JPH09232935A - Method for processing unused terminal in logic circuit element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent oscillation from being caused and to decrease the power consumption by connecting each output terminal and each input terminal of unit logic circuits not in use so as to form a closed circuit. SOLUTION: An input terminal 23 of a unit logic circuit INV connects to ground 4, and an output terminal 24 connects to a conductive section 12, an input terminal 25 of a circuit INV3 connects to ground 15, and an output terminal 26 connects to a conductive section 13, and then each input terminal of unit logic circuits not in use connects to ground. Furthermore, an input terminal 28 of a circuit INV4 connects to a short-circuit conductive section 11 and its output terminal 27 connects to a short-circuit conductive section 10, and an input terminal 30 of a circuit INV5 connects to a short-circuit conductive section 10 and its output terminal 29 connects to the short-circuit conductive section 11. Then as soon as a logic circuit element 1 is mounted on a printed circuit board, the input output terminals of the circuits INV4, 5 are in cross latch connection. Thus, a bistable circuit as a closed circuit is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of processing an unused unit logic circuit in a logic circuit element.

[0002]

2. Description of the Related Art Conventionally, when there is an unused unit logic circuit among a plurality of unit logic circuits mounted on a logic circuit element, an input terminal is always provided on a circuit board in order to prevent oscillation and avoid power consumption increase. It is connected to the high voltage side or the low voltage side. The high-voltage side or the low-voltage side means that the input terminal is relatively high-voltage side or low-voltage side.For example, when a negative voltage than the ground voltage is connected to the unit logic circuit, the ground side is the high-voltage side. Become.

[0003]

As shown in FIG. 2, the logic circuit element 1 includes, for example, INV1, INV2, INV3, INV4, INV in addition to the power supply terminal 2 and the ground terminal 3.
5, unit logic circuit of INV6 is mounted. When such a logic circuit element 1 is connected to an arrayed conductive portion during mounting on a printed circuit board as shown in FIG. 6,
Although it is necessary to connect the input terminal of each unit logic circuit to the power supply side or the ground side, there is the signal line 68 between the power supply unit 64 and the power supply separation unit 70, and the unit logic circuit INV4
Since there is no power source near the INV5 and INV5, it is necessary to newly provide a jumper wire 71 from the power source section 64 to the power source separating section 70. Therefore, the result is complicated and costly.

[0004]

The present invention has been made to solve the above problems, and as described in the claims, a plurality of unit logic circuits mounted on a logic circuit element have When connecting the input / output terminals of the used unit logic circuit to the circuit board and forming a closed circuit at the same time, or when connecting the input / output terminals of the unused unit logic circuit and other unused unit logic circuits, for example, By forming a closed circuit so that the closed circuit forms a two-state stable circuit, it is not necessary to install a jumper wire again.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION When connecting adjacent unused unit logic circuits to a circuit board, a closed circuit is formed by connecting the input terminal (s) of the unused unit logic circuit and the output terminal. By forming and forming a two-state stabilization circuit,
It is possible to prevent oscillation of the unused unit logic circuit and increase in power consumption. The output terminal of the unused unit logic circuit is connected to the input terminal of another unused unit logic circuit, and the input terminal of the unused unit logic circuit is connected to the output terminal of another unused unit logic circuit. Such wiring also forms a so-called two-state stabilizing circuit, which can prevent an increase in oscillation and power consumption.

[0006]

1 shows the connection of terminals when the logic circuit element 1 shown in FIG. 2 is mounted on a printed circuit board as shown in FIG.
There is not 1, but a power supply section 4, grounds 5, 14, 15, 16 and signal lines 6, 7, 8, 9, 1 as wiring made of an electric conductor.
7, 18, short-circuit conductive parts 10, 11 and conductive parts 12, 13
Are formed of printed conductors. Here, the power supply terminal 2 of the logic circuit element 1 is connected to the power supply unit 4. The ground terminal 3 is connected to the ground 16. Further, the input terminal 21 of the unit logic circuit INV1 is connected to the signal line 6 and the output terminal 2
2 is connected to the signal line 7, the input terminal 32 and the output terminal 31 of the unit logic circuit INV6 are connected to the signal line 9 and the signal line 8, respectively.

The input terminal 2 of the unit logic circuit INV2
3 is connected to the ground 14, the output terminal 24 is connected to the conductive portion 12, and the input terminal 25 of the unit logic circuit INV3 is connected to the ground 15
Further, the output terminals 26 are connected to the conductive portions 13, and the input terminals of the unused unit logic circuits are connected to the ground which is the low voltage side. Further, the input terminal 28 of the unit logic circuit INV4 is connected to the short-circuit conductive portion 11, the output terminal 27 is connected to the short-circuit conductive portion 10, the input terminal 30 of the unit logic circuit INV5 is connected to the short-circuit conductive portion 10, and the output terminal 29 is short-circuit conductive. Part 1
1 and the logic circuit element 1 is mounted on the printed circuit board, and at the same time the unit logic circuit INV4 and the unit logic circuit INV5 as shown in FIG. Therefore, a bistable circuit that is a closed circuit is formed.

FIG. 4A shows an embodiment in which the input / output terminals of the unit logic circuit 41 are connected by conductive lines 42 to form a closed circuit, and FIG. 4B shows the unit logic circuit. This is an embodiment in which a plurality of input terminals 47 and output terminals of the circuit 43 are connected by a conductive wire 44 to form a closed circuit. In both cases, circuit oscillation of the unit logic circuits 41 and 43 can be prevented. Further, FIG.
As shown in (B), the closed circuit of FIG.
There is no problem even if it is connected to 5.

[0009]

As described above, according to the present invention, when a logic circuit element having a plurality of unit logic circuits is mounted on a printed circuit board or the like, the terminals of unused unit logic circuits are mounted on the circuit board. At the same time, since the closed circuit is formed by connecting the output terminal and the input terminal of the closed circuit or the other unused unit logic circuit, it is not necessary to newly provide a jumper wire, and the cost can be reduced. .

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration in an embodiment of the present invention.

FIG. 2 is a schematic diagram of a logic circuit element equipped with a plurality of unit logic circuits.

FIG. 3 is a closed circuit diagram showing an embodiment of the present invention.

FIG. 4 is a closed circuit diagram of a unit logic circuit showing an embodiment of the present invention.

FIG. 5 is a schematic view showing wiring in another embodiment of the present invention.

FIG. 6 is a schematic diagram showing a configuration of a conventional technique.

[Explanation of symbols]

1: Logic circuit element 2: Power supply terminal 3: Ground terminal 4, 64: Power supply section 5, 14, 15, 16, 65, 74, 75, 76: Ground 6, 7, 8, 9, 17, 18, 66, 67, 68, 6
9, 77, 78: Signal line 10, 11: Short-circuit conductive part 12, 13, 72, 73, 79, 80: Conductive part 19, 81: Bypass capacitor 21, 23, 25, 28, 30, 32: Input terminal 22 , 24, 26, 27, 29, 31: output terminals INV1, INV2, INV3, INV4, INV5,
INV6, 41, 43, 55: Unit logic circuit 70: Power supply separation unit 71: Jumper wire

Claims (3)

[Claims] 1. A plurality of unit logic circuits mounted on a logic circuit element, wherein an input terminal and an output terminal of an unused unit logic circuit are mounted on a circuit board, and at the same time a closed circuit or another unused unit logic circuit is mounted. A method for processing an unused terminal in a logic circuit element, characterized in that a closed circuit is formed so as to be connected to an output terminal and an input terminal. 2. The method for processing an unused terminal in a logic circuit element according to claim 1, wherein the closed circuit is formed by one unit logic circuit. 3. A method of processing unused terminals in a logic circuit element according to claim 1, wherein the closed circuit comprises two unit logic circuits forming a two-state stabilizing circuit.