JP2761119B2 - Programmable wiring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable wiring in which, for example, in a semiconductor integrated circuit, a connection between wiring elements of a wiring channel in which a plurality of wiring conductors (referred to as wiring elements) are arranged in parallel is programmable.

[0002]

2. Description of the Related Art Some semiconductor devices allow connection between wiring elements of a wiring channel to be programmed so that a user can configure a desired logic circuit.

Some of such semiconductor devices are provided with a switching matrix for determining a connection relationship between wiring elements at intersections of wiring channels in order to make programmable connections between the wiring elements. FIG. 5 shows an example of the configuration.

As shown in FIG. 5, this semiconductor device has a functional module 1 including a programmable logic circuit and the like.
It has a plurality of zeros. The area between the functional modules 10 is a region of the wiring channel 11 (referred to as a channel region), and the wiring element 12 is provided in each of the wiring channels 11 in the vertical direction and the horizontal direction. The switching matrix 14 is provided at the intersection of the wiring element 12 in the vertical and horizontal directions.
Is installed.

The switching matrix 14 turns on and off a programmable switch that can turn on and off arbitrary wiring elements 12 in each direction (indicated by reference characters N, S, E, and W in FIG. 5) according to a program input from the outside. It has a function of completing the wiring by connecting by turning off. Ideally, if programmable switches are provided at the intersections of all wirings of the switching matrix 14, the degree of freedom of connection between wiring elements is maximized.

[0006]

However, since the programmable switches of the switching matrix are usually made of a static random access memory (SRAM) having a large area, the switches are provided at the intersections of all the wirings. And there is a limit to the number of installations. Therefore, it is necessary to arrange the programmable switches in the switching matrix within the above limits.If the arrangement position is determined arbitrarily, when connecting the switches according to a program,
There is a problem that an unusable wiring element is generated.

The present invention has been made in order to solve the above-mentioned conventional problems, and provides a programmable wiring in which a programmable switch in a switching matrix can be provided so that connection can be made without generating an unusable wiring element. The task is to

[0008]

SUMMARY OF THE INVENTION According to the present invention, there is provided a semiconductor device, comprising: a plurality of wiring elements provided side by side in a semiconductor device, and a plurality of wiring elements arranged side by side; A switching matrix including a programmable switch for selectively on / off connection in accordance with the following, and in a programmable wiring in which the connection between wiring elements in the switching matrix is programmable, By providing a smaller number of programmable switches than the number, and making the number of programmable switches for connecting each wiring element in the direction of going straight less than the number of programmable switches for connecting each wiring element in the bending direction This has solved the above problems.

[0009]

In the programmable wiring, if the programmable switches of the switching matrix can be installed at all the intersections between the wiring elements, free connection can be made without limitation, which is ideal. Is large, the number of programmable switches that can be installed is limited.

In this case, the programmable switch includes:
From the viewpoint of the function, the connection in the straight traveling direction (for example, the connection from the W-direction wiring element 12 to the E-direction wiring element 12 shown in FIG. (Connection to the element 12). If these types of programmable switches are arranged without any restrictions, there is a possibility that wiring elements that cannot be used when connecting wiring elements according to a program may occur.

Therefore, the inventor has conducted various investigations on what proportion of the two types of programmable switches are used in various types of semiconductor integrated circuits. FIG. 2 shows the result of the investigation.

FIG. 2 shows a standardized wiring length, where d is a standardized wiring length, and which wiring pattern connects the wiring elements in the bending direction and the wiring pattern connected in the straight direction for wiring between lengths d to 5d. In this study, it was investigated whether or not it was used on a semiconductor integrated circuit. That is, each wiring length d to 5
d, the turning direction (indicated by symbol L), the straight traveling direction (indicated by symbol-
), The number of cases where each wiring pattern is used,
The occupation ratio (share) of each wiring length d to 5d with respect to the entire wiring length and the ratio of each wiring pattern having each wiring length d to 5d with respect to the entire wiring length are shown.

FIGS. 3A to 3E show patterns of respective wirings at respective standardized wiring lengths d to 5d.

FIGS. 4A to 4E show an example in which the wiring is extended to the standardized wiring lengths d to 5d from the center up, down, left, and right.

In the result of FIG. 2, the ratio of the total number of wiring patterns connected in the straight direction to the total number of wiring patterns connected in the bending direction is 29.2: 70.8, which is about 0.41: 1. ing.

Considering this result, in the switching matrix, the number of programmable switches for connecting the wiring elements in the straight direction is smaller than the number of the programmable switches for connecting in the bending direction,
As in the example of FIG. 1 actually applied, preferably, if the ratio between the two is provided between 0.35: 1 to 0.5: 1, connection can be made in accordance with various wirings. is there.

According to the present invention, when each wiring element is connected by a programmable switch, it is possible to reliably prevent generation of an unusable wiring element. Therefore, since the switching matrix can be configured only with necessary programmable switches, the area of the switching matrix can be reduced without impairing the function of the programmable wiring.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings.

In this embodiment, in the semiconductor device shown in FIG. 5 described above, three wiring elements 1, 3 in each of directions N, S, E, W provided in the switching matrix 14 are provided.
The present invention is applied to a programmable switch for connecting a few switches.

In this embodiment, a programmable switch is provided in the switching matrix 14 as schematically shown in FIG.

In FIG. 1, in the switching matrix, each programmable switch for connecting each wiring element 12 in a straight traveling direction and a bending direction is indicated by “○” and “●”, respectively. As shown in FIG. 1, there are provided 12 programmable switches in the straight traveling direction, and 28 programmable switches in the bending direction. Therefore, the ratio of the number of programmable switches in the straight traveling direction and the bending direction is 12: 28 = 0.43:
Becomes 1.

Furthermore, in the wiring element group in the same direction (for example, 1, 2, and 3 of E), some of the programmable switches connected to the wiring elements 1 and 3 around the wiring channel 11 are omitted, and the central wiring is omitted. A programmable switch is always provided between the elements 2-2.

As a result, even when a complicated and crowded wiring state is used due to the large number of wiring elements to be used, the occurrence of unusable wiring elements rarely occurs.

In the above embodiment, the switching matrix of the programmable switch as shown in FIG. 1 has been exemplified. However, the programmable switch for implementing the present invention is not limited to the configuration shown in the figure.
The point is that the arrangement ratio between the programmable switches for connecting in the straight traveling direction and the turning direction is 0.35: 1 to 0.
If the ratio is between 5: 1, the switches can be provided in an appropriate arrangement.

[0025]

As described above, according to the present invention, it is possible to surely prevent generation of unusable wiring elements when connecting programmable wirings according to programming. Therefore, an excellent effect that the area of the switching matrix can be reduced without lowering the effect of the programmable wiring can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an arrangement of programmable switches in a switching matrix according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a distribution of programmable switches in a straight line direction and a bending direction with respect to a wiring length, for explaining the principle of the present invention;

FIGS. 3A to 3E are schematic diagrams showing examples of various wiring patterns.

FIGS. 4A to 4E are schematic diagrams showing other examples of various wiring patterns.

FIG. 5 is a plan view showing an example of a programmable wiring in a channel region wiring of the semiconductor integrated circuit.

[Explanation of symbols]

10: Functional module, 12: Wiring element, 14: Switching matrix.

Claims (3)

(57) [Claims] (1)A plurality of devices provided vertically and horizontally in a semiconductor device
A wiring channel in which wiring elements are juxtaposed, and the wiring channel
At the intersection of the wiring elements according to the program
Programmable switch for selective on / off connection
A switching matrix including a switch, Connection between wiring elements in the switching matrix
Programmable connection Programmable wiringsmell
hand,Said Connect to switching matrixPossibleAll unions
Fewer programmable switches than
Programmer to connect each wiring element in the direction going straight
Cable switches in the direction in which each wiring element is bent.
Smaller than the number of programmable switches for
And a programmable wiring. 2. The method of claim 1, against the direction of the straight
The number of programmable switches for connection, the ratio between the number of programmable switches for connecting to the bending direction, 0. 35 : a programmable wiring characterized by being between 1: 1 and 0.5: 1. 3. The wiring according to claim 1, wherein the wiring is in the same direction.
Within the element group, the routing elements near the periphery of the routing channel
Omit some of programmable switches to connect,
Programmable wiring, characterized in that a programmable switch is always provided between wiring elements near the center of the wiring channel .