A read-write circuit, method and array of a probabilistic device

Abstract

The present application provides a read-write circuit, method and array of a probability device, and relates to the field of integrated circuit design technology. It includes a bias module, a probability device, an initialization substrate voltage module and a monitoring module. The bias module is connected to the first end of the probability device, the first end of the initialization substrate voltage module is connected to the second end of the probability device, and the second end is connected to the monitoring module. The bias module is used to provide a write current to the probability device; the probability device is biased to the corresponding resistance state under the action of the write current; the initialization substrate voltage module is used to generate an initialization voltage and provide a read current to the probability device, and the probability device generates a read voltage at its second end according to the read current and the corresponding resistance state. The initialization substrate voltage module is also used to generate a comparison voltage according to the read voltage and the initialization voltage, and output it to the monitoring module; the monitoring module is used to output the resistance state of the probability device according to the comparison voltage. The present application can prevent the write operation from interfering with the read operation.

Description

Technical Field

[0001] The present application relates to the technical field of integrated circuit design, and in particular to a read / write circuit, method and array of a probabilistic device. Background Art

[0002] With the rapid development of the integrated circuit industry, probabilistic computing is increasingly being used in the fields of artificial intelligence, big data, and the Internet of Things. At present, quantum computing systems are often used for probabilistic computing, but the state of quantum bits, the basic unit of quantum computing systems, is difficult to maintain and has high requirements for the working environment, making it difficult to achieve large-scale integration.

[0003] Since the Magnetic Tunnel Junction (MTJ) has excellent characteristics such as high response speed, low power consumption, and long durability, it is used as the basic unit of Magnetic Random Access Memory (MRAM) and is widely used. Applying MTJ to probability calculation and adjusting the probability by adjusting the MTJ bias voltage can effectively solve the speed and reliability problems in probability calculation.

[0004] However, adjusting the bias voltage of the MTJ will also affect the read voltage of the MTJ. Currently, it is not possible to provide a stable electrical signal that can normally read the state of the MTJ at any bias voltage. Summary of the invention

[0005] The present application provides a read / write circuit, method and array of a probabilistic device, which is used to provide a technical solution that can prevent the write operation from interfering with the read operation, ensure the correct reading of the resistance state of the probabilistic device, and realize simultaneous reading and writing.

[0006] In a first aspect, the present application provides a read / write circuit of a probabilistic device, including a probabilistic device, a bias module, an initialization substrate voltage module, and a monitoring module.

[0007] The bias module is connected to a first end of the probability device, the first end of the initialization base voltage module is connected to a second end of the probability device, and the second end is connected to the monitoring module.

[0008] The bias module is used to provide a write current to the probabilistic device; the probabilistic device is biased to a corresponding resistance state under the action of the write current; the initialization base voltage module is used to generate an initialization voltage and provide a read current to the probabilistic device so that it generates a read voltage, and the initialization base voltage module is also used to generate a comparison voltage based on the read voltage and the initialization voltage, and output it to the monitoring module; the monitoring module is used to generate the resistance state of the probabilistic device based on the comparison voltage.

[0009] In an optional implementation, the initialization substrate voltage module includes a reading unit and an initialization voltage unit.

[0010] The reading unit is used to provide a reading current to the probabilistic device.

[0011] The first end of the initialization voltage unit is connected to the initialization voltage end, the second end is connected to the second end of the probability device, and the third end is connected to the first end of the monitoring module, and is used to generate the initialization voltage and output the comparison voltage generated according to the read voltage and the initialization voltage to the monitoring module.

[0012] In an optional embodiment, the initialization voltage unit includes a switching element and a filtering element, the first end of the switching element is used to connect to the initialization voltage end, the second end is connected to the first end of the filtering element and the first end of the monitoring module, the control end is connected to the control signal end, and the second end of the filtering element is connected to the second end of the probability device.

[0013] The switch element is used to change the voltage across the filter element under the control of the signal generated at the control signal terminal.

[0014] In a possible implementation, the probability of the probabilistic device being biased to a corresponding resistance state under the action of different write currents is different.

[0015] The probabilistic device is a device obtained by special processing of the magnetic tunnel junction, and the special processing method includes: changing the thickness of the free layer of the probabilistic device and changing the ratio of the major axis to the minor axis of the probabilistic device.

[0016] In one possible implementation, the initialization base voltage module is also connected to the power supply voltage terminal to generate the read current; the sum of the initialization voltage and the voltage obtained by multiplying the read current by the first resistance value of the probability device is less than or equal to the power supply voltage provided by the power supply voltage terminal.

[0017] In a possible implementation, the bias module includes a digital-to-analog converter, which is connected to the first end of the probability device and is used to convert the input bias parameter into the write current; the write current changes based on the change value of the bias parameter.

[0018] In a possible implementation manner, the monitoring module includes a comparator.

[0019] The first input terminal of the comparator is connected to the second terminal of the initialization base voltage module, and the second input terminal of the comparator is connected to the reference voltage terminal, so as to determine the resistance state of the probability device according to the comparison voltage and the reference voltage.

[0020] In one possible implementation, the range of the reference voltage is greater than the sum of the voltage obtained by multiplying the initialization voltage and the read current by the second resistance of the probability device, and less than the sum of the voltage obtained by multiplying the initialization voltage and the read current by the first resistance of the probability device.

[0021] In a second aspect, the present application further provides a read-write array, comprising: a plurality of read-write circuits as described in any one of the first aspects arranged in an array; the plurality of probabilistic devices in the read-write array can realize parallel reading and writing.

[0022] In a third aspect, the present application also provides a method for reading and writing a probabilistic device, comprising the following steps:

[0023] A write current is provided to the probabilistic device, and the probabilistic device is biased to a corresponding resistance state under the effect of the write current.

[0024] A read current is provided to the probabilistic device, and the probabilistic device generates a read voltage according to the read current and the corresponding resistance state.

[0025] A comparison voltage is generated according to the read voltage and the initialization voltage, and a resistance state of the probabilistic device is determined according to the comparison voltage.

[0026] The technical solution provided by the present application, the bias module is used to provide different write currents for the probability device, bias the probability device in the corresponding resistance state, and generate different substrate voltages. The different substrate voltages will affect the subsequent reading operation. Based on this, the initialization substrate voltage module in the present application is used to provide an initialization voltage, and use the initialization voltage to unify different substrate voltages. The initialization substrate voltage module is also used to provide a read current to the probability device, and the probability device generates a read voltage at its second end according to the read current and the corresponding resistance state, and generates a comparison voltage according to the read voltage and the above-mentioned initialization voltage. The monitoring module is used to generate the resistance state of the probability device according to the comparison voltage. It should be understood that since the read voltage is related to the resistance state of the probability device, the comparison voltage generated by the read voltage can reflect the resistance state of the probability device. Therefore, after comparing the comparison voltage with the reference voltage in the monitoring module, a logical output is performed, and the resistance state of the probability device can be accurately determined.

[0027] Based on the above description, the present application can unify the different base voltages generated by different write currents into an initialization voltage, filter out the fluctuating base voltage, effectively avoid the interference of the write operation of the probabilistic device on the read operation, and realize simultaneous reading and writing of the probabilistic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0029] Figure 1 A circuit diagram of a read / write circuit of a probabilistic device provided in an embodiment of the present application;

[0030] Figure 2 A circuit diagram of a bias module provided in an embodiment of the present application;

[0031] Figure 3 A circuit diagram of a substrate voltage initialization module provided in an embodiment of the present application;

[0032] Figure 4 A circuit diagram of a monitoring module provided in an embodiment of the present application;

[0033] Figure 5 A flowchart of a read-write circuit of a probabilistic device provided in an embodiment of the present application;

[0034] Figure 6 This is a working waveform diagram of the read-write circuit of a probabilistic device provided in an embodiment of the present application.

[0035] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0036] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. It is understood that the terms "first", "second", etc. used in the present application can be used to describe various information or data in this article, but these elements are not limited by these terms. These terms are only used to distinguish the first information from another information. For example, without departing from the scope of the present application, the first action information can be referred to as the second action information, and similarly, the second action information can be referred to as the first action information. Both the first action information and the second action information are action information, but they are not the same action information.

[0038] With the rapid development of the integrated circuit industry, probabilistic computing is increasingly being used in the fields of artificial intelligence, big data, and the Internet of Things. At present, quantum computing systems are often used for probabilistic computing, but the state of quantum bits, the basic unit of quantum computing systems, is difficult to maintain and has high requirements for the working environment, making it difficult to achieve large-scale integration.

[0039] Since the Magnetic Tunnel Junction (MTJ) has excellent characteristics such as high response speed, low power consumption, and long durability, it is used as the basic unit of Magnetic Random Access Memory (MRAM) and is widely used. Applying MTJ to probability calculation and adjusting the probability by adjusting the MTJ bias voltage can effectively solve the speed and reliability problems in probability calculation.

[0040] However, adjusting the bias voltage of the MTJ will also affect the read voltage of the MTJ. Currently, it is not possible to provide a stable electrical signal that can normally read the state of the MTJ at any bias voltage.

[0041] In response to the above problems, the present application provides a read / write circuit, method and probability calculation unit of a probabilistic device, which unifies different base voltages caused by different write currents into an initialization voltage, thereby avoiding the influence of the write operation on the read operation.

[0042] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0043] First, refer to Figure 1An embodiment of the present application provides a read / write circuit of a probabilistic device, including a bias module 10 , an initialization base voltage module 20 , a monitoring module 30 and a probabilistic device 40 .

[0044] The bias module 10 is connected to a first end of the probability device 40 , the first end of the initialization base voltage module 20 is connected to a second end of the probability device 40 , and the second end is connected to the monitoring module 30 .

[0045] The bias module 10 is used to provide a write current to the probabilistic device 40; the probabilistic device 40 is biased to a corresponding resistance state under the effect of the write current, and generates a substrate voltage according to the write current.

[0046] Optionally, the bias module 10 is used to provide different write currents Iwrite to the probabilistic device 40. Under different write currents Iwrite, the probabilistic device 40 will be biased to a corresponding resistance state with different probabilities, and the probabilistic device 40 can also generate different substrate voltages according to different write currents Iwrite. It should be understood that the different substrate voltages may interfere with the subsequent read operation of the probabilistic device 40.

[0047] The above-mentioned initialization base voltage module 20 is used to generate an initialization voltage, and the initialization voltage is used to unify different base voltages. The initialization base voltage module 20 is also used to provide a read current to the probability device 40, and the probability device 40 generates a read voltage at its second end according to the read current and the corresponding resistance state. The initialization base voltage module 20 is also used to generate a comparison voltage according to the read voltage and the initialization voltage, and output it to the monitoring module 30; the monitoring module 30 is used to determine the resistance state of the probability device 40 according to the comparison voltage. It should be understood that since the read voltage is related to the resistance state of the probability device 40, the comparison voltage generated by the read voltage can reflect the resistance state of the probability device 40.

[0048] Based on the above description, the embodiment of the present application can unify the different base voltages generated by different write currents into an initialization voltage, filter out the fluctuating base voltage, effectively avoid the interference of the write operation of the probabilistic device on the read operation, and realize simultaneous reading and writing of the probabilistic device.

[0049] The above content describes the overall structure and function of the read-write circuit of the probabilistic device. The following describes the structure and function of each module separately.

[0050] Optionally, the probability device 40 may be a SOT-MTJ (Spin-Orbit Torque Magnetic Tunnel Junction) device, whose Chinese name is a spin-orbit torque magnetic tunnel junction device. The SOT-MTJ device combines spin-orbit torque and magnetic tunnel junction technology. Due to the fast response characteristics of SOT, the SOT-MTJ device can achieve high-speed write operations. Compared with traditional STT-MRAM (spin transfer torque MRAM), the SOT-MTJ device has less loss on the magnetic layer during the writing process, and thus has higher reliability.

[0051] In a SOT-MTJ device, when the write current flowing through the substrate resistor is different, the SOT-MTJ flips to the corresponding resistance state with different probabilities.

[0052] That is to say, the probability of the probabilistic device being biased to a corresponding resistance state under the action of different write currents is different.

[0053] In an embodiment of the present application, the above-mentioned probabilistic device can be a device obtained by special processing of the magnetic tunnel junction, and the special processing method includes: changing the thickness of the free layer of the probabilistic device and changing the ratio of the major axis to the minor axis of the probabilistic device.

[0054] Among them, the magnetic tunnel junction is a device based on the tunneling magnetoresistance (TMR) effect. By changing the structural parameters of the MTJ, such as the thickness of the free layer and the ratio of the major and minor axes, its magnetic and electrical properties can be adjusted, thereby affecting its working performance and the probability distribution of the output signal. The free layer is a layer in the MTJ that can freely change the magnetization direction. Changing the thickness of the free layer will affect the difficulty of its magnetization reversal, thereby changing the tunnel magnetoresistance effect of the MTJ.

[0055] For example, increasing the thickness of the free layer may increase the magnetic anisotropy of the free layer, making magnetization switching more difficult, thereby changing the switching probability of the MTJ. Reducing the thickness of the free layer may reduce the magnetic anisotropy of the free layer, making magnetization switching easier, thereby changing the switching probability of the MTJ.

[0056] The shape anisotropy of MTJ will also affect its magnetization reversal behavior. By changing the ratio of the long and short axes of MTJ, its shape anisotropy can be adjusted, thereby affecting the probability distribution of its magnetization reversal. For example: increasing the ratio of the long and short axes may increase the shape anisotropy, making the magnetization direction more inclined along the long axis, thereby changing the reversal probability of MTJ. Reducing the ratio of the long and short axes may reduce the shape anisotropy, making the magnetization direction easier to flip, thereby changing the reversal probability of MTJ.

[0057] Through the above special processing, the probability distribution of the output signal of the probabilistic device can be adjusted. For example, the resistance state (high resistance state and low resistance state) of the MTJ can be regarded as a binary output (0 and 1), and its occurrence probability can be controlled by adjusting the free layer thickness and the ratio of the major axis to the minor axis. Figure 2 The bias module includes a digital-to-analog converter, which is connected to the first terminal T2 of the probability device 40, and is used to convert the bias parameter input externally into the above-mentioned write current Iwrite, and input the write current to the T2 terminal of the probability device 40, and the T3 terminal of the probability device is grounded. Among them, the first terminal T2 of the probability device is one end of the MTJ, the T3 terminal of the probability device is the other end of the MTJ, and the T1 terminal of the probability device is the end of the SOT away from the MTJ.

[0058] It should be understood that the digital-to-analog converter is used to generate different write currents Iwrite according to different bias parameters. The probability device 40 can flip to the corresponding resistance state with different probabilities according to different write currents to generate different substrate voltages. Among them, the resistance state can include a high resistance state and a low resistance state.

[0059] In a specific example, the substrate voltage Vh may be the write current Iwrite multiplied by the substrate resistance / 2, that is, Vh=(Iwrite*Rh / 2).

[0060] Optional, see Figure 3 , the initialization substrate voltage module includes a reading unit 202 and an initialization voltage unit 201;

[0061] The first terminal of the reading unit 202 is connected to the power supply voltage terminal VDD, and the second terminal is connected to the second terminal T1 of the probabilistic device 40 , so as to provide a reading current to the probabilistic device 40 .

[0062] The first end of the initialization voltage unit 201 is used to connect to the initialization voltage end, the second end is connected to the second end of the probability device 40, and the third end is connected to the first end of the monitoring module, and is used to generate the initialization voltage Vpre, and output the comparison voltage Vdata generated according to the read voltage and the initialization voltage Vpre to the monitoring module.

[0063] Based on the above structure, the second end of the reading unit 202 and the second end of the initialization voltage unit 201 are the first end of the initialization base voltage module. The third end of the initialization voltage unit 201 is the second end of the initialization base voltage module.

[0064] It should be understood that based on the different write currents generated by the above-mentioned bias module, different resistance states and substrate voltages are generated in the probabilistic device, and different substrate voltages will interfere with the reading operation. Based on this, the first end of the initialization voltage unit 201 is connected to the initialization voltage end, which is used to introduce the initialization voltage Vpre in the initialization voltage end into the initialization voltage unit 201, and use the initialization voltage to unify the different substrate voltages to avoid interference with the reading operation, thereby realizing simultaneous reading and writing.

[0065] The reading unit 202 generates a reading current based on the power supply voltage VDD provided by the power supply voltage terminal, and provides it to the second terminal of the probability device. The probability device generates a reading voltage at its second terminal according to the reading current and the corresponding resistance state. The initialization base voltage module 201 is also used to generate a comparison voltage Vdata according to the reading voltage and the initialization voltage Vpre, and output it to the monitoring module. The comparison voltage Vdata is a voltage generated based on the resistance state of the probability device, so it is related to the resistance state of the probability device, and the current resistance state of the probability device can be determined according to the comparison voltage.

[0066] The initialization voltage unit may include a switch element and a filter element.

[0067] The filter element may be any suitable element, which is not specifically limited in the present embodiment, for example, the filter element is a capacitor element. The switch element may be any suitable switch element, which is not specifically limited in the present embodiment, for example, the switch element is a semiconductor switch.

[0068] Reference Figure 3 In one example, the initialization voltage unit 201 includes a switching element S0 and a capacitor element C0, the first end of the switching element S0 is used to connect the initialization voltage end, and the second end is connected to the first end of the capacitor element C0 and the first end of the monitoring module, the switching element is also used to connect the control signal end, and the second end of the capacitor element C0 is used to connect the second end of the probability device 40.

[0069] Reference Figure 3 The switch element is used to be turned on when the signal generated by the control signal end is a first control signal, and turned off when the signal generated by the control signal end is a second control signal. When the switch element is turned on, the voltage at the first end of the filter element is the initialization voltage, and the voltage at the second end is the base voltage, wherein the base voltage is the voltage generated by the probability device under the action of the write current.

[0070] It should be understood that the initialization voltage unit 201 can unify different substrate voltages into an initialization voltage at the first end of the filter element to avoid interference with the read operation.

[0071] Reference Figure 3The reading unit may include a first switch tube P1 and a second switch tube N1; the first end of the first switch tube P1 is used to connect to the power supply voltage end, the second end is connected to the second end of the probability device 40 through the second switch tube N1, and the third end is used to connect to the control signal end Vct.

[0072] For example, the first switch tube P1 is a PMOS transistor, and the second switch tube N1 is an NMOS transistor.

[0073] It is worth noting that the control logic of the first switch tube P1 is to turn on when the control signal is low, and the second switch tube N1 is a clamping transistor used to control the reading current. Due to the existence of the TMR effect, it is necessary to select a suitable reading current. At the same time, it is necessary to select a suitable initialization voltage Vpre so that the voltage fluctuation does not exceed the power supply voltage.

[0074] Based on this, the embodiment of the present application can be set as follows: the sum of the initialization voltage and the voltage obtained by multiplying the read current by the first resistance value of the probability device is less than or equal to the power supply voltage provided by the power supply voltage terminal. So that the selection of the initialization voltage and the read current conforms to the above principles. Among them, the first resistance value can be the resistance value exhibited by the probability device when the magnetization directions of the free layer and the reference layer in the probability device are antiparallel, that is, in a high resistance state.

[0075] The first switch tube P1 is used to be turned on under the control of the second control signal and turned off under the control of the first control signal. When the first switch tube P1 is turned on, the second switch tube N1 is used to provide a read current to the probability device 40.

[0076] In this embodiment, the first switch tube P1 is turned on after the switch element S0 is turned off, and then the power supply voltage terminal provides a read current to the second end of the probability device 40 through the first switch tube P1 and the second switch tube N1, and the probability device generates a read voltage at its second end according to the read current and the corresponding resistance state generated previously. At this time, the voltage at the second end of the probability device is the read voltage plus the base voltage. Since the second end of the filter element C0 is used to connect the second end of the probability device 40, the voltage at the second end of the filter element C0 is also the read voltage plus the base voltage. That is to say, compared with the previous, the voltage at the second end of the filter element C0 increases by a voltage of the magnitude of the read voltage. Then, according to the characteristics of the filter element, the voltage at its first end will also increase by a voltage of the magnitude of the read voltage accordingly, that is, at this time, the voltage at the first end of the filter element C0 is the initialization voltage plus the read voltage. The initialization voltage unit 201 outputs the initialization voltage plus the read voltage (the above-mentioned comparison voltage) to the monitoring module to determine the current resistance state of the probability device.

[0077] Reference Figure 4, the monitoring module includes a comparator; the first input end of the comparator is connected to the second end of the initialization base voltage module, and the second input end of the comparator is used to connect to the reference voltage end, and is used to determine the resistance state of the probability device according to the comparison voltage Vdata and the reference voltage Vref.

[0078] Among them, the above-mentioned comparator can be a static comparator or a dynamic comparator, and the comparator can also be replaced by other devices with the same function. This embodiment of the present application does not make any special limitation on this.

[0079] It should be understood that, since the read voltage is related to the resistance state of the probabilistic device, the comparison voltage generated by the read voltage can reflect the resistance state of the probabilistic device, so the resistance state of the probabilistic device can be determined according to the comparison voltage.

[0080] Optionally, the range of the reference voltage is greater than the sum of the voltage obtained by multiplying the initialization voltage and the read current by the second resistance value of the probability device, and less than the sum of the voltage obtained by multiplying the initialization voltage and the read current by the first resistance value of the probability device. The first resistance value is the resistance value exhibited by the probability device when the magnetization directions of the free layer and the reference layer in the probability device are antiparallel, that is, in a high resistance state, and the second resistance value is the resistance value exhibited by the probability device when the magnetization directions of the free layer and the reference layer in the probability device are parallel, that is, in a low resistance state; the first resistance value is greater than the second resistance value.

[0081] Based on this, when the current resistance state of the probability device is low resistance state, the above comparison voltage is less than the reference voltage, at this time, the comparator can output 0 to indicate that the current resistance state of the probability device is low resistance state. When the current resistance state of the probability device is high resistance state, the above comparison voltage is greater than the reference voltage, at this time, the comparator can output 1 to indicate that the current resistance state of the probability device is high resistance state.

[0082] Therefore, the embodiments of the present application can accurately determine the current resistance state of the probabilistic device.

[0083] The following content describes the structure and function of the probability device of the present application using a specific embodiment.

[0084] The bias module provides different write currents for the probabilistic device according to the bias parameters, biases the probabilistic device in different states, and generates different substrate voltages. The probabilistic device is a SOT-MTJ device. When the current flowing through the substrate resistor is different, the resistance state of the SOT-MTJ will be presented with different probabilities.

[0085] The initialization substrate voltage module unifies the different substrate voltages caused by different write currents into an initial voltage. The read voltage fluctuates on this basis. The voltage fluctuation is caused by the read current flowing into the top of the MTJ. The fluctuation is based on the change of the MTJ resistance state. When the MTJ changes from a low resistance state to a high resistance state, the read voltage changes from a low voltage to a high voltage. When the MTJ changes from a high resistance state to a low resistance state, the read voltage changes from a high voltage to a low voltage. The monitoring module is responsible for monitoring the state flip of the device, and a static or dynamic comparator can be used.

[0086] The bias module uses a digital-to-analog converter to provide different bias currents for the MTJ. The probability device uses a specially processed SOT-MTJ, which has different probabilities of presenting different resistance states when the writing current is different.

[0087] Reference Figure 3 The initialization base voltage module consists of a PMOS transistor P1, an NMOS transistor N1, a capacitor C0, and a switch S0. The control logic of P1 is to turn on when the control signal is low. N1 is a clamping transistor used to control the reading current. Due to the existence of the TMR effect, it is necessary to select a suitable reading current. At the same time, it is necessary to select a suitable initialization voltage V pre Make sure the voltage fluctuation does not exceed the power supply voltage.

[0088] Figure 4 This is a structural diagram of the monitoring module of an embodiment of the present invention. The monitoring module adopts a static comparator circuit, wherein the data terminal voltage is connected to the initialization base voltage module output comparison voltage Vdata, and the reference terminal voltage selects the voltage reference voltage Vref. The reference voltage Vref should be greater than the sum of the voltage obtained by multiplying the read current by the second resistor and the initialization voltage, and less than the sum of the voltage obtained by multiplying the read current by the first resistor and the initialization voltage.

[0089] Figure 5 This is the working flow diagram of this embodiment,

[0090] In the first step, the bias circuit generates a bias current according to the input bias parameters. The bias current is the write current of the MTJ in the probability device. At this time, the probability device generates a voltage Vh at the T1 end of the MTJ. The voltage Vh is the write current multiplied by the substrate resistance of the probability device / 2.

[0091] The second step is to initialize the substrate voltage module to work, the switch S0 is closed, the voltage on one side of the capacitor C0 is Vh, and the voltage on the other side is the initialization voltage Vpre, the transistor P1 is turned on, and the voltage on one side of the capacitor C0 becomes the sum of the voltage obtained by multiplying the read current by the MTJ resistance and the substrate voltage, at this time, the voltage on the other side becomes the sum of the voltage obtained by multiplying the read current by the MTJ resistance and the initialization voltage;

[0092] In the third step, the monitoring module works to compare the comparison voltage Vdata with the reference voltage Vref. If the comparison voltage Vdata> the reference voltage Vref, the output terminal OUT is logic 1; if the comparison voltage Vdata< the reference voltage Vref, the output terminal OUT is logic 0.

[0093] Step 4: Output the state of the MTJ; the state of the MTJ includes high impedance and low impedance. If the output terminal OUT is logic 1, the state of the MTJ is high impedance; if the output terminal OUT is logic 0, the state of the MTJ is low impedance;

[0094] The fifth step is to determine whether the bias parameter input to the bias circuit has changed. If the bias parameter has changed, jump to the second step to continue working. If not, jump to the third step to continue working.

[0095] Figure 6 This is a working waveform diagram of the embodiment of the present application. It can be seen that the voltage fluctuation at the second end of the probability device will cause the reference voltage to fail for different bias currents, while the comparison voltage Vdata of the initialized substrate voltage module has good consistency with the reference voltage Vref.

[0096] In a second aspect, the present application further provides a read-write array, comprising: a plurality of read-write circuits as described in any one of the first aspects arranged in an array; the plurality of probabilistic devices in the read-write array can realize parallel reading and writing.

[0097] The read / write array can be integrated into a chip to realize parallel reading and writing of multiple probabilistic devices.

[0098] It should be understood that since the read-write array includes the above-mentioned read-write circuit, the read-write array is Figure 1-Figure 6 The beneficial effects of the read / write circuit provided in the illustrated embodiment are the same and will not be described in detail here. In a third aspect, the present application also provides a read / write method for a probabilistic device, comprising the following steps:

[0099] A write current is provided to the probabilistic device, and the probabilistic device is biased to a corresponding resistance state under the effect of the write current.

[0100] A read current is provided to the probabilistic device, and the probabilistic device generates a read voltage according to the read current and the corresponding resistance state.

[0101] A comparison voltage is generated according to the read voltage and the initialization voltage, and a resistance state of the probabilistic device is determined according to the comparison voltage.

[0102] The read-write method provided in the present application provides different write currents to the probability device to bias the probability device in the corresponding resistance state and generate different substrate voltages. It should be understood that the different substrate voltages will affect the subsequent reading operation. Based on this, the initialization voltage is used in the present application to unify the different substrate voltages. The read-write method is also used to provide a read current to the probability device, and the probability device generates a read voltage according to the read current and the corresponding resistance state, and generates a comparison voltage according to the read voltage and the above-mentioned initialization voltage, and further determines the resistance state of the probability device according to the comparison voltage. It should be understood that since the read voltage is related to the resistance state of the probability device, the comparison voltage generated by the read voltage can reflect the resistance state of the probability device, so after comparing the comparison voltage with the reference voltage in the monitoring module, a logical output is performed, and the resistance state of the probability device can be accurately determined.

[0103] Based on the above description, the embodiment of the present application can unify the different base voltages generated by different write currents into an initialization voltage, filter out the fluctuating base voltage, effectively avoid the interference of the write operation of the probabilistic device on the read operation, and realize simultaneous reading and writing of the probabilistic device.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A read / write circuit of a probabilistic device, characterized in that: It includes a bias module, a probability device, an initialization substrate voltage module and a monitoring module; The bias module is connected to the first end of the probability device, the first end of the initialization base voltage module is connected to the second end of the probability device, and the second end is connected to the monitoring module; The bias module is used to provide a write current to the probabilistic device; The probabilistic device is biased to a corresponding resistance state under the effect of the write current, and generates a substrate voltage according to the write current; The initialization substrate voltage module includes a reading unit and an initialization voltage unit; The reading unit is used to provide a reading current to the probabilistic device to generate a reading voltage; The first end of the initialization voltage unit is connected to the initialization voltage end, the second end is connected to the second end of the probability device, and the third end is connected to the first end of the monitoring module, and is used to provide the initialization voltage and output a comparison voltage generated according to the read voltage and the initialization voltage to the monitoring module; The initialization voltage unit comprises a switch element and a filter element, wherein the first end of the switch element is connected to the initialization voltage end, the second end is connected to the first end of the filter element and the first end of the monitoring module, the control end is connected to the control signal end, and the second end of the filter element is connected to the second end of the probability device; The switch element is used to change the voltage across the filter element under the control of the signal generated by the control signal terminal; The monitoring module is used to determine the resistance state of the probabilistic device according to the comparison voltage.

2. The read / write circuit of the probabilistic device according to claim 1, characterized in that: The initialization substrate voltage module is also connected to the power supply voltage terminal to generate the read current, and the sum of the initialization voltage and the voltage obtained by multiplying the read current by the first resistance value of the probability device is less than or equal to the power supply voltage provided by the power supply voltage terminal.

3. The read / write circuit of the probabilistic device according to claim 1 or 2, characterized in that: The probability of the probabilistic device being biased to a corresponding resistance state under the action of different write currents is different; The probabilistic device is a device obtained by special processing of the magnetic tunnel junction, and the special processing includes: changing the thickness of the free layer of the probabilistic device and / or changing the ratio of the major axis to the minor axis of the probabilistic device.

4. The read / write circuit of the probabilistic device according to claim 1 or 2, characterized in that: The bias module includes a digital-to-analog converter, which is connected to the first end of the probability device and is used to convert the input bias parameter into the write current; the write current changes based on the change value of the bias parameter.

5. The read / write circuit of the probabilistic device according to claim 1 or 2, characterized in that: The monitoring module includes a comparator; The first input terminal of the comparator is connected to the second terminal of the initialization base voltage module, and the second input terminal of the comparator is connected to the reference voltage terminal, so as to determine the resistance state of the probability device according to the comparison voltage and the reference voltage.

6. The read / write circuit of the probabilistic device according to claim 5, characterized in that: The reference voltage has a range greater than the sum of the voltage obtained by multiplying the initialization voltage and the read current by the second resistance of the probability device, and less than the sum of the voltage obtained by multiplying the initialization voltage and the read current by the first resistance of the probability device.

7. A read-write array, characterized in that: include: A plurality of read / write circuits as claimed in any one of claims 1 to 6 arranged in an array; The plurality of probabilistic devices in the read-write array can realize parallel reading and writing.

8. A method for reading and writing a probabilistic device, characterized in that: The read / write circuit according to any one of claims 1 to 6 comprises the following steps: Providing a write current to the probabilistic device, wherein the probabilistic device is biased to a corresponding resistance state under the effect of the write current; Providing a read current to the probabilistic device, wherein the probabilistic device generates a read voltage according to the read current and the corresponding resistance state; A comparison voltage is generated according to the read voltage and the initialization voltage, and a resistance state of the probabilistic device is determined according to the comparison voltage.

Images