JPS6398220A - Ternary logical operation circuit device - Google Patents

Abstract

PURPOSE:To execute ternary logical operation with simple a logic circuit constitution, by coupling superconducting elements in a logic circuit with a controlled current supplying line. CONSTITUTION:The ternary logical operation is executed by coupling a (p) circuit 10 which generates a positive voltage applying state, with an (n) circuit 20 which generates a negative voltage applying state, with the controlled current supplying line, connecting a load resistor to its midpoint, and outputting three kinds of voltage applying states of positive, 0, and negative, to the load resistor. The (p) circuit 10 and the (n) circuit 20 have almost the same constitution, and the (p) circuit 10 is provided with a serial branch of two inductances LP1 and LP2 connected to a controlled current input terminal 30, the serial branch of two inductances LP3 and LP4 connected to an offset current input terminal 31, and a Josephson circuit (superconduction circuit element).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an arithmetic circuit device that performs three-value logic operations using superconducting material elements such as Josephson elements.

(Prior Art) Three-valued logic systems in which logic variables have three truth values have been widely studied. This ternary logic system has simplified hardware compared to the traditional binary system.
It achieves various advantages such as reducing the area, increasing storage density by increasing the number of information levels in particular, and shortening calculation time and propagation delay by reducing the number of stages. be able to.

On the other hand, logic arithmetic circuit devices having superconducting elements such as Josephson elements have been put into practical use as tricycle logic arithmetic circuit devices. FIG. 6 shows a conventional arithmetic circuit having a Josephson element. Two inductances L1 on control line 1
and L2 are connected in series, and two inductances L3 and L4 are magnetically coupled to these inductances L and L2. A damping resistor R1 for preventing resonance development is connected in parallel to the series branches of the inductances L3 and L4, and the series branches of two Josephson elements J1 and J2 are connected in parallel, and the Josephson element JI
Ground the connection point between and J2. Inductance 3
A bias line 2 is connected to the connection point between and L4, and this bias line 2 is grounded via a load resistor RL.

FIG. 7 is a diagram showing the dark value characteristics of the Josephson element of the arithmetic circuit shown in FIG. The horizontal axis shows the control current 1c, and the vertical axis shows the bias current.

Outside the dark value line shown with hatching, the Josephson element is in a voltage state (normal conduction state), and inside it is in a superconductivity state. Therefore, as shown in Fig. 7, the bias current (2) is fixed and the control current is adjusted. By changing , the Josephson device switches between a superconducting state and a voltage state. On the other hand, at both ends of the load resistor R5, when the Josephson element is in a superconducting state, it has a zero potential, and when it is in a voltage state, it generates a predetermined potential. Therefore, the control current Ic is switched so that the element switches between the superconducting state and the voltage state, and it is set as "1" when the Josephson element is in the voltage state, and as 0 when it is in the superconducting state, while the load If the value is 1 when a potential difference occurs between both ends of the resistor RL, and the value is 0 when the potential is zero, an And operation is achieved.

(Problems to be Solved by the Invention) The arithmetic circuit having the Josephson element described above can achieve complex dark values and is advantageous in configuring a multivalued logic system. However, it has the disadvantage that only two values corresponding to "0" and "1" can be taken as voltage values, and therefore a three-value logic circuit cannot be constructed. Furthermore, since the dark value characteristic is regular, there is a disadvantage that the circuit configuration becomes complicated in order to express a unique function.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to eliminate the above-mentioned drawbacks and provide an arithmetic circuit having a superconducting element that can perform three-value logic operations at high speed and with low power consumption.

(Means and effects for solving the problem) A three-value logic operation circuit device according to the present invention includes at least one superconducting element that switches between a superconducting state and a normal conducting state according to dark value characteristics. A first and a second circuit having the above superconducting circuit elements.
Each superconducting circuit element of the first arithmetic circuit and each superconducting circuit element of the second arithmetic circuit are connected by a control current supply line, and three Any one of the control currents is supplied to the control current supply line to output a superconducting state or a voltage state from the first and second arithmetic circuits, and the output of the first and second arithmetic circuits is The present invention is characterized in that it is configured to output any one of three logical values based on the following.

In this way, since each superconducting circuit element of the first and second arithmetic circuits is connected by a control current supply line, any one of the three control currents can be applied to each superconducting circuit element. By supplying the superconducting state or the voltage state, the first and second arithmetic circuits can output a superconducting state or a voltage state according to the arithmetic command, and a three-valued output is formed based on these outputs.

As a result, ternary logic operations can be performed with a simple circuit configuration.

(Embodiment) FIG. 1 is a circuit diagram showing the configuration of an embodiment of an arithmetic circuit that performs three-value logic operations according to the present invention. In this example, a three-value logic operation circuit device that performs a single negation operation will be described. In the present invention, the p-circuit 10 that generates a positive voltage state and the n-circuit 20 that generates a negative voltage state are connected by a control current supply line, a load resistor is connected to the midpoint of the line, and a positive voltage, O5 is connected to the load resistor. It outputs three types of negative voltage states and executes three-value logic operations. The p-circuit 10 and the n-circuit 20 have almost the same configuration, and the p-circuit 10 is connected to a series branch of two inductances Lpl+Lpz connected to a control current input terminal 30 and an offset current input terminal 31. It has two series branches of inductances Lp3+Lp4 and a Josephson circuit (superconducting circuit element). The Josephson circuit has two inductances L□s
A damping resistor R3 is connected in parallel to the series branch of Lp&, and the series branches of two Josephson elements J, . . . Jt are further connected in parallel. The signal source and the Josephson circuit are connected by inductively coupling the inductance Lp++ Lglt+ LP31L, 4 on the signal source side and the inductance L R5+L, 6 on the Josephson circuit side. Further, the bias current input terminal 33 is connected to the connection point between the inductances LpS and Lp& of the Josephson circuit to supply a positive bias current element (2). The bias current +18 and the bias current -2 on the n circuit side, which will be described later, are selected to values that cause the critical current to vary cyclically.

The n-circuit 20 also has two series branches of inductances Lnl+Ln2 and two inductances. 3+ L114
It has a series branch of , and a Josephson circuit. The Josephson circuit has a configuration in which a damping resistor R2 is connected in parallel to a series branch of two inductances LnS+Ln&, and a series branch of two Josephson elements J:l+Ja is connected in parallel. Further, the bias current input terminal 34 is connected to the connection point between the Josephson elements J and J4 to supply a negative bias current -■. Connect the series branches of the two inductances Lllll l,, 2 of the 9 circuits to the series branches of the inductances LRII LR2 of the n circuit,
The other end of the series branch of L+11+L11□ is grounded to supply the control current ■8 to the 9 circuit and the n circuit, respectively. In addition, the series branches of the inductance Lp3+Lp4 of 9 circuits are made into the inductance of n circuits. .

It is connected to the series branch of Ln4, and the other end of the series branch of Lnl+Ln4 is grounded to supply offset currents to the n-circuit 10 and the n-circuit 20, respectively.

Note that the directions in which the control current 8 and the offset current Toff flow in the 9th circuit and the n circuit are set to be opposite to each other in the 9th circuit and the n circuit. Therefore, for example, if a positive control current or offset current flows in 9 circuits, a negative control current or offset current flows in 9 circuits, and 9
When a negative control current or offset current flows in the circuit n
A positive control current or offset current flows through the circuit. 9
Bias current input terminal 33 of the circuit is connected to two resistors R3+
Bias input terminal 34 of the n circuit via the series branch of R4
Also, a load inductance LL and a load resistance RL are connected in series to the connection point of the resistors R3 and R4, and the load resistance 1? Ground the other end of L. R3 and R4 function to prevent current from flowing to the load side when the Josephson element is in a superconducting state. Furthermore, the connection point between the Josephson elements J1 and J2 of the n-circuit 10 is connected to the connection point between the inductances L*S and Ln& of the n-circuit 20, and is also grounded. With this configuration, the Josephson element J of the n circuit 10, and the Josephson element J2 of the n circuit 20,
and J4 both become superconducting, the voltage across the load resistor RL becomes zero, and the Josephson element J of the n circuit 10
, and J2 are in a voltage state and the Josephson elements J3 and J4 of the n circuit 20 are in a superconducting state, a positive voltage is generated in the load resistor RL, and the Josephson elements J and J2 of the 9 circuits are in a superconducting state and the Josephson elements J3 and J4 of the n circuit 20 are in a superconducting state. When the sensor elements J3 and J4 enter a voltage state, a negative voltage is generated across the load resistor Rt.

FIGS. 2a and 2b are diagrams showing the dark value characteristics of each Josephson element of the n-circuit 10 and the n-circuit 20. A positive offset current ■ is applied to the n circuit 10. ff and a negative offset current -Ioff is supplied to the n circuit 20, so 9
The operating point of the circuit is fixed at point A, and the operating point of the n circuit is fixed at point D. Therefore, the control current 1. When is zero, the Josephson elements of nine circuits are in a voltage state, the Josephson elements of n circuits are in a superconducting state, and a positive voltage is generated in the load resistor RL. Next, when positive control current ■8 is supplied, 9
The operating point of the circuit moves to point B, and the operating point of the n circuit moves to point E. Therefore, the Josephson elements of nine circuits are in a superconducting state, the Josephson elements of n circuits are in a voltage state, and the voltage of the load resistor RL becomes negative. Furthermore, when a negative control current I is supplied, the operating point of the 9 circuits moves to the 0 point,
The operating point of the n circuit moves to point F. Therefore, both the 9-circuit and n-circuit Josephson elements become superconducting, and the voltage across the load resistor RL becomes zero. Control current zero, positive.

Each negative state is O+ + 1. -1, load resistance RL
If the zero, positive, and negative voltage states of are set to 0+ +1+ 1, the truth table shown in Table 1 is obtained, and the logical operation of -multiple negation can be executed.

Table 1 Regarding the negative logical operation, the negative operation of the truth table shown in Table 2 can be performed by using the arithmetic circuit shown in Figure 1 and setting the offset current and control current as shown in Figure 3. can.

Table 2 Next, an example of performing a ternary OR operation will be described. Three-value OR operation uses two control currents ■8 and I7, and generates an output according to the truth table shown in Table 3 for a three-value combination of control currents Ix and Iv of 1,0°1. achieved.

Table 3 This operation shows that the output of the two circuits and the N circuit of the present invention is 4 for the combination of control currents Ix and IY of 3 values of 1.0.1.
This is achieved by obtaining the outputs shown in the truth tables of tables a and b, respectively.

Table 4 FIG. 4 shows a circuit configuration for executing this three-value OR operation.

In this three-value OR circuit, two Josephson circuit elements (superconducting circuit elements) are used for the 9 circuits, one Josephson circuit element is used for the n circuit, and the circuit shown in Figure 1 is used for the load section. . The same members as those used in FIG. 1 will be described with the same reference numerals. One end of the series branch of the two inductances LIO+ Ll+ magnetically coupled to the two inductances of the first Josephson circuit element 40 is connected to the input terminal 41 of the control current IX, and the other end is connected to the Josephson circuit element of the n circuit 20. Magnetically coupled with the inductance of the circuit element 2
Inductance Lllll is connected to the series branch of Ln2. In addition, two inductances L magnetically coupled to the two inductances of the second Josephson circuit element 42
One end of the series branch of I2+ L13 is connected to the input terminal 43 of the control current Iy, and the other end is connected to the series branch of two inductances LF13+ LP11 magnetically coupled to the inductance of the Josephson circuit element of the n-circuit 20. . As a result, nine Josephson circuit elements and n Josephson circuit elements are coupled by the control current supply line. Furthermore, the bias current input terminal 33 of the p-circuit 10 is connected to the connection point of the two inductances LI1+L+s, and these inductances LI4. Q control in which one end of the series branch of LI5 is connected to the connection point of the two inductances of the first Josephson circuit element 40, and the other end is connected to the connection point of the two inductances of the second Josephson circuit element 42. When either current 8 or I7 becomes a positive control current, either Josephson circuit element 40 or 42 switches to a voltage state, and then the pixel becomes a voltage state and current is supplied to the load side. . On the other hand,
When both or only one of the control currents 18 and 7 becomes a negative control current, these Josephson circuit elements 40 and 42
is maintained in a superconducting state due to the asymmetric threshold characteristics of
The flow does not flow to the load side, and the arithmetic operation shown in the truth table of result table 4a is executed. A three-value OR circuit is achieved by nine circuits that perform such operations and the n circuits shown in FIG.

This OR operation will be explained with reference to the dark value characteristic diagrams shown in FIG. 5a''-c. FIG. FIG. 5C shows the dark value operating characteristics of the second Josephson circuit element 42.
represents the dark value operating characteristic of an n-circuit Josephson circuit element. When the control currents Ix and ry are both O, the operating points of the 9-circuit Josephson circuit elements 40 and 42 and the operating points of the n-circuit Josephson circuit element are determined at points 50, 60, and 70, respectively.

When the control currents 8 and IY switch to T from this state, the operating points 50.60 and 70 change to the operating points 51.61 and 7.
1 respectively. When bias currents ■3 and -■ are supplied to the 9 circuit and the n circuit, respectively, each operating point becomes 5.
2.62 and 72, respectively, nine Josephson circuit elements 40 and 42 become superconducting and n Josephson circuit elements switch to a voltage state, resulting in an output of T. When the control current becomes Ix=O, Iv=T and the bias currents ■ and −■ are supplied, the operating points of the Josephson circuit element 40, 42 and the Josephson circuit element of the n circuit are respectively 539 points. 62 and point 73 (note that since the control current acts on the Josephson circuit element of n circuits as much as 1, the control current is at the position of A with respect to point 72). As a result, all three Josephson circuit elements become superconducting and therefore output a zero.

When the control current becomes ``1.Iy=lower'' and the bias currents I, l, and -I are respectively supplied, the operating points become points 549, 62, and 74, and as a result, the two circuits are in the voltage state. Therefore, the n circuit enters the superconducting state, and therefore outputs 1. When the control current becomes Ix = 1. IY = O, the operating points become points 541, 63, and 75, respectively, and as a result, the two circuits become voltage state, the n circuit becomes a superconducting state, and therefore 1 is output.The control current becomes Ix=1
+ When h=t, the respective operating points are points 541, 64, and 76, and as a result, two circuits are in a voltage state and n circuits are in a superconducting state, so that 1 is output. Furthermore, when the control currents IX=O and Iv=0, both the 9th circuit and the nth circuit become superconducting, and therefore, 0 is output.

By appropriately selecting the two control currents lx and Iy and the bias currents Is and Is with respect to the threshold characteristics in this manner, the three-value OR operation shown in Table 3 can be performed with a simple circuit configuration.

Note that the ternary AND operation can also be performed by the same operation as the ternary OR circuit.

(Effects of the Invention) As explained above, according to the present invention, nine Josephson circuit elements (superconducting circuit elements) and n Josephson circuit elements are connected by a control current supply line, and arithmetic commands are Accordingly, one of the three control currents is supplied to each Josephson circuit element, and the superconducting state or voltage state is output from the 9 circuits and the n circuit, so the circuit structure is simple. Various ternary logic operations can be performed.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of an example of a ternary logic operation circuit device that executes a logical operation of single negation, and FIG.
A diagram showing the dark value characteristics of a value logic operation circuit. Figure 3 is a diagram showing the dark value characteristics when performing a negative logic operation. Figure 4 is a 3-value logic operation circuit device that performs a 3-value OR logic operation. A circuit diagram showing the configuration of an example, FIG. 5 is a diagram showing the dark value characteristics of the arithmetic circuit device shown in FIG. 4, and FIG. 6 shows the configuration of a conventional binary logic arithmetic circuit having a superconducting element. Circuit Diagram FIG. 7 is a diagram showing dark value characteristics of the binary logic operation circuit of FIG. 6. 10...9 circuits 20...n circuits J,,
J,, J,, J4... Josephson element 30.
...Control signal input terminals 31, 33.34...Offcent current input terminals 40,
42...Josephson circuit elements 41, 43...Control signal input terminals Fig. 2 - 1% control current 9JA) - Fig. 3 a □ Control current □ Fig. 5 b -Electrolyte IX--electrode Zy→-IX, IY-

Claims (1)

[Claims] 1. A first and a second arithmetic circuit having at least one superconducting circuit element including a superconducting element that switches between a superconducting state and a normal conducting state according to threshold characteristics; Each superconducting circuit element of the arithmetic circuit and each superconducting circuit element of the second arithmetic circuit are connected by a control current supply line, and any one of three control currents having different values is controlled according to an arithmetic command. Supplying current to the control current supply line to output a superconducting state or a voltage state from the first and second arithmetic circuits, and determining one of three logical values based on the outputs of the first and second arithmetic circuits. A ternary logic operation circuit device characterized in that it is configured to output one.