Three-valued logic function circuit
View Patent ↗There is provided a three-valued logic function circuit capable of remarkably reducing the kinds of basic circuits necessary for realizing all 3 3^2 =19683 kinds of two-variable three-valued logic function circuits, remarkably reducing asymmetry of the switching time, and improving an operation speed and symmetry of waveform of the logic function circuit. In a three-valued logic function circuit, three transfer gates T 1 , T 2 , and T 3 are turned on or off by one-variable three-valued logic function circuits C 1 , D 1 , C 3 and D 3 , according to three logic values −1, 0, and 1 constituting a first input a, to select outputs of three one-variable three-valued logic function circuits B 1 , B 2 , and B 3 connected to a second input b. The transfer gate T 2 is configured by parallel connection of a switch pair of serial connection of two n-type MOS transistors and a switch pair of serial connection of two p-type MOS transistors.
1. A three-valued logic function circuit that carries out a two-variable three-valued logic operation, the circuit comprising:
a first transfer gate that is turned on according to a first logic value of three logic values constituting a first input;
a second transfer gate that is configured by connecting a first switch pair of serial connection of two n-type MOS transistors and a second switch pair of serial connection of two p-type MOS transistors in parallel to each other, and that is turned on according to a second logic value of three logic values constituting the first input;
a third transfer gate that is turned on according to a third logic value of three logic values constituting the first input;
a first one-variable three-valued logic function circuit that is connected to one control terminal of two control terminals of the first transfer gate, and one control terminal of two control terminals of the first switch pair or the second switch pair constituting the second transfer gate, and that obtains a first output from the first input;
a second one-variable three-valued logic function circuit that is connected to the other control terminal of two control terminals of the first transfer gate, and one control terminal of two control terminals of the switch pair different from the switch pair connected to the first one-variable three-valued logic function circuit of the first switch pair or the second switch pair constituting the second transfer gate, and that obtains a second output complementarily symmetric with the first output from the first input;
a third one-variable three-valued logic function circuit that is connected to one control terminal of two control terminals of the third transfer gate, and the other control terminal of two control terminals of the same switch pair as the switch pair connected to the first one-variable three-valued logic function circuit of the first switch pair or the second switch pair constituting the second transfer gate, and that obtains a third output from the first input;
a fourth one-variable three-valued logic function circuit that is connected to the other control terminal of two control terminals of the third transfer gate, and the other control terminal of two control terminals of the same switch pair as the switch pair connected to the second one-variable three-valued logic function circuit of the first switch pair or the second switch pair constituting the second transfer gate, and that obtains a fourth output complementarily symmetric with the third output from the first input;
a fifth one-variable three-valued logic function circuit that is connected to an input terminal of the first transfer gate, and that obtains a fifth output according to a first logic value of three logic values constituting a second input;
a sixth one-variable three-valued logic function circuit that is connected to an input terminal of the second transfer gate, and that obtains a sixth output according to a second logic value of three logic values constituting the second input; and
a seventh one-variable three-valued logic function circuit that is connected to an input terminal of the third transfer gate, and that obtains a seventh output according to a third logic value of three logic values constituting the second input,
wherein output terminals of the first to third transfer gates are connected by Wired OR.
2. The three-valued logic function circuit according to claim 1 , wherein the first transfer gate is turned on according to a logic value −1 of three logic values −1, 0, and 1 constituting the first input,
the second transfer gate is turned on according to a logic value 0 of three logic values −1, 0, and 1 constituting the first input,
the third transfer gate is turned on according to a logic value 1 of three logic values −1, 0, and 1 constituting the first input,
the first one-variable three-valued logic function circuit obtains an output (1, −1, −1) from the first input (−1, 0, 1),
the second one-variable three-valued logic function circuit obtains an output (−1, 1, 1) from the first input (−1, 0, 1),
the third one-variable three-valued logic function circuit obtains an output (−1, −1, 1) from the first input (−1, 0, 1), and
the fourth one-variable three-valued logic function circuit obtains an output (1, 1, −1) from the first input (−1, 0, 1).
3. The three-valued logic function circuit according to claim 1 , further comprising, instead of the second one-variable three-valued logic function circuit, an inverter that is connected to the other control terminal of two control terminals of the first transfer gate, and the other control terminal of two control terminals of the same switch pair as the switch pair connected to the first one-variable three-valued logic function circuit of the first switch pair or the second switch pair constituting the second transfer gate, and that inverts an output of the first one-variable three-valued logic function circuit.
4. The three-valued logic function circuit according to claim 1 or 3 , further comprising, instead of the third one-variable three-valued logic function circuit, an inverter that is connected to one control terminal of two control terminals of the third transfer gate, and one control terminal of two control terminals of the switch pair different from the switch pair connected to the first one-variable three-valued logic function circuit of the first switch pair or the second switch pair constituting the second transfer gate, and that inverts an output of the fourth one-variable three-valued logic function circuit.
5. The three-valued logic function circuit according to any one of claims 1 to 3 , wherein each of the first to third transfer gates is formed of an enhancement n-type MOS transistor and an enhancement p-type MOS transistor,
the enhancement n-type MOS transistor has a positive threshold voltage smaller than a threshold voltage of a normal enhancement n-type transistor, and
the enhancement p-type MOS transistor has a negative threshold voltage smaller in absolute value than a threshold voltage of a normal enhancement p-type transistor.
6. The three-valued logic function circuit according to any one of claims 1 to 3 , wherein each of the fifth to seventh one-variable three-valued logic function circuit is any one of a first inverse circuit that obtains an output (0, −1, −1) from the second input (−1, 0, 1), a second inverse circuit that obtains an output (0, 0, −1) from the second input (−1, 0, 1), a third inverse circuit that obtains an output (1, −1, −1) from the second input (−1, 0, 1), a fourth inverse circuit that obtains an output (1, 0, −1) from the second input (−1, 0, 1), a fifth inverse circuit that obtains an output (1, 0, 0) from the second input (−1, 0, 1), a sixth inverse circuit that obtains an output (1, 1, −1) from the second input (−1, 0, 1), a seventh inverse circuit that obtains an output (1, 1, 0) from the second input (−1, 0, 1), a first non-inverse circuit that obtains an output (0, −1, 0) from the second input (−1, 0, 1), a second non-inverse circuit that obtains an output (0, −1, 1) from the second input (−1, 0, 1), a third non-inverse circuit that obtains an output (1, −1, 0) from the second input (−1, 0, 1), a fourth non-inverse circuit that obtains an output (1, −1, 1) from the second input (−1, 0, 1), a fifth non-inverse circuit that obtains an output (1, 0, 1) from the second input (−1, 0, 1), a first complementary symmetry circuit that obtains an output complementarily symmetric with the output of the first non-inverse circuit, a second complementary symmetry circuit that obtains an output complementarily symmetric with the output of the second non-inverse circuit, a third complementary symmetry circuit that obtains an output complementarily symmetric with the output of the third non-inverse circuit, a fourth complementary symmetry circuit that obtains an output complementarily symmetric with the output of the fourth non-inverse circuit, and a fifth complementary symmetry circuit that obtains an output complementarily symmetric with the output of the fifth non-inverse circuit.
7. The three-valued logic function circuit according to claim 6 , wherein the third non-inverse circuit has an enhancement p-type MOS transistor connected to a source logic value 0 having a negative threshold voltage smaller in absolute value than a threshold voltage of a normal enhancement p-type transistor,
the fifth non-inverse circuit has an enhancement n-type MOS transistor connected to a source logic value 0 having a positive threshold voltage smaller than a threshold voltage of a normal enhancement n-type transistor,
the second complementary symmetry circuit has an enhancement n-type MOS transistor connected to a source logic value 0 having a positive threshold voltage smaller than a threshold voltage of a normal enhancement n-type transistor, and
the fifth complementary symmetry circuit has an enhancement p-type MOS transistor connected to a source logic value 0 having a negative threshold voltage smaller in absolute value than a threshold voltage of a normal enhancement p-type transistor.
8. The three-valued logic function circuit according to claim 4 , wherein each of the first to third transfer gates is formed of an enhancement n-type MOS transistor and an enhancement p-type MOS transistor,
the enhancement n-type MOS transistor has a positive threshold voltage smaller than a threshold voltage of a normal enhancement n-type transistor, and
the enhancement p-type MOS transistor has a negative threshold voltage smaller in absolute value than a threshold voltage of a normal enhancement p-type transistor.
9. The three-valued logic function circuit according to claim 4 , wherein each of the fifth to seventh one-variable three-valued logic function circuit is any one of a first inverse circuit that obtains an output (0, −1, −1) from the second input (−1, 0, 1), a second inverse circuit that obtains an output (0, 0, −1) from the second input (−1, 0, 1), a third inverse circuit that obtains an output (1, −1, −1) from the second input (−1, 0, 1), a fourth inverse circuit that obtains an output (1, 0, −1) from the second input (−1, 0, 1), a fifth inverse circuit that obtains an output (1, 0, 0) from the second input (−1, 0, 1), a sixth inverse circuit that obtains an output (1, 1, −1) from the second input (−1, 0, 1), a seventh inverse circuit that obtains an output (1, 1, 0) from the second input (−1, 0, 1), a first non-inverse circuit that obtains an output (0, −1, 0) from the second input (−1, 0, 1), a second non-inverse circuit that obtains an output (0, −1, 1) from the second input (−1, 0, 1), a third non-inverse circuit that obtains an output (1, −1, 0) from the second input (−1, 0, 1), a fourth non-inverse circuit that obtains an output (1, −1, 1) from the second input (−1, 0, 1), a fifth non-inverse circuit that obtains an output (1, 0, 1) from the second input (−1, 0, 1), a first complementary symmetry circuit that obtains an output complementarily symmetric with the output of the first non-inverse circuit, a second complementary symmetry circuit that obtains an output complementarily symmetric with the output of the second non-inverse circuit, a third complementary symmetry circuit that obtains an output complementarily symmetric with the output of the third non-inverse circuit, a fourth complementary symmetry circuit that obtains an output complementarily symmetric with the output of the fourth non-inverse circuit, and a fifth complementary symmetry circuit that obtains an output complementarily symmetric with the output of the fifth non-inverse circuit.
10. The three-valued logic function circuit according to claim 5 , wherein each of the fifth to seventh one-variable three-valued logic function circuit is any one of a first inverse circuit that obtains an output (0, −1, −1) from the second input (−1, 0, 1), a second inverse circuit that obtains an output (0, 0, −1) from the second input (−1, 0, 1), a third inverse circuit that obtains an output (1, −1, −1) from the second input (−1, 0, 1), a fourth inverse circuit that obtains an output (1, 0, −1) from the second input (−1, 0, 1), a fifth inverse circuit that obtains an output (1, 0, 0) from the second input (−1, 0, 1), a sixth inverse circuit that obtains an output (1, 1, −1) from the second input (−1, 0, 1), a seventh inverse circuit that obtains an output (1, 1, 0) from the second input (−1, 0, 1), a first non-inverse circuit that obtains an output (0, −1, 0) from the second input (−1, 0, 1), a second non-inverse circuit that obtains an output (0, −1, 1) from the second input (−1, 0, 1), a third non-inverse circuit that obtains an output (1, −1, 0) from the second input (−1, 0, 1), a fourth non-inverse circuit that obtains an output (1, −1, 1) from the second input (−1, 0, 1), a fifth non-inverse circuit that obtains an output (1, 0, 1) from the second input (−1, 0, 1), a first complementary symmetry circuit that obtains an output complementarily symmetric with the output of the first non-inverse circuit, a second complementary symmetry circuit that obtains an output complementarily symmetric with the output of the second non-inverse circuit, a third complementary symmetry circuit that obtains an output complementarily symmetric with the output of the third non-inverse circuit, a fourth complementary symmetry circuit that obtains an output complementarily symmetric with the output of the fourth non-inverse circuit, and a fifth complementary symmetry circuit that obtains an output complementarily symmetric with the output of the fifth non-inverse circuit.
11. The three-valued logic function circuit according to claim 9 , wherein the third non-inverse circuit has an enhancement p-type MOS transistor connected to a source logic value 0 having a negative threshold voltage smaller in absolute value than a threshold voltage of a normal enhancement p-type transistor,
the fifth non-inverse circuit has an enhancement n-type MOS transistor connected to a source logic value 0 having a positive threshold voltage smaller than a threshold voltage of a normal enhancement n-type transistor,
the second complementary symmetry circuit has an enhancement n-type MOS transistor connected to a source logic value 0 having a positive threshold voltage smaller than a threshold voltage of a normal enhancement n-type transistor, and
the fifth complementary symmetry circuit has an enhancement p-type MOS transistor connected to a source logic value 0 having a negative threshold voltage smaller in absolute value than a threshold voltage of a normal enhancement p-type transistor.
12. The three-valued logic function circuit according to claim 10 , wherein the third non-inverse circuit has an enhancement p-type MOS transistor connected to a source logic value 0 having a negative threshold voltage smaller in absolute value than a threshold voltage of a normal enhancement p-type transistor,
the fifth non-inverse circuit has an enhancement n-type MOS transistor connected to a source logic value 0 having a positive threshold voltage smaller than a threshold voltage of a normal enhancement n-type transistor,
the second complementary symmetry circuit has an enhancement n-type MOS transistor connected to a source logic value 0 having a positive threshold voltage smaller than a threshold voltage of a normal enhancement n-type transistor, and
the fifth complementary symmetry circuit has an enhancement p-type MOS transistor connected to a source logic value 0 having a negative threshold voltage smaller in absolute value than a threshold voltage of a normal enhancement p-type transistor.