JPH06163696A - Grouping method for same potential terminal - Google Patents

Abstract

PURPOSE:To extract a terminal point in a cell from a physical pattern data in the cell, conduct grouping which provides a significant meaning to the extract terminal point and thereby generate a library. CONSTITUTION:When grouping an aluminum layer or a polylayer wiring, terminal points A1 to A7 and aluminum layer wirings L1a to L1d and L2 are formed into one group while terminal pints B1, B2 and aluminum layer wirings L3a to L3c are formed into the other group. When grouping the aluminum layer wirings, the terminal points A1, A2 and the aluminum layer wirings L1a to L1d are formed in one group while terminal point A4 and A5 and the aluminum layer wiring L2 are formed into the other group. Terminal points A3, A6 and A7 are not formed into a group by independent respectively. The terminal points B1 and B2 and the aluminum layer wirings L3a to L3c are formed into the other group. Furthermore, there exists the aluminum layer wiring at a different potential only on the terminal pointy A3. Therefore they are set different from the other terminal points and aluminum layer wirings.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of grouping equipotential terminals in a cell in consideration of the physical pattern and electrical characteristics of the cell in the development of a semiconductor integrated circuit.

When connecting cells formed of transistors by wiring in the design of a semiconductor integrated circuit, if the wiring length becomes long, the wiring capacitance may be deteriorated and the characteristics may be lowered, or the wiring rate may be lowered or unconnected. . Therefore, in the wiring process, it is necessary to connect each cell to a terminal that has a short wiring length and that has an electrical characteristic that reduces the deformation of the signal waveform.

It is also necessary to be able to handle the same potential point in the cell as a terminal in order to be able to wire to a terminal inside the cell using an automatic wiring program.

Therefore, it has become important how to store the cell information in a file and form a library.

[0005]

2. Description of the Related Art Conventionally, in a cell library in which information of each cell of a functional unit forming a semiconductor integrated circuit is stored in a file, the terminal information of each cell is limited to a single point set on the frame of the cell. Was defined as a terminal.

Therefore, the cell library is generated by overlooking the point that can be handled as a terminal inside the cell or on the aluminum-containing layer wiring.

[0007]

Therefore, when the conventional cell library is used to perform the wiring process by the automatic wiring program, there arises a problem that the redundancy of the wiring length is caused or the wiring cannot be performed in consideration of the electrical characteristics. Was there.

The present invention has been made in order to solve the above problems, and extracts terminal points in a cell from physical pattern data in the cell and performs grouping in which the extracted terminal points have meaning. The purpose is to do and generate a library.

[0009]

In order to achieve the above object, according to the first aspect of the invention, physical pattern information of each cell of a functional unit forming a semiconductor integrated circuit is inputted and all the same potential terminals are connected. All points on the wiring were grouped as terminals with the same potential, and made into a library.

In the second aspect of the invention, among the grouped equipotential terminals, the terminals connected only by the aluminum-containing layer wiring are set as another group to form a library.
In the third invention, among the equipotential terminals grouped,
Of the terminals that should be the same potential terminals that exist on the same poly layer wiring mainly composed of polysilicon, exclude the terminals that have aluminum containing layer wiring of different potential from the group of the same potential terminals and make a library. I chose

[0011]

Therefore, in the first aspect of the present invention, it is possible to define all the points in the cell that have the same electric potential, so that the degree of freedom in wiring processing is improved.

Further, in the second invention, by grouping only the aluminum-containing layer wiring, if the groups are different even at the same potential, the terminal will be across the poly layer wiring, so that it has an electrical characteristic. The signal waveform will be different. Such grouping is information necessary for performing wiring processing in consideration of electrical characteristics.

Further, in the third invention, it is possible to recognize whether or not the terminal can be connected by the presence information of the aluminum-containing layer wiring of different potential, so that the processing efficiency is improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a grouping device for carrying out the present invention. The cell library file 5 is connected to the input side of the grouping device 1, and the cell library file 6 is connected to the output side.

The cell library file 5 stores physical pattern data of each cell in functional units designed by an LSI design support device such as a CAD device. FIG. 4 is a layout diagram of an example of cells stored in the cell library file 5. This cell is composed of transistors. A terminal point A is provided on the poly layer wiring LP1 as a gate.
2 and A3 are set. A terminal point B2 is set on the poly layer wiring LP2 as a gate, and a terminal point B1 is set on the poly layer wiring LP3 as a gate. Further, the terminal point A is provided on the poly layer wiring LP4 as a gate.
1, A4 to A7 are set.

The terminal point A1 and the terminal point A2 are connected by aluminum-containing layer wirings L1a to L1d. The terminal point A4 and the terminal point A5 are connected by the aluminum-containing layer wiring L2. Further, the terminal point B1 and the terminal point B2 are connected by aluminum-containing layer wirings L3a to L3c. Further, the aluminum-containing layer wiring L4 having a different potential exists in the upper layer above the terminal point A3. In addition, each aluminum-containing layer wiring of this embodiment has 99% aluminum (A
1) and a metal composed of 1% silicon (Si). Hereinafter, in the present embodiment, the aluminum-containing layer wiring is simply referred to as an aluminum layer wiring.

The grouping device 1 is composed of a first group setting section 2, a second group setting section 3 and a different potential terminal setting section 4. The grouping device 1 inputs the physical pattern data of each cell from the cell library file 5,
Each terminal point and aluminum layer wiring included in the pattern data are grouped.

Then, the grouping device 1 stores the grouped terminal information in the terminal information table of the cell library file 6 to make the information of each cell into a library.

That is, the first group setting section 2 groups all the terminal points on all the poly layer wirings and the points on the aluminum layer wirings that are connected as the same potential terminal.
For example, as shown in FIG. 3, terminal names A11 to A16, A
Set the group number α of 21 to “1” and set the terminal name A2
2, the group number α of A23 is set to “2”.

Of the equipotential terminals grouped by the first group setting section 2, the second group setting section 3 sets, as a second group, terminals connected only by aluminum layer wiring excluding poly layer wiring. . For example, as shown in FIG. 3, the group number β of the terminal names A11 to A13 and A21 is set to “1”, and the group number β of the terminal names A14, A22 and A23 is set to “2”. Also, terminal names A15, A
The group number β of 16 is set to “3”.

Further, the different potential terminal setting unit 4 sets, as the different potential terminal, the terminal having the aluminum layer wiring of different potential among the terminals which should be the same potential terminal existing on the same poly layer wiring, that is, They are not grouped as equipotential terminals. For example, as shown in FIG. 3, the terminal name A16
The group number γ of is set to “present”, and the group numbers γ of the other terminal names are set to “absent”.

FIG. 2 shows the processing executed by the grouping device 1. First, in step 11, it is determined whether or not all the logic terminals (terminal points) of the cell library file 5 have been registered. If there is an unregistered logic terminal, at step 12, one unregistered terminal point is input and the point is stored in the terminal information table.

In step 13, it is judged whether or not the aluminum layer wiring of different potential exists at the target point. If it exists, the terminal information table number γ is "present", and if not, the terminal is present. The information table number γ is set to “none”.

At the next step 14, the group number α for the aluminum layer wiring or the poly layer wiring and the group number β for only the aluminum layer wiring at the current point are set in the terminal information table.

After that, the process proceeds to step 15, and when it is determined that the aluminum layer wiring not registered in the terminal information table is connected to the current point, the next connection point of the connected aluminum layer wiring is determined in step 16. For the parts up to, group numbers α and β are set in the terminal information table.

Then, in step 17, the process moves to the next connection point, the process returns to step 13 and the processes of step 13 and thereafter are executed. If it is determined in step 15 that the aluminum layer wiring not registered in the terminal information table is not connected to the current point, the process proceeds to step 18.

When it is determined in step 18 that there is another point in which the group is not registered on the pattern of the poly layer wiring in which the current point is present, the process moves to the above point in step 19.

Thereafter, in step 20, the above step 1
The group number β of the point moved in 9 is converted into a value not registered as another group number. Then, the processing from step 13 onward is executed.

If it is determined in step 18 that there is no other point for which the group is not registered on the pattern of the poly layer wiring in which the current point is present, step 21
Proceed to.

When it is determined in step 21 that the current point is a position moved by another aluminum layer wiring of the same potential from the pattern of another poly layer wiring, the process proceeds to step 22. In step 22, the points are returned to the original position, and the group number β is returned to the original value. Then, the process returns to the step 15, and the processes after the step 15 are executed.

If it is determined in step 21 that the current point is not a location moved from another poly layer wiring pattern by the equipotential aluminum layer wiring, the process proceeds to step 23. In step 23, the group number α is converted into a value that is not registered as another group number. Then, the process returns to step 11, and the processes after step 11 are executed. Step 11
When it is determined that all the logic terminals (terminal points) of the cell library file 5 have been registered, the processing ends.

Therefore, when terminal grouping is executed for the cell pattern data shown in FIG. 4, first, the terminal points A1 to A7 and the lines L1 to L5 are output as terminal information.

The terminal points A2 and A3 are connected by a poly layer wiring LP1. Terminal points A1 and A4 to A7 are poly layer wirings L
It is connected at P4. The terminal points A1 and A2 are connected by aluminum layer wirings L1a to L1d. The terminal point A4 and the terminal point A5 are connected by the aluminum layer wiring L2. Further, the terminal point B1 and the terminal point B2 are connected by aluminum layer wirings L3a to L3c. Further, the aluminum layer wiring L4 is connected to the terminal point A3.

Therefore, since the terminal points A1 to A7 and the aluminum layer wirings L1a to L1d and L2 are connected by the aluminum layer wiring or the poly layer wiring, the group number α is, for example, "1" as shown in FIG. It is set and all are considered to be in the same group. Terminal points B1, B2, aluminum layer wiring L3
Since a to L3c are connected by aluminum layer wiring, as shown in FIG. 5, the group number α is, for example, “2”.
Are set to, and all are considered to be in the same group.

The terminal points A1 and A2 and the aluminum layer wiring L
Since 1a to L1d are connected only by the aluminum layer wiring, the group number β is set to, for example, "1" as shown in FIG. Since the terminal point A3 is not connected to other terminal points by the aluminum layer wiring, the group number β is set to “2”, for example, as shown in FIG. Terminal point A
4, A5 and the aluminum layer wiring L2 are connected only by the aluminum layer wiring, so that the group number β is set to, for example, "3" as shown in FIG. Terminal points A6, A7
Is not connected to other terminal points with aluminum layer wiring,
As shown in FIG. 5, the group number β is, for example, “4”,
Each is set to "5". Since the terminal points B1 and B2 and the aluminum layer wirings L3a to L3c are connected by the aluminum layer wiring, the group number β is set to, for example, "6" as shown in FIG.

Further, since the aluminum layer wiring having the different potential exists only on the terminal point A3, only the number γ of the terminal point A3 is set to "present". “None” is set to the other terminal points and the aluminum layer wiring number γ.

As described above, in this embodiment, it is possible to obtain a library in which the terminal points of the cells and the aluminum layer wirings connecting the terminal points are grouped so as to have a meaning. Therefore, if the wiring process of each cell is performed by the program of the automatic layout using the information of this library, the layout efficiency can be improved by increasing the terminal information of the cell.

That is, by grouping with aluminum layer wiring or poly layer wiring, it is possible to define all points having the same electric potential in the cell, so that the degree of freedom in wiring processing can be improved. it can.

Also, if the groups are different even at the same potential due to the grouping using only the aluminum layer wiring, the terminal will be across the poly layer wiring, so the electrical characteristic signal waveform will be different. Become. By this grouping, it is possible to perform wiring processing in consideration of electrical characteristics.

Further, since it is possible to recognize whether or not the terminal can be connected by the presence information of the aluminum layer wiring of different potential, it is possible to improve the processing efficiency. In this embodiment, 99% aluminum and 1% are used as the aluminum-containing layer wiring.
Although a metal composed of silicon is used, a metal containing aluminum as a main component and a trace amount of another metal may be used as the aluminum-containing layer wiring. For example, as the aluminum-containing layer wiring, a metal mainly containing aluminum and containing 1% of copper may be used. Further, the aluminum-containing layer wiring may be formed only of aluminum.

[0041]

As described in detail above, according to the present invention,
It is possible to obtain a library in which cell terminals are grouped with meaning. Therefore, if the automatic layout program uses the information of this library to perform the wiring process of each cell, there is an effect that the layout efficiency can be improved by increasing the terminal information of the cell.

[Brief description of drawings]

FIG. 1 is a schematic view of a grouping device according to an embodiment.

FIG. 2 is a flow chart showing the operation of one embodiment.

FIG. 3 is an explanatory diagram showing a terminal information table according to an embodiment.

FIG. 4 is a layout diagram of a cell including transistors.

FIG. 5 is an explanatory diagram showing an example of a terminal information table.

[Explanation of symbols]

 A1 to A7 terminal points L1 to L5 lines

Claims (3)

[Claims] 1. A physical pattern information of each cell of a functional unit forming a semiconductor integrated circuit is input, and all points on wirings connected as equipotential terminals are grouped as equipotential terminals to form a library. A method for grouping equipotential terminals characterized in that. 2. The equipotentials according to claim 1, wherein among the grouped equipotential terminals, terminals connected only by aluminum-containing layer wiring are set as another group to form a library. Terminal grouping method. 3. Among the grouped equipotential terminals, aluminum-containing layer wirings having different potentials are present among terminals to be the equipotential terminals existing on the same poly layer wiring mainly composed of polysilicon. The method for grouping equipotential terminals according to claim 1, wherein the terminals are excluded from the group of equipotential terminals to form a library.