阅读说明：本技术 一种可编程忆阻器逻辑电路 (Programmable memristor logic circuit ) 是由 林弥 王旭亮 李路平 陈俊杰 韩琪 罗文瑶 于 2021-01-11 设计创作，主要内容包括：本发明公开了一种可编程忆阻器逻辑电路,包括第一阈值型忆阻器Ma、第二阈值型忆阻器Mb、第三阈值型忆阻器Mc、第四阈值型忆阻器Md、第一NMOS晶体管M1、第二NMOS晶体管M2、第三NMOS晶体管M3、第四NMOS晶体管M4、第五NMOS晶体管M5、第六NMOS晶体管M6、第一电阻R1和第二电阻R2、第一使能端S1、第二使能端S2和第三使能端S3。该电路通过调节使能端来实现在同一电路中完成“与”、“或”、“非”逻辑运算的功能,电路结构简单,功能调节灵活,对基于忆阻器的数字逻辑电路的研究具有重大意义。(The invention discloses a programmable memristor logic circuit which comprises a first threshold memristor Ma, a second threshold memristor Mb, a third threshold memristor Mc, a fourth threshold memristor Md, a first NMOS transistor M1, a second NMOS transistor M2, a third NMOS transistor M3, a fourth NMOS transistor M4, a fifth NMOS transistor M5, a sixth NMOS transistor M6, a first resistor R1, a second resistor R2, a first enabling end S1, a second enabling end S2 and a third enabling end S3. The circuit realizes the function of completing AND, OR and NOT logical operation in the same circuit by adjusting the enabling end, has simple structure and flexible function adjustment, and has great significance for the research of the digital logic circuit based on the memristor.)

1. A programmable memristor logic circuit is characterized by at least comprising a first threshold type memristor Ma, a second threshold type memristor Mb, a third threshold type memristor Mc, a fourth threshold type memristor Md, a first NMOS transistor M1, a second NMOS transistor M2, a third NMOS transistor M3, a fourth NMOS transistor M4, a fifth NMOS transistor M5, a sixth NMOS transistor M6, a first resistor R1 and a second resistor R2, wherein the states of the NMOS transistors and the resistance states of the threshold type memristors are controlled by arranging a first enabling terminal S1, a second enabling terminal S2 and a third enabling terminal S3, and various logic operations are further completed in the same circuit;

wherein the positive terminal of the first threshold type memristor Ma is connected with the drain of the first NMOS transistor M1; the positive end of the second threshold type memristor Mb is connected with the drain electrode of the second NMOS transistor M2, and the negative ends of the Ma and the Mb are both connected with the clock signal V_CLK(ii) a The negative end of the fourth threshold type memristor Md is connected with the drain of the fifth NMOS transistor M5, and the positive end of the Md is connected with the clock signal V_CLK(ii) a The negative end of the third threshold type memristor Mc is connected with the drain electrode of the third NMOS transistor M3, and the positive end of the Mc is connected with the source electrode of the second NMOS transistor M2;

the gate of the first NMOS transistor M1 is connected to the signal input terminal a, and the source of the first NMOS transistor M1 is connected to one end of the first resistor R1; the gate of the second NMOS transistor M2 is connected to the signal input terminal B; the gate of the third NMOS transistor M3 is connected to the signal input terminal C, and the source of the third NMOS transistor M3 is connected to ground; the drain of the fourth NMOS transistor M4 is connected to the other end of the first resistor R1, the gate of M4 is connected to the first enable terminal S1, and the source of M4 is connected to ground; the gate of the fifth NMOS transistor M5 is connected to the second enable terminal S2, and the source of M5 is connected to one end of the second resistor R2; the drain of the sixth NMOS transistor M6 is connected to the other end of the second resistor R2, the gate of M6 is connected to the third enable terminal S3, and the source of M6 is connected to ground;

one end of the first resistor R1 is connected with the source electrode of the first NMOS transistor M1, and the other end of the first resistor R1 is connected with the drain electrode of the fourth NMOS transistor M4; one end of the second resistor R2 is connected to the source of the fifth NMOS transistor M5, and the other end of the second resistor R2 is connected to the drain of the sixth NMOS transistor M6.

2. The programmable memristor logic circuit of claim 1, wherein the first enable terminal S1, the second enable terminal S2, and the third enable terminal S3 are all active high.

3. The programmable memristor logic circuit of claim 1, wherein the first resistance R1 and the second resistance R2 satisfy: 1/2R_ON<R1<R_ON，R_ON<R2<R_OFF，R_ON<<R_OFF，R1<<R_OFF。

Technical Field

The invention belongs to the technical field of circuit design, relates to a programmable memristor logic circuit, and particularly relates to a circuit for realizing multiple logic operation functions in the same circuit.

Background

The memristor is a two-port circuit device representing the relation between magnetic flux and electric charge, is a nonvolatile resistor, and has huge research potential in the directions of nonvolatile memories, large-scale integrated circuits, artificial neural networks, artificial intelligence, digital logic circuits and the like because of the nanometer size, the fast erasing speed, the memory characteristic, the switching characteristic and the good CMOS compatibility. The threshold type memristor has unique high and low resistance value states and definite threshold voltages, which correspond to '0' and '1' in digital logic very appropriately, and is convenient to adjust.

The research of digital logic circuits based on memristors is relatively extensive nowadays. However, general memristive digital logic circuits can only realize one logic operation function in the same circuit, are complex in application, require a large number of circuit elements when realizing various logic operation functions, and occupy more circuit area. Therefore, the invention relates to a programmable memristor logic circuit, in particular to a circuit for realizing multiple logic operation functions in the same circuit.

Disclosure of Invention

Aiming at the problems in the prior art and the research cost, the invention provides the programmable memristor logic circuit with the novel structure, the state of the MOS transistor and the resistance state of the threshold memristor are controlled by the enable terminal of the circuit, so that the same circuit has multiple logic operation functions, and a new application field and a new design idea are provided for the memristor logic circuit.

The technical scheme adopted by the invention for solving the technical problem is as follows: a programmable memristor logic circuit comprises four threshold-type memristors, six NMOS transistors and two resistors. Wherein the positive terminal of the first threshold type memristor Ma is connected to the drain of the first NMOS transistor M1; the positive end of the second threshold type memristor Mb is connected with the drain electrode of the second NMOS transistor M2, and the negative ends of the Ma and the Mb are both connected with the clock signal V_CLK(ii) a The negative end of the fourth threshold type memristor Md is connected with the drain of the fifth NMOS transistor M5, and the positive end of the Md is connected with the clock signal V_CLK(ii) a The gate of the first NMOS transistor M1 is connected to the signal input terminal a, and the source of the first NMOS transistor M1 is connected to one end of the first resistor R1; the gate of the second NMOS transistor M2 is connected to the signal input terminal B, and the source of the second NMOS transistor M2 is connected toThe positive end of the third threshold type memristor Mc is connected; the gate of the fifth NMOS transistor M5 is connected to the second enable terminal S2, and the source of M5 is connected to one end of the second resistor R2; the drain of the fourth NMOS transistor M4 is connected to the other end of the first resistor R1, and the gate of M4 is connected to the first enable terminal S1; the drain of the third NMOS transistor M3 is connected to the negative terminal of the third threshold-type memristor Mc, and the gate of M3 is connected to the signal input terminal C; the drain of the sixth NMOS transistor M6 is connected to the other end of the second resistor R2, the gate of M6 is connected to the third enable terminal S3, and the sources of M3, M4, and M6 are all connected to ground; output end V_OUTIs a connection point of the first NMOS transistor M1 and the first resistor R1, a connection point of the second NMOS transistor M2 and the third threshold memristor Mc, and a connection point of the fifth NMOS transistor M5 and the second resistor R2.

As a further improvement, the first enable terminal S1, the second enable terminal S2, and the third enable terminal S3 are all active high.

As a further improvement, the first resistor R1 and the second resistor R2 satisfy: 1/2R_ON<R1<R_ON，R_ON<R2<R_OFF，R_ON<<R_OFF，R1<<R_OFF。

Compared with the prior art, the programmable memristor logic circuit is designed. The circuit realizes the function of completing AND, OR and NOT logical operation in the same circuit by adjusting the enabling end, has simple structure and flexible function adjustment, and has great significance for the research of the digital logic circuit based on the memristor.

Drawings

FIG. 1 is a device schematic of a threshold-type memristor.

FIG. 2 is a current-voltage characteristic of a threshold-type memristor.

FIG. 3 is a schematic diagram of a programmable memristor logic circuit of the present disclosure.

FIG. 4 is a programmable memristor logic circuit simulation test diagram of the present disclosure.

Table 1 is a table of the logical relationship between the enable control terminal and the input and output signals of the present invention.

Detailed Description

The following describes an example of the present invention in detail with reference to the accompanying drawings.

Referring to fig. 1, a device schematic diagram of a threshold-type memristor is shown, fig. 2 is a current-voltage characteristic curve of the threshold-type memristor, and it can be seen from fig. 2 that when a signal exceeding a threshold voltage is applied to two ends of the threshold-type memristor, the resistance value is in a high resistance state R_OFFAnd a low resistance state R_ONThe switching characteristics and controllability are obvious.

The programmable memristor logic circuit is designed by utilizing the characteristics of the threshold type memristor, and is shown in fig. 3. S1, S2, S3 are enable control terminals, active high. A. B, C is a signal input terminal, V_CLKFor clock signals, V_OUTFor a signal output end, Ma, Mb, Mc and Md are all threshold type memristor models, and the initial states of the memristors are assumed to be high-resistance states R_OFFHigh resistance values R of the first, second and third threshold type memristors Ma, Mb and Mc_OFFEqual and lower than the high resistance value of the fourth threshold type memristor Md, M1, M2, M3, M4, M5, M6 are all NMOS transistors, and the resistances R1 and R2 are made to satisfy: 1/2R_ON<R1<R_ON，R_ON<R2<R_OFF，R_ON<<R_OFF，R1<<R_OFF. The state of the MOS transistor and the resistance state of the threshold memristor are controlled through the enable end, and the function of finishing various logic operations in the same circuit is achieved.

When V is_CLKAt low level, the circuit outputs V_OUTIs low level; when V is_CLKWhen high, the circuit outputs V_OUTKeeping the same; the following working states are all V_CLKAt the rising edge.

1. When the enable control terminal S1S2S3 is 100 and the input signal C is 1, the third NMOS transistor M3 and the fourth NMOS transistor M4 are in a conducting state and the resistance state of the third threshold memristor Mc remains in the high-resistance state R_OFFWithout change, the fifth NMOS transistor M5 and the sixth NMOS transistor M6 are in an off state.

(1) When in useWhen the input signal AB is 00, the first NMOS transistor M1 and the second NMOS transistor M2 are in an off state, and the output signal V is output_OUTIs logic 0;

(2) when the input signal AB is 01, the first NMOS transistor M1 is turned off, the second NMOS transistor M2 is turned on, and the second threshold memristor Mb is changed from the high-resistance state R_OFFConversion to the low-resistance state R_ONThe parallel branch of the third threshold type memristor Mc and the first resistor R1 and the second threshold type memristor Mb form a series voltage division circuit, because R1<<R_OFFAfter the third threshold type memristor Mc is connected with the first resistor R1 in parallel, the resistance value is approximately equal to R1, and the output signal V is_OUTIs logic 0;

(3) similarly, when the input signal AB is 10 and AB is 01, the second NMOS transistor M2 is turned off, the first NMOS transistor M1 is turned on, and the first threshold memristor Ma is converted into the low resistance state R_ONThe parallel branch of the third threshold type memristor Mc and the first resistor R1 and the first threshold type memristor Ma form a series voltage division circuit, and the output signal V_OUTIs logic 0;

(4) when the input signal AB is 11, since the first NMOS transistor M1 and the second NMOS transistor M2 are both in the on state, the resistance states of the first threshold type memristor Ma and the second threshold type memristor Mb are both converted into the low resistance state R_ONThe parallel branch of the first threshold type memristor Ma and the second threshold type memristor Mb and the parallel branch of the third threshold type memristor Mc and the first resistor R1 form a series voltage division circuit, because of 1/2R_ON<R1<R_ONOutput signal V_OUTIs a logic 1.

Therefore, when the enable control terminal S1S2S3 is equal to 100 and the signal C is equal to 1, the circuit implements an and logic operation function.

2. When the enable control terminal S1S2S3 is 011, the input signal C is 0, the third NMOS transistor M3 and the fourth NMOS transistor M4 are always in an off state, the fifth NMOS transistor M5 and the sixth NMOS transistor M6 are always in an on state, and the fourth threshold memristor Md always maintains the high-resistance state R_OFF。

(1) When the input signal AB is 00, the first NMOS transistor M1 and the second NMOS transistorM2 are all in the cut-off state, and the output is the second resistor R2 and the fourth threshold type memristor Md voltage division, because R2<R_OFFOutput signal V_OUTIs logic 0;

(2) when the input signal AB is 10, the first NMOS transistor M1 is in an on state, the second NMOS transistor M2 is in an off state, and the first threshold memristor Ma is converted into a low-resistance state R_ONThe parallel branch of the first and fourth threshold memristors Ma and Md and the second resistor R2 form a series voltage dividing circuit because R_ON<R2<R_OFFOutput signal V_OUTIs logic 1;

(3) when the input signal AB is 01 and AB is 10, the first NMOS transistor M1 is turned off, the second NMOS transistor M2 is turned on, and the second threshold memristor Mb is switched to the low resistance state R_ONThe parallel branch of the second threshold type memristor Mb and the fourth threshold type memristor Md and the second resistor R2 form a series voltage division circuit, and the output signal V_OUTIs logic 1;

(4) when the input signal AB is 11, the first NMOS transistor M1 and the second NMOS transistor M2 are both in an on state, and the first threshold type memristor Ma and the second threshold type memristor Mb are converted into a low resistance state R_ONThe parallel branch of the first threshold type memristor Ma, the second threshold type memristor Mb and the fourth threshold type memristor Md and the second resistor R2 form a series voltage division circuit, and the output signal V is_OUTIs a logic 1.

Therefore, when the enable control terminal S1S2S3 is 011 and the input signal C is 0, the circuit implements an or logic operation function.

3. When the enable control terminal S1S2S3 is 010 and the input signal AB is 00, the first NMOS transistor M1, the second NMOS transistor M2, the fourth NMOS transistor M4, and the sixth NMOS transistor M6 are turned off, and the fifth NMOS transistor M5 is turned on.

(1) When the input signal C is equal to 0, the third NMOS transistor M3 is turned off, the fifth NMOS transistor M5 is turned on, and the output signal V is output_OUTIs logic 1;

(2) when the input signal C is 1, the third NMOS transistor M3 and the fifth NMOS transistor M5 are in conductionIn an on state, the third threshold type memristor Mc and the fourth threshold type memristor Md are in a high resistance state R_OFFWhen the third threshold memristor Mc and the fourth threshold memristor Md form a series voltage-dividing circuit, and the high resistance value of the third threshold memristor Mc is lower than that of the fourth threshold memristor Md, the output signal V is output_OUTIs a logic 0.

Therefore, when the enable control terminal S1S2S3 is 010 and the input signal AB is 00, the circuit implements a not logical operation function.

The voltage drop between the source and the drain of the MOS tube is ignored in the above analysis.

In conclusion, when V is_CLKAt low level, the circuit outputs V_OUTIs low level; when V is_CLKWhen high, the circuit outputs V_OUTKeeping the same; when V is_CLKOn the rising edge: when the input signal C is equal to 1 and the enable control terminal S1S2S3 is equal to 100, the input signal A, B constitutes and logic; when the input signal C is equal to 0 and the enable control terminal S1S2S3 is equal to 011, the input signal A, B constitutes or logic; when the input signal AB is 00 and the enable control terminal S1S2S3 is 010, the input signal C constitutes not logic. The logical relationship between the enable control terminal and the input and output signals is shown in table 1. Different logic operation functions can be realized by selecting different enabling ends, and further the design of the programmable logic circuit is achieved.

TABLE 1 logical relationship between output signals

FIG. 4 shows the PSPICE simulation result of the programmable memristor logic circuit.

Definition V_CLKThe pulse signal has the amplitude of 5V and the frequency of 1 MHZ; defining the high resistance values of the memristors Ma, Mb and Mc to be 16K omega, and the high resistance value of the memristor Md to be 40K omegaThe threshold voltage of the resistor is about 2.6V, and the low resistance value is 1K omega; the first resistance value is 900 Ω, and the second resistance value is 11K Ω; the input signals A, B, C are each pulse signals having an amplitude of 5V. As can be seen from figure 4 of the drawings,

when the time is 0-4 mu s, the circuit realizes the AND logic operation function;

when the time is 4-8 mus, the circuit realizes the logical operation function of OR;

at 8-10 mus, the circuit realizes the 'not' logic operation function.

The above logics are all in accordance with the judgment of the digital logic circuit.

As can be seen from the simulation result of FIG. 4, the circuit can realize AND, OR, and NOT three logic operation functions under the control of the enable terminal, thereby realizing the function of the programmable circuit.

It should be appreciated by those skilled in the art that the above embodiments are only used for verifying the present invention, and are not to be construed as limiting the present invention, and that the changes and modifications of the above embodiments are within the scope of the present invention.