阅读说明：本技术 一种Toffoli门电路及其操作方法 (Toffoli gate circuit and operation method thereof ) 是由 李祎 程龙 缪向水 于 2019-08-09 设计创作，主要内容包括：本发明公开了一种Toffoli门电路及其操作方法,其中Toffoli门电路包括控制位忆阻器、操作位忆阻器、控制器,其中控制位忆阻器和操作位忆阻器的正极共同连接在一条阵列字线上,负极分别连接在不同的阵列位线上。利用忆阻器在不同操作电压下具有多阻态的特点,通过分别在控制位忆阻器和操作位忆阻器所在的字线和位线上输入不同的控制信号来控制忆阻器两端输入的电压从而改变忆阻器的状态,进而分别存储控制位信息和操作位信息。本发明仅采用两个忆阻器即可实现Toffoli可逆逻辑功能,电路复杂度较低,电路所占面积也较小。同时由于忆阻器具有非易失的特点,在逻辑功能完成后,逻辑输出直接存储在忆阻器中,无需额外的数据传输与存储,故延时及功耗较低。(the invention discloses a Toffoli gate circuit and an operation method thereof, wherein the Toffoli gate circuit comprises a control bit memristor, an operation bit memristor and a controller, wherein the positive electrodes of the control bit memristor and the operation bit memristor are connected to one array word line together, and the negative electrodes of the control bit memristor and the operation bit memristor are connected to different array bit lines respectively. The characteristics that the memristor has multiple resistance states under different operating voltages are utilized, different control signals are respectively input to word lines and bit lines where the control bit memristor and the operating bit memristor are located to control voltages input to two ends of the memristor, so that the state of the memristor is changed, and then control bit information and operating bit information are respectively stored. The invention can realize Toffoli reversible logic function only by adopting two memristors, and has lower circuit complexity and smaller occupied area of the circuit. Meanwhile, the memristor has the characteristic of non-volatility, after the logic function is completed, the logic output is directly stored in the memristor, and extra data transmission and storage are not needed, so that the time delay and the power consumption are low.)

1. A Toffoli gate circuit is characterized by comprising a control bit memristor, an operation bit memristor and a controller;

The control bit memristor and the operation bit memristor have anodes commonly connected to one array word line, and cathodes respectively connected to different array bit lines;

the control bit memristor is used for storing two-bit control bit information by changing the resistance state of the control bit memristor according to the voltage input by the controller;

The operation bit memristor is used for changing the resistance state of the operation bit memristor according to the voltage input by the controller so as to store one bit of operation bit information;

the controller is used for respectively controlling the voltages on the word line and the bit line where the control bit memristor and the operation bit memristor are located according to the logic operation rule of the Toffoli gate circuit.

2. The toffil gate circuit of claim 1, wherein the control bit memristor comprises a first state, a second state, a third state, and a fourth state for representing two-bit control bit information "00", "01", "10", "11", respectively;

The first state and the fourth state of the control bit memristor respectively correspond to the highest resistance state and the lowest resistance state of the control bit memristor; the second state and the third state of the control bit memristor are both intermediate resistance states of the control bit memristor.

3. the toffil gate circuit of claim 1, wherein the operational bit memristor comprises a first state and a fourth state for representing one bit of operational bit information "0" and "1", respectively;

the first state and the fourth state of the operation bit memristor respectively correspond to the highest resistance state and the lowest resistance state of the operation bit memristor.

4. a method of operating a toffil gate circuit, comprising the steps of:

s1, dividing the three-bit input information into two-bit control bit information and one-bit operation bit information;

S2, writing control bit information into the control bit memristor according to the control signal;

s3, if the control bit information is '11', inverting the operation bit information and writing the operation bit information into the operation bit memristor according to the control signal; otherwise, directly writing the operation bit information into the operation bit memristor according to the control signal;

S4, reading the states of the control bit memristor and the operation bit memristor at the moment, namely the result of Toffoli reversible logic operation.

5. The method according to claim 4, wherein the control signal comprises an initialization signal, a voltage direction signal, and an operation voltage signal, which are respectively 0 or 1, and the operation voltage signal comprises an operation voltage signal A and an operation voltage signal B;

The initialization signal is used to control an initialization state of a memristor;

the voltage direction signal is used to control the direction of a voltage applied across the memristor;

the operating voltage signal is used to control the value of the input voltage.

6. The method of operating a Toffoli gate circuit of claim 4, wherein the method of step S2 includes the steps of:

S21, initializing the control bit memristor according to the initialization signal;

s22, setting the operation voltage signal A to be 1 and setting the operation voltage signal B to be 0;

S23, respectively inputting corresponding operating voltage signals on the bit line and the word line where the control bit memristor is located according to the voltage direction signal;

And S24, applying corresponding operating voltages on the bit line and the word line where the control bit memristor is located according to the value of the operating voltage signal, and completing writing of control bit information.

7. The method of operating a toffil gate circuit as claimed in claim 6, wherein when the operating voltage signal takes a value of 0, an operating voltage of 0V is applied; when the operating voltage signal takes a value of 1, an operating voltage V2 is applied, where the operating voltage V2 is a voltage that causes the control bit memristor to change from the first state to the second state.

8. the method of operating a Toffoli gate circuit of claim 4, wherein the method of step S3 includes the steps of:

s31, if the control bit information is '11', setting the operation voltage signal A to be 0 and the operation voltage signal B to be 1 for negating the operation bit information; otherwise, setting the operation voltage signal A to be 1 and setting the operation voltage signal B to be 0;

s32, inputting corresponding operating voltage signals on the bit line and the word line where the operating bit memristor is located according to the voltage direction signals;

and S33, applying corresponding operating voltages on the bit line and the word line where the operating bit memristor is located according to the value of the operating voltage signal, and completing the writing of the operating bit information.

9. the method of operating a toffil gate circuit as claimed in claim 8, wherein when the operating voltage signal takes a value of 0, an operating voltage of 0V is applied; when the operating voltage signal takes a value of 1, an operating voltage V1 is applied, where the operating voltage V1 is a voltage that causes the operating bit memristor to change from the other state to the fourth state, and the operating voltage V1 is greater than the operating voltage V2.

10. The method for operating the Toffoli gate circuit according to claim 6 or 8, wherein the method for inputting the corresponding operating voltage signals to the bit line and the word line on which the control bit memristor or the operating bit memristor is located according to the voltage direction signal comprises;

(1) when the voltage direction signal is 0, inputting an operation voltage signal A on a bit line where the control bit memristor or the operation bit memristor is located, and inputting an operation voltage signal B on a word line where the control bit memristor or the operation bit memristor is located;

(2) when the voltage direction signal is 1, an operating voltage signal a is input to a word line where the control bit memristor or the operating bit memristor is located, and an operating voltage signal B is input to a bit line where the control bit memristor the operating bit memristor is located.

Technical Field

the invention belongs to the field of digital circuits, and particularly relates to a Toffoli gate circuit and an operation method thereof.

Background

Since the 1960 s, reversible logic gates were studied, with the initial aim of reducing the energy dissipation of the calculation process, since they in principle do not generate heat during the calculation process. For a typical logic gate, the input state is lost after the operation, which results in output information less than the input information. According to the entropy principle, the loss of information dissipates into the environment in the form of heat. The reversible logic gate only moves the information state from input to output, and information is not lost.

A toffil gate is a reversible logic gate with three inputs and three outputs, also known as a "control-not gate. It is characterized in that: if the first two positions are 1, the third bit will be inverted, otherwise all bits remain unchanged. In computer science, the circuit was first proposed by Tommaso toffee and is a general-purpose reversible logic gate. Since any reversible logic circuit can be constructed by the Toffoli gate, it is of great significance to study the Toffoli gate and its operation method.

At present, the Toffoli gate circuit realized by using the CMOS technology needs an AND logic gate AND an XOR logic gate, AND is built by 12 transistors in total. The transistor size reduction technology is about to reach the bottleneck, and the whole circuit consumes a large area in terms of wiring; meanwhile, the information in the transistor circuit is calculated in the form of voltage, and extra time delay and power consumption are consumed to store the output information.

Therefore, it is an urgent need to provide a toffee gate circuit and its operation method with small area, low delay and low power consumption.

disclosure of Invention

In view of the defects of the prior art, the present invention provides a toffee gate circuit and an operating method thereof, which aims to solve the problem of large circuit area caused by the fact that a required gate circuit is composed of a plurality of transistors in the prior CMOS technology.

In order to achieve the above object, an aspect of the present invention provides a toffil gate circuit, which includes a control bit memristor, an operation bit memristor, and a controller; the control bit memristor and the operation bit memristor are connected with the same array word line through the same connecting line, and the control bit memristor and the operation bit memristor are connected with the same array word line through the same connecting line;

The control bit memristor is used for storing two-bit control bit information by changing the resistance state of the control bit memristor according to the voltage input by the controller;

The operation bit memristor is used for changing the resistance state of the operation bit memristor according to the voltage input by the controller so as to store one bit of operation bit information.

the controller is used for respectively controlling the voltages on the word line and the bit line where the control bit memristor and the operation bit memristor are located according to the logic operation rule of the Toffoli gate circuit.

Further preferably, the control bit memristor comprises a first state, a second state, a third state and a fourth state, which are respectively used for representing two-bit control bit information "00", "01", "10", "11"; the first state and the fourth state of the control bit memristor respectively correspond to the highest resistance state and the lowest resistance state of the control bit memristor; the second state and the third state of the control bit memristor are both intermediate resistance states of the control bit memristor. The four states can be switched by applying different operating voltages between the positive and negative electrodes of the control bit memristors.

further preferably, the operating bit memristor includes a first state and a fourth state for representing one bit of operating bit information "0" and "1", respectively, the first state and the fourth state of the operating bit memristor corresponding to a highest resistance state and a lowest resistance state of the operating bit memristor, respectively. The two states can be switched by applying different operating voltages between the positive and negative electrodes of the operating position memristor.

In another aspect of the present invention, a method for operating a Toffoli gate circuit is provided, comprising the steps of:

s1, dividing the three-bit input information into two-bit control bit information and one-bit operation bit information;

S2, writing control bit information into the control bit memristor according to the control signal;

S3, if the control bit information is '11', inverting the operation bit information and writing the operation bit information into the operation bit memristor according to the control signal; otherwise, directly writing the operation bit information into the operation bit memristor according to the control signal;

S4, reading the states of the control bit memristor and the operation bit memristor at the moment, namely the result of Toffoli reversible logic operation.

Further preferably, the control signal includes an initialization signal, a voltage direction signal, and an operation voltage signal, which are respectively taken as 0 or 1, where the operation voltage signal includes an operation voltage signal a and an operation voltage signal B;

the initialization signal is used for controlling the initialization state of the memristor;

The voltage direction signal is used for controlling the direction of the voltage applied across the memristor;

The operating voltage signal is used to control the value of the input voltage.

Further preferably, the method for writing the control bit information in the control bit memristor in the step S2 includes the following steps:

s21, initializing the control bit memristor according to the initialization signal;

S22, setting the operation voltage signal A to be 1 and setting the operation voltage signal B to be 0;

s23, respectively inputting corresponding operating voltage signals on the bit line and the word line where the control bit memristor is located according to the voltage direction signal;

And S24, applying corresponding operating voltages on the bit line and the word line where the control bit memristor is located according to the value of the input operating voltage signal, and completing the writing of the control bit information.

further preferably, when the operating voltage signal takes a value of 0, an operating voltage of 0V is applied; when the operating voltage signal takes a value of 1, applying an operating voltage V2; wherein the operating voltage V2 is a voltage to cause the control bit memristor to change from a first state to a second state.

further preferably, the method for writing the operation bit voltage signal in step S3 includes:

S31, if the control bit information is '11', setting the operation voltage signal A to be 0 and the operation voltage signal B to be 1 for negating the operation bit information; otherwise, setting the operation voltage signal A to be 1 and setting the operation voltage signal B to be 0;

s32, inputting corresponding operating voltage signals on the bit line and the word line where the operating bit memristor is located according to the voltage direction signals;

And S33, applying corresponding operating voltages on the bit line and the word line where the operating bit memristor is located according to the value of the operating voltage signal, and completing the writing of the operating bit information.

Further preferably, when the operating voltage signal takes a value of 0, an operating voltage of 0V is applied; when the operating voltage signal takes a value of 1, an operating voltage V1 is applied, where the operating voltage V1 is a voltage that causes the operating bit memristor to change from the other state to the fourth state, and the operating voltage V1 is greater than the operating voltage V2.

further preferably, the method for respectively inputting the corresponding operating voltage signals to the bit line and the word line where the control bit memristor or the operating bit memristor is located according to the voltage direction signal includes:

(1) when the voltage direction signal is 0, inputting an operation voltage signal A on a bit line where the control bit memristor or the operation bit memristor is located, and inputting an operation voltage signal B on a word line where the control bit memristor or the operation bit memristor is located;

(2) When the voltage direction signal is 1, an operating voltage signal a is input to a word line where the control bit memristor or the operating bit memristor is located, and an operating voltage signal B is input to a bit line where the control bit memristor the operating bit memristor is located.

Through the technical scheme, compared with the prior art, the invention has the following beneficial effects:

1. the invention provides a Toffoli gate circuit, which consists of a control bit memristor and an operation bit memristor, wherein the condition of the memristor is changed by controlling the voltage values input at two ends of the memristor by utilizing the characteristic that the memristor has multiple resistance states under different operation voltages, the voltage signal is used as input, the resistance state is used as output, the Toffoli reversible logic function can be realized by only adopting two memristors, the circuit complexity is lower, and the occupied area of the circuit is smaller.

2. The invention provides a Toffoli gate circuit operation method, which is characterized in that different control signals are respectively input on a word line and a bit line where a control bit memristor and an operation bit memristor are positioned to control voltages input at two ends of the memristor so as to change the state of the memristor, and further control bit information and operation bit information are respectively stored. Because the memristor has the characteristic of non-volatility, after the logic function is completed, the logic output is directly stored in the memristor, and extra data transmission and storage are not needed, so that the power consumption is greatly reduced, and the time delay is reduced.

drawings

FIG. 1 is a Toffoli gate circuit provided by the present invention;

FIG. 2 is a diagram illustrating the input/output relationship of Toffoli gate circuits provided by the present invention;

FIG. 3 is a method of operating a Toffoli gate circuit according to the present invention;

FIG. 4 is a diagram illustrating control bit information writing according to an embodiment of the present invention; wherein, fig. (a) is a schematic diagram of writing the control bit information "00" provided by the embodiment of the present invention, fig. (b) is a schematic diagram of writing the control bit information "01" provided by the embodiment of the present invention, fig. (c) is a schematic diagram of writing the control bit information "10" provided by the embodiment of the present invention, and fig. (d) is a schematic diagram of writing the control bit information "11" provided by the embodiment of the present invention;

FIG. 5 is a schematic diagram illustrating writing of operation bit information according to embodiment 2 of the present invention; wherein, fig. (a) is a schematic diagram of writing operation bit information "0" provided in embodiment 2 of the present invention, and fig. (b) is a schematic diagram of writing operation bit information "1" provided in embodiment 2 of the present invention;

FIG. 6 is a schematic diagram illustrating writing of operation bit information according to embodiment 3 of the present invention; fig. (a) is a schematic diagram of writing operation bit information "0" provided in embodiment 3 of the present invention, and fig. (b) is a schematic diagram of writing operation bit information "1" provided in embodiment 3 of the present invention.

1: control bit memristor 2: operation position memristor

11: array word line 12: array first bit line

22: second bit line of array

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In order to achieve the above object, the present invention provides a toffil gate circuit, as shown in fig. 1, which includes a control bit memristor 1, an operation bit memristor 2, and a controller 3; the anodes of the control bit memristor 1 and the operation bit memristor 2 are connected to the array word line 11, the cathode of the control bit memristor 1 is connected to the first bit line 12 of the array, the cathode of the operation bit memristor 2 is connected to the second bit line 22 of the array, and the controller 3 is connected to the sub-line and the bit line where the control bit memristor 1 and the operation bit memristor 2 are located respectively.

the control bit memristor 1 is used for storing two-bit control bit information by changing the resistance state of the control bit memristor according to the voltage input by the controller; specifically, the control bit memristor comprises a first state, a second state, a third state and a fourth state, which are respectively used for representing two-bit control bit information "00", "01", "10" and "11"; the first state and the fourth state of the control bit memristor respectively correspond to the highest resistance state and the lowest resistance state of the control bit memristor; the second state and the third state of the control bit memristor are both intermediate resistance states of the control bit memristor.

the operation bit memristor 2 is used for changing the resistance state of the operation bit memristor according to the voltage input by the controller so as to store one bit of operation bit information. Specifically, the operation bit memristor comprises a first state and a fourth state which are respectively used for representing one bit of operation bit information of '0' and '1', and the first state and the fourth state of the operation bit memristor respectively correspond to the highest resistance state and the lowest resistance state of the operation bit memristor.

specifically, the state of the memristor is changed by applying different operating voltages between the positive and negative electrodes of the control bit memristor or the operating bit memristor. When current flows from the anode to the cathode of the memristor, the resistance value of the memristor becomes low, and after the resistance value is reduced to a certain resistance value, the resistance value is not influenced by the forward current any more, and the resistance value is the lowest resistance value of the memristor; when current flows from the negative electrode to the positive electrode, the resistance value of the memristor becomes high, and after the resistance value is increased to a certain resistance value, the memristor is not influenced by reverse current any more, and the resistance value is the highest resistance value of the memristor. By controlling the voltage between the anode and the cathode of the memristor, the memristor can be switched between the lowest resistance value and the highest resistance value, and the intermediate resistance value which is higher than the lowest resistance value and lower than the highest resistance value is included. The control bit memristor and the operation bit memristor are resistance state gradual change type memristors, and very multi-stage intermediate resistance state changes can be achieved by continuously applying very small voltage pulses including positive and negative voltage pulses. In particular, although the memristor may be brought to a very large number of intermediate resistance states by voltage trimming the memristor, the excessive intermediate resistance states may cause difficulty in effectively distinguishing between adjacent resistance states. Therefore, only two intermediate resistance states are selected as the second state and the third state of the control bit memristor, and the first state and the fourth state of the control bit memristor and the operation bit memristor respectively correspond to the highest resistance state and the lowest resistance state.

the controller 3 is used for respectively controlling the voltages on the word lines and the bit lines where the control bit memristor 1 and the operation bit memristor 2 are located according to the logic operation rule of the Toffoli gate circuit.

specifically, fig. 2 shows the input-output corresponding relationship of the toffil gate circuit. The first two bits of information are used as control bit information, and the third bit of information is used as operation bit information. When the control bit information is not "11", the operation bit information remains unchanged; when the control bit information is "11", the operation bit information is inverted. The input and output are in one-to-one correspondence, and the input information at the position can be reversely deduced by the logic output result.

In another aspect of the present invention, a method for operating a toffil gate circuit is provided, as shown in fig. 3, including the steps of:

S1, dividing the three-bit input information into two-bit control bit information and one-bit operation bit information;

S2, writing control bit information into the control bit memristor according to the control signal;

s3, if the control bit information is '11', inverting the operation bit information and writing the operation bit information into the operation bit memristor according to the control signal; otherwise, directly writing the operation bit information into the operation bit memristor according to the control signal;

S4, reading the states of the control bit memristor and the operation bit memristor at the moment, namely the result of Toffoli reversible logic operation.

specifically, the control signal includes an initialization signal, a voltage direction signal, and an operation voltage signal, which are respectively taken as 0 or 1, wherein the operation voltage signal includes an operation voltage signal a and an operation voltage signal B; the initialization signal is used for controlling the initialization state of the memristor; the voltage direction signal is used for controlling the direction of the voltage applied across the memristor; the operating voltage signal is used to control the value of the input voltage. By applying different control signals to the word line and the bit line where the control bit memristor or the operation bit memristor is respectively located, information can be written by changing the resistance state of the control bit memristor the operation bit memristor.

Specifically, the method for writing the control bit information in the control bit memristor in step S2 includes the following steps:

S21, initializing the control bit memristor according to the initialization signal; specifically, when the initialization signal W is 0, the memristor is initialized to the first state 00; when the initialization signal W is 1, the memristor is initialized to a fourth state "11";

S22, setting the operation voltage signal A to be 1 and setting the operation voltage signal B to be 0;

S23, respectively inputting corresponding operating voltage signals on the bit line and the word line where the control bit memristor is located according to the voltage direction signal;

Specifically, when the voltage direction signal C is equal to 0, when the voltage direction signal C is 0, the operating voltage signal a is input to the bit line where the control bit memristor is located, and the operating voltage signal B is input to the word line where the control bit memristor is located; when the voltage direction signal is 1, an operating voltage signal a is input to a word line where the control bit memristor is located, and an operating voltage signal B is input to the control bit memristor or a bit line where the operating bit memristor is located.

And S24, applying corresponding operating voltages on the bit line and the word line where the control bit memristor is located according to the value of the input operating voltage signal, and completing the writing of the control bit information.

Specifically, corresponding operating voltages are respectively applied to a bit line and a word line where the control bit memristor is located according to the value of an input operating voltage signal, so that the state of the control bit memristor is changed to store control bit information; specifically, when the operating voltage signal (a or B) takes a value of 0, an operating voltage of 0V is applied, i.e., grounded; when the operating voltage signal (a or B) takes a value of 1, an operating voltage V2 is applied, where the operating voltage V2 is a voltage that causes the control bit memristor to change from the first state to the second state. Specifically, when the voltage drop across the control bit memristor is V2, the memristor is changed from the first state to the second state, and since the two-bit control bit information values corresponding to the second state and the third state are opposite, when the voltage drop across the control bit memristor is-V2, the memristor is changed from the fourth state to the third state. In particular, with TiN/TaO_x/HfAl_yO_xFor example, if the control bit memristor is TiN/TaO_x/HfAl_yO_xthe resistance value of the/TiN memristor is larger than 10k ohms in the first state, is between 5 and 10k ohms in the second state, is between 2.5 and 5k ohms in the third state, and is lower than 2.5k ohms in the fourth state.