JPH04181416A - Radial bus - Google Patents

Abstract

PURPOSE:To transmit signals at high speed by making the lengths of transmission lines in a twisted state respectively equal and respectively connecting one end of each transmission line to a matching circuit. CONSTITUTION:A bus wiring board 5 radially arranges a front side signal line 6 composed of a conductor pattern and a rear side signal line 7 on the front and rear sides of an insulated panel with the central common connecting point of the insulated panel as a center so that the signal lines can cross through the insulated panel, these relative front side and rear side signal lines 6 and 7 are alternately connected while interposing a conducting hole 8, and the plural transmission lines having the equal length are radially formed. Further, one end of each transmission line is respectively connected to a matching circuit 9, and the other end of each matching circuit 9 is electrically connected to the external connection part of each processing element 13 arranged toward the outside along the periphery of each bus writing board 5. Thus, signals are transmitted at high speed and further, the transmission error of the signals is hardly generated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a bus that electrically connects components such as a CPU and a memory that constitute a computer.

(Prior Art) Conventionally, as an example of the hardware configuration of a computer, as shown in FIG. 8, each component such as a CPU and memory is mounted on a printed circuit board 1. The printed circuit boards 1 are connected to the connectors 2 with their mounting surfaces parallel to each other, and the connectors 2 are further electrically connected to each other to form a data bus, a control bus, and an address bus. It is known that the bus 3 is formed in a planar manner.

(Problem to be Solved by the Invention) In this way, conventionally, the bus 3 is formed in a planar manner, and a plurality of printed circuit boards 1 are arranged in parallel in the length direction of the bus 3, so that each of the CPU, memory, etc. When there are many components and the number of printed circuit boards 1 is large, the difference in distance between the printed circuit boards 1 increases and the distances also vary.

Therefore, with conventional buses, transmission times vary due to differences in transmission distance between each component such as the CPU and memory, making it necessary to control the time difference. This complicates transmission control and makes it difficult to transmit signals at high speed. The problem has arisen that it is difficult to process data at high speed.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a bus that can realize high-speed signal transmission without erroneous transmission, and can prevent both the influence of external noise and signal leakage.

(Means for Solving the Problems) In order to achieve the above object, the present invention was constructed as follows.

That is, in the present invention, front side signal lines and back side signal lines are arranged radially on the front and back sides of an insulating plate with a common connection point as the center so as to intersect with each other through an insulating plate, and both related signal lines are connected through conductive holes. Bus wiring boards in which a plurality of transmission lines of equal length are formed radially by intervening and alternately connected, and each end of each of the plurality of transmission lines is connected to one end of a matching circuit are stacked on the same axis. A plurality of matching circuits are arranged, and each other end of each of the matching circuits is electrically connected to an external connection portion of each processing element arranged outward along the periphery of each of the bus wiring boards. do.

(Function) In the present invention configured as described above, a unit of a set of related twisted transmission lines formed on bus wiring boards stacked on the same axis forms a parallel bus, and each of the related transmission lines is Assign each line to data lines, address lines, control lines, etc.

Furthermore, in the present invention, the lengths of the twisted transmission lines are equal, and each end of each transmission line is connected to a matching circuit, so that the distance between each processing element is electrically equal. In addition to equalizing the transmission distance between all processing elements, signal reflection is less likely to occur on the transmission line. Therefore, in the present invention, high-speed signal transmission can be realized.
Furthermore, signal transmission errors are less likely to occur.

Furthermore, in the present invention, since each transmission line is twisted, there is no electrostatic induction or magnetic induction, which increases resistance to external noise and eliminates unnecessary radiation from the transmission line. Therefore,
The present invention can prevent the influence of external noise and signal leakage,
This can contribute to the above-mentioned high-speed signal transmission and reduction of signal transmission errors.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

The bus wiring board 5, as shown in FIG. 1, is a double-sided printed circuit board on which conductor patterns are formed on the front and back sides of an insulating board in a form to be described later.

That is, the bus wiring board 5 connects the front side signal line 6 and the back side signal line 7, which are made of a conductive pattern, in a radial pattern on the front and back sides of the insulating plate, centering on a common connection point at the center of the insulating plate so as to intersect with each other through the insulating plate. The related front side signal lines 6 and back side signal lines 7 are connected alternately through conductive holes 8 to form a plurality of transmission lines of equal length radially (see FIG. 1).

One end of each of the front side signal line 6 and back side signal line 7 at the end forming each transmission line is connected to one end of each of the resistance R1 on the front side of the insulating plate and the resistance R1 on the back side of the insulating plate forming the matching circuit 9. (See Figures 2 and 3). As the resistor R1, a printed resistor, a chip resistor, etc. are suitable.

The other end of the resistor R1 on the front side of the insulating plate is connected to connection terminals 11 provided at equal intervals on the outer periphery of the front side of the bus wiring board 5 via the conductor 10.
Connect with. The other end of the resistor R1 on the back side of the insulating plate is connected to one end of a resistor R2 disposed on the front side of the insulating plate through the conduction hole 12, and the other end of the resistor R2 is connected to the connecting terminal 11.

Like the resistor R1, a printed resistor, a chip resistor, or the like is suitable as the resistor R2.

As shown in FIG. 4, the bus wiring boards 5 configured in this manner are arranged at equal intervals on the same axis in the vertical direction, and so that the signal lines 6.7 of each bus wiring board 5 are in the same phase. A predetermined number of pieces are placed in . Therefore, each unit of a set of related signal lines 6 and 7 arranged in the same phase forms a parallel bus. Each signal line 6.7 forming this parallel bus is assigned to a data line, an address line, a control line, etc., respectively.

Then, the printed circuit boards 14 on which the processing elements 13 are mounted are erected and arranged radially along the periphery of the bus wiring board 5 arranged in this way (see FIG. 5). Each printed circuit board 1
The external connection terminal 15 provided in 4 is a connector (not shown).
It is electrically connected to each corresponding connection terminal 11 of the bus wiring board 5 via the .

Incidentally, a socket 16 is attached to each connection terminal 11 of the bus wiring board 5, as shown in FIG. 2, to which each connection pin of the above connector can be attached and detached.

The processing elements 13 mounted on each printed circuit board]-4 include a processor (CPU), various types of memories, and an input/output processor that controls input/output devices such as a keyboard and a display device.

Next, an equivalent circuit for a high frequency signal of one transmission line constituted by signal lines 6 and 7 in the radial direction from the center of the bus wiring board 5 constructed as described above is shown in FIG.

In FIG. 6, C1 is the capacitance at both ends of the resistor R1, and C2 is the capacitance formed between the signal lines 6 and 7. And these capacitance C1 and capacitance C2
forms a matching circuit 9 as shown in the figure in combination with resistor R1 and resistor R2.

Next, a method of determining each value of the resistor R1 and the resistor R2 forming the matching circuit 9 will be explained.

Now, assuming that the number of radial transmission lines formed by the signal lines 6 and 7 on the bus wiring board 5 is N, this bus has (N-1) transmission lines in the equivalent circuit as shown in FIG. It is thought that transmission lines with similar equivalent circuits are branched and connected.

Therefore, when determining the values of resistance R1 and resistance R2,
In addition to considering the above points, the value of the characteristic impedance of the transmission line and the like may be taken into consideration to find an optimal value that allows impedance matching in the entire transmission system.

By forming each matching circuit 9 of each transmission line using the respective values of the resistor R1 and the resistor R2 determined in this way, unnecessary reflection of signals on the transmission line can be suppressed, and erroneous transmission between each processing element 13 can be suppressed. This makes it possible to transfer data at high speed.

In addition, since the signal line is in a twisted state formed by the front side signal line 6 and the back side signal line 7, there is no electrostatic induction or magnetic induction, making it resistant to external noise and suppressing unnecessary radiation from the transmission line. .

Furthermore, the bus of this embodiment includes a bus wiring board 5 in which a plurality of twisted transmission lines of equal length are formed radially from the center of an insulating board, and a matching circuit 9 is connected to each of the plurality of transmission lines. , were formed by arranging a plurality of them one on top of the other on the same axis. Therefore, if this bus is used to construct a computer system as shown in FIG. 5, even if a large number of processing elements 13 are connected, the overall length of the bus can be shortened and the computer system can be made more compact.

Next, another embodiment of the bus wiring board will be described with reference to FIG.

This bus wiring board 17 has two bus wiring boards 5 shown in FIG.
They are laminated together with a prepreg 18 interposed between them so that the signal line 6 of the lower bus wiring board 5 is located between each signal line 6 of the upper bus wiring board 5 in the L downward direction. This is what I did.

In the bus wiring board 17 constructed in this way, since the connection terminals 11 of the two bus wiring boards 5 are arranged in a staggered manner, a connector with connecting pins arranged in a staggered manner is used to connect the bus wiring board 17 as shown in FIG. A computer system can be created.

(Effects of the Invention) As described above, in the present invention, the twisted transmission lines have the same length, and each end of each transmission line is connected to a matching circuit, so that the distance between each processing element is Both are electrically equidistant, which equalizes the transmission distance between all processing elements, and makes it difficult for signal reflection to occur on the transmission line.

Therefore, according to the present invention, it is possible to realize high-speed signal transmission, and it is also possible to achieve the effect that signal transmission errors are less likely to occur.

In addition, in the present invention, each transmission line is twisted, so
Electrostatic induction and magnetic induction are eliminated, making it resistant to external noise and eliminating unnecessary radiation from the transmission line. Therefore, the present invention has the effect of being able to prevent the influence of external noise and signal leakage, which can contribute to the above-mentioned high-speed signal transmission and reduction of signal transmission errors.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an example of a bus wiring board, Fig. 2 is a sectional view showing its main parts, Fig. 3 is a perspective view showing the connection relationship between the conductor pattern and the resistor in Fig. 2, and Fig. 4 is a plan view showing an example of the bus wiring board. Figure 5 is a perspective view of a computer system configured using a bus wiring board; Figure 6 is a diagram showing an example of the arrangement of a bus wiring board; Figure 6 is a diagram showing one transmission line configured radially from the center of the bus wiring board; An equivalent circuit for a high frequency signal, FIG. 7 is an exploded perspective view showing another embodiment of the bus wiring board, and FIG. 8 is a diagram illustrating a conventional technique. 5.17 is a bus wiring board, 6.7 is a signal line, 9 is a matching circuit, and 13 is a processing element. Patent applicant Gerafico Co., Ltd. Agent Tobe Maki (3 others) Figure 1 Figure 2 Figure 4 Figure 5

Claims (2)

[Claims] (1) The front side signal line and the back side signal line are arranged radially on the front and back of the insulating plate with a common connection point as the center so as to intersect with each other through the insulating plate, and both of these related signal lines are connected through a conduction hole. A plurality of bus wiring boards are stacked on the same axis, in which a plurality of transmission lines of equal length are connected alternately to form a radial pattern, and each end of each of the plurality of transmission lines is connected to one end of a matching circuit. and each other end of each of the matching circuits is electrically connected to an external connection portion of each processing element arranged outward along the periphery of each of the bus wiring boards. bus. (2) The radial bus according to claim 1, wherein the matching circuit is formed by a plurality of resistors and a capacitance formed between the transmission lines.