response to the BER not satisfying the BER control value, increase the voltage level by the voltage step.

Abstract: In an embodiment an electronic device includes a first MOS-type transistor and a second MOS-type transistor connected as current mirrors, wherein the first transistor is diode connected and a first circuit configured to provide a first current equal to a first gate current of the first transistor multiplied by a size ratio of the first and second transistors.

Abstract: Aspects of the invention include a first pull-down device and a second pull-down device, wherein a first drain terminal is connected to a second source terminal, and wherein a first gate terminal is connected to a true read local bitline, wherein a second drain terminal is connected to a compliment read local bit line, and wherein a second gate terminal is connected to a true write global bitline, a third pull-down device and a fourth pull-down device, wherein a third source terminal is connected to the voltage supply, wherein a third drain terminal is connected to a fourth source terminal, and wherein a third gate terminal is connected to the compliment read local bitline, and wherein a fourth drain terminal is connected to the true read local bitline, and wherein a fourth gate terminal is connected to a compliment write global bit line.

Abstract: The present disclosure relates to the field of semiconductor circuit design, and in particular to a readout circuit layout structure and a method of reading data. The readout circuit layout structure includes: a first readout circuit structure and a second readout circuit structure having identical structures, wherein the first readout circuit structure and the second readout circuit structure each include: a first isolation module, configured to be turned on according to a first isolation signal, electrically connect a bit line and a first readout bit line, and electrically connect a complementary bit line and a first complementary readout bit line; a second isolation module, configured to be turned on according to a second isolation signal, electrically connect the first readout bit line and a second readout bit line, and electrically connect the first complementary readout bit line and a second complementary readout bit line.

Abstract: A physically unclonable function (PUF) includes a bit cell that includes a latch and a switch to selectively couple the latch to a supply voltage node. A first transmission gate couples a first bit line to a first internal node of the latch and a second transmission gate couples a second bit line to a second internal node of the latch. A digital to analog converter (DAC) circuit is selectively coupled to the first internal node through the first bit line and the first transmission gate and to the second internal node through the second bit line and the second transmission gate, to thereby precharge the latch before the first bit cell is read. The latch regenerates responsive to the switch being closed to connect the latch to the supply voltage node. The first and second bit lines are used to read the regenerated value of the latch.

Abstract: A memory access method and a computer system are provided. According to the memory access method, whether to flip the to-be-stored data for storage may be determined based on quantities of “1” and “0” in data to be written into a dynamic random access memory (DRAM) and a storage mode of the DRAM, to reduce a quantity of storage cells with high electric charges in the DRAM, thereby reducing a data error probability.

Abstract: The present disclosure includes apparatuses and methods for bank to bank data transfer. An example apparatus includes a plurality of banks of memory cells, an internal bus configured to transfer data between the plurality of banks and an external bus interface, and a bank-to-bank transfer bus configured to transfer data between the plurality of banks.

Abstract: There is provided herein circuitry and methods for applications including touch detection and, in embodiments, low rate communication such as for secure device authentication. The method uses a circuit having a first device having a first pair of unconnected plates and an edge source coupled therebetween. The circuit further comprises a second device having a second pair of respective unconnected plates and a charge sensor coupled therebetween. The method for touch detection comprises applying at least one differential edge between the first pair of unconnected plates using the edge source and detecting touch by coherently (i.e. in time) sensing an imbalance in a near field channel formed between the plates and an output signal of the charge sensor. The present method/circuit has various applications including for touch detection in fencing and secure device authentication employing both touch detection and bidirectional cryptographic communication between key and secure devices.

Abstract: Electrically conductive line side-by-side running distance equalization and related apparatuses and systems. An apparatus includes a first sense amplifier including a first pull-up sense amplifier, a first pull-down sense amplifier, and a first pair of lines connecting the first pull-up sense amplifier to the first pull-down sense amplifier. The apparatus also includes a second sense amplifier adjacent to the first sense amplifier. The second sense amplifier includes a second pull-up sense amplifier, a second pull-down sense amplifier, and a second pair of lines connecting the second pull-up sense amplifier to the second pull-down sense amplifier. Parallel running distances between lines of the first pair of lines and the second pair of lines are equalized by a wiring twist of at least one of the first pair of lines or the second pair of lines in a region of the first pull-up sense amplifier and the second pull-up sense amplifier.

Abstract: An integrated circuit may include an amplifier circuit configured to receive a pull-up voltage in response to a pull-up enable signal, receive a pull-down voltage in response to a pull-down enable signal, and amplify a voltage difference between a first line and a second line through the pull-up and pull-down voltages; a first delay path configured to generate the pull-down enable signal by delaying an input signal; and a second delay path configured to generate the pull-up enable signal by delaying the input signal, wherein a change in a delay of the first delay path due to variation of a power supply voltage is smaller than a change in a delay of the second delay path due to the variation.

Abstract: A sense amplifier (SA) includes a semiconductor substrate having a source/drain (S/D) diffusion region; a pair of SA sensing devices both disposed in the S/D diffusion region; an SA enabling device disposed in the same S/D diffusion region as where the pair of SA sensing devices are disposed in; and a sense amplifier enabling signal (SAE) line for carrying an SAE signal, for turning on the SA enabling device to discharge one of the pair of SA sensing devices during a data read from the sense amplifier, wherein the SA enabling device is arranged to provide buffer protection for source/drain terminals of the pair of SA sensing devices.

Abstract: The present disclosure relates to a structure including a first delay path circuit which is configured to receive an input signal and is connected to a complement transistor of a twin cell transistor pair through a complement bitline signal, a second delay path circuit which is configured to receive the input signal and is connected to a true transistor of the twin cell transistor pair through a true bitline signal, and a logic circuit which is configured to receive a first output of the first delay path circuit and a second output of the second delay path circuit and output a data output signal.

Abstract: In the present disclosure, it has been appreciated that memory structures, such as static random access memory (SRAM) structures, have feature densities that are extremely high. While this is beneficial in allowing the memory structures to store large amounts of data in a small chip footprint, it is potentially detrimental in that it makes the memory structures more susceptible to leakage current than the other areas of the chip. Accordingly, the present disclosure provides pseudo memory structures which are similar in terms of layout spacing to actual memory structures. However, rather than being used as actual memory structures that store data during operation, these pseudo memory structures are used to characterize leakage current in the design of the IC and/or to characterize the fabrication process used to manufacture the IC.

Abstract: The present disclosure includes apparatuses and methods related to data movement operations in non-volatile memory. An example apparatus can comprise an array of non-volatile memory cells including a plurality of sections each with a plurality of rows and a controller configured to move data stored in a first portion of the array from a first row of a first section to a second row of the first section and move data stored in a second portion of the array from a second section to the first to create an open row in the second section in response to data from a particular number of portions of memory cells in the first section being moved within the first section.

Abstract: Apparatuses for receiving an input signal in a semiconductor device are described. An example apparatus includes: a first amplifier that provides first and second intermediate voltages responsive to first and second input voltages; first and second voltage terminals; a circuit node; a first transistor coupled between the first voltage terminal and the circuit node and is turned on responsive to at least one of the first and second intermediate voltages; a second amplifier including first and second inverters, at least one of the first and second inverters being coupled between the circuit node and the second voltage terminal; and first and second output nodes, the first output node being coupled to an input node of the first inverter and an output node of the second inverter, and the second output node being coupled to an output node of the first inverter and an input node of the second inverter.

Abstract: A memory device includes a first memory cell array connected to a first internal data line; a second memory cell array connected to a second internal data line; and a line swap circuit configured to connect the first and second internal data lines with first and second external data lines based on an externally received driving signal. The line swap circuit is configured such that, when the driving signal has a first logic level, the line swap circuit connects the first and second internal data lines with the first and second external data lines, respectively, and when the driving signal has a second, different logic level, the line swap circuit swaps the first and second external data lines so that the first internal data line is connected to the second external data line and the second internal data line is connected to the first external data line.

Abstract: A semiconductor memory device includes a memory cell, a bit line connected to the memory cell, and a sense amplifier. The sense amplifier is connected to the bit line, receives a first control signal, and detects and amplifies a bit line signal of the bit line. The sense amplifier includes a precharge device that is turned on or turned off based on a read control signal, and a transistor output unit that outputs an output voltage based on the bit line signal when the precharge device is turned off.

Abstract: Some embodiments include apparatus and methods using a first diffusion region, a second diffusion region, a third diffusion region, and a fourth diffusion region; a first channel region located between a portion of the first diffusion region and a portion of the third diffusion region; a second channel region located between the portion of the third diffusion region and a portion of the second diffusion region; a third channel region located between the portion of the second diffusion region and a portion of the fourth diffusion region; and a gate located over the first, second, and third channel regions. The first and second diffusion regions are located on a first side of the gate. The third and fourth diffusion regions are located on a second side of the gate opposite from the first side.

Abstract: An embodiment relates to a sense amplifier driving device for stabilizing bit line precharge power when a post-overdriving operation is performed. The sense amplifier driving device includes a power driving unit configured to supply a first pull-up voltage and a pull-down voltage to a pull-up power line and a pull-down power line during a post-overdriving period and a driving signal generation unit configured to generate a pull-up driving signal and a pull-down driving signal activated during the post-overdriving period in order to control the driving of the power driving unit. The driving signal generation unit controls a point of time at which the pull-down driving signal shifts in response to a post-overdriving enable signal.

Abstract: A semiconductor device includes a voltage supply unit suitable for providing a first voltage as a source voltage during a standby mode, and a second voltage as the source voltage during an active mode, and a precharge unit suitable for precharging a pair of input/output lines with the source voltage during the standby mode and the active mode.

Abstract: A memory includes a first and second cell storing first data and second or reference-data. A first and second bit-lines connected to the first and second cells respectively correspond to a first and second sense-nodes. A first transfer-gate is inserted/connected between the first bit-line and the first sense-node. A second transfer-gate is inserted/connected between the second bit-line and the second sense-node. A sense-amplifier is inserted or connected between the first and second sense-nodes. A preamplifier includes a first and second common-transistors. The first common-transistor applies a first power-supply voltage to either the first or the second sense-node according to the first and second data or according to the first and reference-data during a data-read-operation. The second common-transistor applies a second power-supply voltage to the other sense-node out of the first and second sense-nodes according to the first and second data or according to the first and reference data.

Abstract: A memory system includes first memory cells and second memory cells. Each of the first memory cells includes first and second pass gates including NMOS transistors. Each of the second memory cells include first and second pass gates including PMOS transistors. The first memory cells are pre-charged by one polarity of a voltage supply. The second memory cells are pre-charged by an opposite polarity of the voltage supply.

Abstract: In a conventional DRAM, a decrease in the capacitance of a capacitor causes an error in reading data. A plurality of memory blocks MB is connected to one bit line BL_m. Each memory block MB includes a sub bit line SBL, a plurality of memory cells, and a precharge transistor. The drain of a transistor of the memory cell is connected one of the bit line BL_m and the sub bit line SBL, whereas a capacitor of the memory cell is connected to the other one of the bit line BL_m and the sub bit line SBL. The capacitance of the sub bit line SBL is sufficiently low; thus, a potential change due to electric charges of the capacitor of the memory cell can be amplified by an amplifier circuit AMP without an error and the amplified signal can be output to the bit line.

Abstract: A pre-charging method applied in DRAM which includes steps of: enabling wordlines in an active array and an reference array; disabling the wordlines in the active array; equilibrating digital lines in the active array and the reference array to half of a power supply voltage; storing the half of the power supply voltage in reference cells of the reference array; disabling the wordlines in the reference array; pre-charging the digital lines in the active array and the reference array to the power supply voltage; and enabling the wordlines in the active array and the reference array at the same time.

Abstract: A data processing method, a data processing system, and relevant devices are provided, which are used to reduce system power consumption. The method in embodiments of the present invention includes: performing sampling on an analog signal to obtain an analog sample value; performing analog-to-digital conversion on the analog sample value to obtain a digital signal; dividing bits forming the digital signal into at least two bit groups; and turning off output of bits in at least one bit group if a preset turnoff condition is satisfied. A data processing system and relevant devices are further provided.

Abstract: In this flash memory, after first and second nodes are precharged to a power supply voltage, a sense amplifier is activated, and signals appearing at the first and second nodes are held in a register. With output signals of the register, a transistor is rendered conductive, so that a constant current source for offset compensation is connected to the first or second node. Accordingly, the offset voltage of the sense amplifier can be compensated for with a simple configuration.

Abstract: A semiconductor memory device includes a bit line sense amplification unit configured to sense/amplify data loaded on a bit line, and a driving control unit configured to supply a power line of the bit line sense amplification unit with an overdriving voltage in an overdriving period and supply an internal voltage line with a voltage of the power line of the bit line sense amplification unit in a discharge driving period.

Abstract: A sense amplifier comprises a cross coupled pair of inverters, a first transistor, a second transistor, and a capacitive device. The cross coupled pair of inverters includes a first end, a second end, and a third end. The first end is configured to receive a first supply voltage. The second end is coupled with a first terminal of the capacitive device and a first terminal of the first transistor. The third end is coupled with a second terminal of the capacitive device and a first terminal of the second transistor. A second terminal of the first transistor and a second terminal of the second transistor are coupled together and are configured to receive a first control signal. A third terminal of the first transistor and a third terminal of the second transistor are coupled together and are configured to receive a second supply voltage different from the first supply voltage.

Abstract: Embodiments of a memory are disclosed that may reduce the likelihood of a miss-read while reading a weak data storage cell. The memory may include a number of data storage cells, a column multiplexer, a first sense amplifier and a second sense amplifier, and an output circuit. The gain level of the first sense amplifier may be higher than the gain level of the second sense amplifier. The output circuit may include a multiplexer and the multiplexer may be operable to controllably select one of the outputs of the first and second sense amplifiers and pass the value of the selected sense amplifier. The output circuit may include a node that couples the outputs of the first and second sense amplifiers and the outputs of the first and second sense amplifiers may be able to be set to a high impedance state.

Abstract: A sense amplifier circuit of a nonvolatile semiconductor memory device is provided. The sense amplifier circuit includes a reference voltage generator, a sensing voltage generator and a comparator. The sensing voltage generator outputs a sensing voltage to a sensing node depending on a current flowing through a data line. A load transistor supplying a current to the data line is directly connected to a clamping node. The load transistor is included in a current mirror circuit. In a read operation, a low voltage drive operation is performed and a sensing speed and power consumption are properly controlled.

Abstract: A semiconductor memory device includes a memory array including a plurality of element blocks; the plurality of element blocks including end-portion element blocks arranged at an end portion of the memory array, and at least one dummy block disposed adjacent to the end-portion element blocks, the at least one dummy block being not in practical use. A layout pattern of the at least one dummy block is configured to correspond to only a portion of a layout pattern of the plurality of element blocks.

Abstract: A semiconductor memory device according to an embodiment includes a control circuit configured to apply a first voltage to a selected first line, apply a second voltage to a selected second line, and apply a third voltage and a fourth voltage to a non-selected first line and a non-selected second line in a setting operation, respectively. The control circuit includes a detection circuit configured to detect a transition of a resistance state of a selected memory cell using a reference voltage. The control circuit is configured to execute a read operation in which the control circuit applies the third voltage to the selected first line and the non-selected first line, applies the second voltage to the selected second line, and applies the fourth voltage to the non-selected second line, and set the reference voltage based on a voltage value of the selected second line.

Abstract: A nonvolatile memory apparatus includes a read/write control unit and a voltage generation unit and the memory cell. The read/write control circuit is configured to supply a bias voltage in response to a read control signal, a write control signal and data. The voltage generation unit is configured to compare a level of the bias voltage with a voltage level of a sensing node and drive the sensing node at voltage having a constant level based on a result of the comparison. The memory cell coupled with the sensing node and configured to receive the voltage having the constant level.

Abstract: An embodiment of a method for automated test pattern generation (ATPG), a system for ATPG, and a memory configured for ATPG. For example, an embodiment of a memory includes a first test memory cell, a data-storage memory cell, and a test circuit configured to enable the test cell and to disable the data-storage cell during a test mode.

Abstract: A sense amplifier is configured to sense a current from a selected bit cell of a non-volatile memory array and compare the sensed current to a reference current to determine a logic state stored in the bit cell. A controller is configured to perform a program/erase operation on at least a portion of the memory array to change a logic state of at least one bit cell of the portion of the memory array; determine a number of program/erase pulses applied to the at least one bit cell during the program/erase operation to achieve the change in logic state; and when the number of program/erase pulses exceeds a pulse count threshold, adjust the reference current of the sense amplifier for a subsequent program/erase operation.

Abstract: A static random-access memory (SRAM) module includes a column select (RSEL) driver coupled to an input/output (I/O) circuit by an RSEL line. The I/O circuit is configured to read bit line signals from a bit cell within the SRAM module. During a read operation, the RSEL driver pulls the RSEL line to zero in order to cause p-type metal-oxide-semiconductors (PMOSs) within the I/O circuit to sample the bit line signals output by the bit cell. In response, an aggressor driver drives the RSEL line to a negative voltage, thereby reducing the resistance of the PMOSs within the I/O circuit.

Abstract: A memory comprises a memory cell, a sense amplifier, and a control unit. The memory cell stores a first bit and a second bit. The sense amplifier senses a first cell current and a second cell current corresponding to the first and the second bits respectively with a voltage applying on the memory cell. The control unit determines a digital state of the first bit by comparing a first reference current with the first cell current or by comparing a reference data with a first delta current between the first cell current and the second cell current.

Abstract: A memory device that includes a sample and hold circuit coupled to a bit line. The sample and hold circuit stores a target threshold voltage for a selected memory cell. The memory cell is programmed and then verified with a ramped read voltage. The read voltage that turns on the memory cell is stored in the sample and hold circuit. The target threshold voltage is compared with the read voltage by a comparator circuit. When the read voltage is at least substantially equal to (i.e., is substantially equal to and/or starts to exceed) the target threshold voltage, the comparator circuit generates an inhibit signal.

Abstract: A semiconductor memory device includes a bit line pre-sense amplifier configured to sense a potential difference between bit line pair and amplify the voltages of the bit line pair based on the sensed potential difference, a bit line main sense amplifier configured to sense a potential difference between the bit line pair and amplify the voltages of the bit line pair to first and second driving voltages based on the sensed potential difference, and a power supplying controller configured to supply the second driving voltage to the bit line pre-sense amplifier and the bit line main sense amplifier.

Abstract: A memory with extra digit lines in full size end arrays with an open digit architecture, which can use the extra digit lines to form repair cells. In one example, folded digit sense amplifiers are connected to an end array with an open digit architecture such that each sense amplifier corresponds to a group of four digit lines. Two digit lines of the group connect to two open digit sense amplifiers and the other two digit lines connect to the corresponding folded digit sense amplifier. A repair method can be performed on memories including the end arrays with folded digit sense amplifiers. A row in a core array including a replaceable IO is activated and a row in an end array is activated. The repair cells in the end array can be sensed by the folded digit sense amplifiers to generate a replacement IO, which is selected rather than the replaceable IO.

Abstract: The present disclosure includes apparatuses and methods related to performing compare and/or report operations using sensing circuitry. An example method can include charging an input/output (IO) line of a memory array to a voltage. The method can include determining whether data stored in the memory array matches a compare value. The determination of whether data stored matches a compare value can include activating a number of access lines of the memory array. The determination can include sensing a number of memory cells coupled to the number of access lines. The determination can include sensing whether the voltage of the IO line changes in response to activation of selected decode lines corresponding to the number of memory cells.

Abstract: A semiconductor device comprises first and second global bit lines, a sense amplifier amplifying a voltage difference of the first and second global bit lines, first and second local bit lines corresponding to the first and second global bit lines, and first and second hierarchical switches controlling electrical connections between the first and second global bit lines and the first and second local bit line. In a precharge operation prior to accessing a selected memory cell belong to the first local bit lines, a pair of the first and second hierarchical switches, which is not in an access path, is kept ON, and remaining ones thereof are kept OFF. Subsequently, in an access to the selected memory cell, a first hierarchical switch of the pair is switched from ON to OFF, and simultaneously a first hierarchical switches in the access path is switched from OFF to ON.

Abstract: A semiconductor storage apparatus according to the present invention includes a plurality of memory cells, a plurality of word lines, a plurality of pairs of bit lines, a plurality of sense amplifiers, a pair of common data lines, a data-to-be-written output circuit configured to, in writing data, set voltages of the common data lines forming the pair, a column selection signal output unit configured to output a plurality of column selection signals, and a plurality of column selection gates, in which in writing the data, the column selection signal output unit selectively turns on one of the column selection gates by setting each of voltages of the column selection signals to one of a level of a higher-potential power supply voltage and a level of a lower-potential power supply voltage, before activating the sense amplifiers.

Abstract: Apparatus and methods level shift a direct current (DC) component of a voltage rail signal from a first DC level to a second DC level such that voltage rail noise can be determined. The actual voltage rail noise can be compared to an expected amount of noise for analysis and validation of simulation models. Such assessment can be used to validate simulation models used to refine a design of an integrated circuit or as part of built-in self test.

Abstract: A data readout circuit of phase change memory, relating to one or more phase change memory cells, wherein each phase change memory cell is connected to the control circuit by bit line and word line; said data readout circuit comprises: a clamp voltage generating circuit, used to generate a clamp voltage; a precharge circuit, used to fast charge bit line under the control of a clamp voltage; a clamped current generating circuit, used to generate a clamped current to keep bit line at clamped state under the control of a clamp voltage; a clamped current operation circuit, used to perform subtraction and multiplication on clamped current to increase the difference of clamped current between high resistance state and low resistance state; a sense amplifier circuit, used to compare the operated clamped current and the reference current and output the readout result.