JPH10294373A - Automatic wiring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the layout of a wiring pattern in a short time which ensures the wiring of its characteristics and occupies small area, by a method wherein an automatic wiring is carried out by neglecting a through-hole design rule, and then modifications are automatically made later so as to eliminate the violation. SOLUTION: An automatic wiring operation is carried out, using a wiring grating where a square through-hole whose side is equal to the short side of a through-hole different in an aspect ratio is employed (101). Then, through-holes which violate a design rule are searched, and an aggregate of through-holes which violate the design rule is obtained. Thereafter, violation elimination processing (103 to 107) formed of a combination of first processing where through-holes which violate a design rule are moved, second processing where the through-holes are rotated by an angle of 90 deg., and third processing where a wiring is made to bypass the through-holes are executed by making processing where a wiring is less changed in length prior to other processing, whereby violation of a through-hole design is eliminated. By this setup, a layout of wiring pattern small in area can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an automatic wiring method in a layout design of a semiconductor integrated circuit.

[0002]

2. Description of the Related Art Conventionally, an automatic wiring method for a semiconductor integrated circuit has been designed so that a design rule is not violated based on a size of a through hole, a width of a wiring line, and a minimum space between wiring patterns. The wiring and the through-hole are placed on the wiring grid that defines the above. When the aspect ratios of the through holes are different, wiring is performed using wiring grids having different vertical and horizontal intervals according to the size of the through holes. When such a grid is used, an invalid area between wirings becomes large. As a method for removing an invalid area and obtaining a layout pattern having a small area, compression by layout compaction has been reported (Japanese Patent Application No. 5-674).
Also, after using a wiring grid in the case of using a square through hole with the short side of the through hole as one side, and allowing the violation of the design rule of the through hole, performing automatic wiring,
A method of manually resolving the violation by using an interactive wiring route correction tool or the like has also been used.

[0003]

FIGS. 2 and 3 show examples of enlargement of the wiring grid spacing when through holes having different aspect ratios are used. FIG. 2 shows an example of a wiring model in which through holes are prohibited from being placed on adjacent grid points on the upper, lower, left and right sides.
In such a model, when a square through hole is used (FIG. 2A), the distance between the corner of the through hole (201) and the corner of the oblique horizontal through hole (202) is the minimum of the wiring pattern. The vertical and horizontal grid intervals (204, 205) are determined so as to be the intervals (203). In the case where the through holes in FIG. 2A are made horizontally long (FIG. 2B), since the through holes are spread horizontally, a vertical constraint is generated between the through holes. (21
In 3), the distance is determined so that the distance between the upper and lower through holes (206, 207) becomes the minimum distance (211) between the wiring patterns. In addition, since the height of the through-holes does not change, there is no restriction between the through-holes in the horizontal direction. Therefore, the horizontal lattice spacing (212) is the minimum distance between the through-holes and the wirings. Determine the interval so that Since the wiring grid spacing determined in this manner is larger in both the vertical and horizontal directions than in FIG. 2A, the layout size when a horizontally long through hole is used (FIG. 2-B) even if the wiring path is the same. Is larger.

FIG. 3 shows an example of a wiring model that allows through holes to be placed on adjacent grid points in the vertical, horizontal, and horizontal directions. In such a model, regardless of the shape of the through-holes, the distance between adjacent through-holes,
Minimum spacing between wiring patterns (301, 302, 305,
306). The vertical lattice spacing obtained in this manner is the same in the case of a square through-hole (304) and in the case of a horizontally long through-hole (308). In the case of the horizontally long through-hole, the case of the horizontally long through-hole (308) is wider than that of the case (303) by the increased width of the through-hole. The layout size in FIG. 3B is larger.

[0005] As described above, in the method of performing wiring so as not to violate the design rule by using the wiring grids having different vertical and horizontal intervals in accordance with the design rule, the interval between the wirings is widened and the wiring density is reduced. I do. In order to increase the wiring density, compaction may be performed after wiring, but in the case of wiring considering characteristics such as delay time, the wiring length changes at the time of compression, so it is necessary to increase the compression ratio while maintaining the characteristics. Have difficulty.

In the automatic wiring method in which a violation is permitted, the violation is eliminated manually, so that the wiring is corrected only in the vicinity of the violating through hole, and changes in characteristics such as delay time are reduced. However, it is not appropriate to use this method for an integrated circuit having a large number of through holes.

[0007] In order to solve these problems, the present invention allows automatic wiring by permitting violation of the design rule of the through-hole, and then automatically corrects the violation to eliminate the violation, so that through-holes having different aspect ratios can be obtained. An object of the present invention is to provide a method for obtaining a layout pattern having a small area in a short time while maintaining the characteristics of wiring even in a large-scale integrated circuit used.

[0008]

Means for Solving the Problems In order to avoid the layout size becoming large because the through holes are horizontally long, first, when a square through hole having one short side of the through hole as a side is used. Automatic wiring is performed by using a wiring grid that does not violate the design rules and allows the violation of the design rule of the through-hole, and the wiring and the position of the through-hole are determined. Next, a place where an actual rectangular through hole violates a design rule is searched.
Next, using the empty area of the wiring and the invalid area between the wirings, moving the through-hole in a range that does not cause disconnection to the violating through-hole and the wiring and the through-hole of the violating partner. Violation resolution processing that combines processing, 90-degree rotation of through-holes, through-hole moving with partial wiring layer change, through-hole moving with lead-out, and wiring detour around the through-hole Is executed with priority given to a process with a small change in wiring length, thereby eliminating through-hole design rule violations.

By the above processing, the characteristics of the wiring are maintained,
A layout pattern with a small area can be obtained.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a PAD diagram showing an outline of a processing procedure of a wiring processing. First, automatic wiring is performed using a wiring grid in the case of using a square through hole in which the length of the shorter side of a through hole having a different aspect ratio is one side (101). In a wiring model in which it is prohibited to place through holes at adjacent grid points on the left, right, upper and lower sides of the through hole, as shown in FIG. 4A, the size of the through hole and the distance between the oblique horizontal through hole (401) Is determined so that is the minimum distance between the wiring patterns. If the wiring using this wiring grid is a square through hole, it does not violate the design rules.
However, the shape of the through hole is changed to the actual size (FIG. 4-b).
In this case, the design rule is violated (402-404) between the through hole and the vertical wiring segment and the design rule is violated (405) between the through holes. Allow the violation and perform automatic wiring.

Next, a search is made for through-holes that have violated the design rule, and a set of violating through-holes is obtained (1).
02).

Next, for a through-hole that causes a design rule violation, the elimination of the violation (103) by a combination of the through-hole moving process within a range that does not cause disconnection and the through-hole 90-degree rotation process will be described. Do. The range that does not cause disconnection is a range in which the height and width of the through-hole and the wiring segment connected to the through-hole are equal to or larger than the width of the wiring segment in the overlapping area of the through-hole and the wiring segment, In the case of the through-hole and the terminal, the height and width of the rectangle of the overlapping region of the through-hole and the terminal are within a range not shorter than before the movement. This processing (103) will be described with reference to FIGS. 4 and 5.

First, the moving process of the through-hole within the range where the disconnection does not occur is executed separately in the vertical direction and the horizontal direction. In the vertical movement, the violation of the design rule due to the vertical restriction is eliminated by moving the through holes in the vertical direction.

In the example of FIG.
Violation (405) due to a vertical constraint has occurred between 07 and 07. To resolve this violation (405), move through hole 407 upward or
Move down through hole 406 or 407 and 406
Must be moved up and down by １ ／ of the required movement amount. When the 407 is moved upward, a violation due to a new vertical constraint occurs between the 407 after the movement and the upper wiring, so that the 407 cannot be moved. Then 40
In the case of moving down 6, the amount of movement is within a range that does not cause disconnection, and the movement is possible because all vertical constraints on 406 are eliminated. 40
When moving 6 and 407 up and down respectively, 4
If 07 does not cause a violation with the upper wiring, it can be moved.

FIG. 4C shows a state in which the restriction in the vertical direction has been successfully removed by moving 406 downward. For all through-holes having design rule violations due to vertical constraints, the violations due to vertical movement are eliminated, and violations due to the vertical constraints that can be resolved are resolved.

Next, for a violation that cannot be eliminated by moving in the vertical direction, the violation is eliminated by moving in the horizontal direction.
When moving horizontally, regardless of the constraints that cause the violation,
Move only when all of these violations can be resolved.
After the end of the vertical movement processing, in the example of FIG.
Lateral violation of wiring segments and through holes (40
2,403,404) remain. To eliminate these violations, the through holes 407 and 408 are moved to the right and the through hole 406 is moved to the left. These movements are in a range in which the amount of movement does not cause disconnection, and the through hole after movement is in a state where all violations have been eliminated in both the vertical direction and the horizontal direction, and thus can be moved. By the above movement, FIG.
As shown in (1), a wiring result without design rule violation is obtained.

Next, if the violating through-hole remains after the above-described moving process is completed, the violating through-hole is rotated by 90 degrees (vertically long if horizontal), and then again. The violation is eliminated by executing the moving process of the through hole within the range where the disconnection does not occur. About this process,
This will be described with reference to FIG.

In the example shown in FIG.
01, 502, and 503) cause violations (505 to 510) with the wiring segments, so that the design rule violation cannot be eliminated only by vertical and horizontal movement. In such a case, among all the violating through holes, all of the through holes that can be rotated 90 degrees without disconnection are rotated. As a result, as shown in FIG. 5B, all violations between the through hole and the left and right vertical wirings are eliminated, but the through hole 501 and the upper horizontal wiring are rotated because they are vertically elongated. A violation (511) due to a vertical constraint occurs between them, and a violation (504) due to a vertical constraint between the through hole 501 and the through hole 502.
Remains as a violation (512) due to the restriction in the horizontal direction.

In order to resolve these violations, the violations caused by the above-mentioned vertical movement are eliminated, and the through holes 5 are removed.
01 by moving it down, the violation with the upper wiring (5
11) is resolved, and only the violation due to the restriction in the lateral direction between the through holes 501 and 502 remains as shown in FIG. Next, by moving the through hole violated by the lateral movement to the left and right, the violation due to the lateral restriction between the through holes is eliminated, and a wiring result free from the design rule violation shown in FIG. After the above processing is completed, the through-holes for which all of the violations have not been eliminated even if rotated 90 degrees are rotated again to return to the horizontally long state.

In the above processing, the length of the wiring and the wiring layer are not changed, so that the characteristics of the wiring are maintained.
However, if all the violations cannot be eliminated by these processes, the movement of the through-hole with the partial wiring layer change,
Movement of a through-hole accompanying withdrawal of wiring and elimination of design rule violation due to detour of wiring are executed. Among these processes, first, the violation is eliminated (104) by the combination of the movement of the through-hole accompanied by the partial change of the wiring layer and the movement of the through-hole within the range where the disconnection does not occur. This processing will be described with reference to FIG.

As shown in FIG. 6A, the through holes (601 to 605) are formed by bending a plurality of parallel wirings in a bundle.
Are caused by violations (606 to 610) due to restrictions in the horizontal direction with the wiring on the right side and violations (611 to 614) due to restrictions in the vertical direction with the through holes obliquely above and below. Movement of the through-hole within a range that does not occur cannot eliminate the vertical violation between the through-holes. In such a case, the violation due to the restriction in the vertical direction between the through holes is ignored, and the violation due to the restriction in the horizontal direction with the wiring on the right side is set every other (601, 603, 605). Move to the left by the distance necessary to resolve (FIG. 6-b). By this processing, the violation due to the horizontal restriction of the wiring and the through hole (606, 60
8,610) is eliminated. Next, the through holes (602, 604) that did not move are replaced with the lower right through hole (6, 6).
01, 603) while moving a part of the horizontal wiring segment to the vertical wiring layer to the position where the horizontal distance between the wiring patterns becomes the minimum distance between the wiring patterns (FIG. 6).
c). As a result of this movement, all violations due to horizontal restrictions are eliminated, and only violations (612, 614) due to vertical restrictions on obliquely upward or downward through holes remain. When violation elimination is performed on these through-holes (602 to 604) by moving in the vertical direction, FIG.
As shown in FIG.

Next, the violation is eliminated (105) by a combination of the movement of the through-hole accompanied by the drawing out of the wiring and the movement of the through-hole within a range where the disconnection does not occur.
This process will be described with reference to FIG. As shown in FIG. 7A, the through holes (701 to 705) where a plurality of parallel wirings are bent as a bundle are violated (706 to 710) due to the horizontal restriction with the wiring on the left side, and obliquely upward. Violations (711-714) due to the vertical restriction with the through hole obliquely below occur, and as in the example of FIG. Violations due to directional constraints cannot be resolved. In such a case, ignoring the violation due to the restriction in the vertical direction between the through holes, every other through hole arranged diagonally (701, 703, 705) restricts the horizontal direction (706, 706) with the left wiring. 708, 710) to the right by the distance necessary to resolve the violation (FIG. 7).
-B). Next, the through holes that did not move (702, 7
04) to the right while pulling out the upper wiring segment and the lower wiring segment until the horizontal space between the lower left through hole (701, 703) becomes the minimum space between the wiring patterns (FIG. 7-c). By this movement, all violations due to horizontal restrictions are resolved,
Alternatively, only the violation (712, 714) due to the restriction in the vertical direction for the through hole obliquely below remains. When the violation elimination is performed on these through holes by moving in the vertical direction, a wiring result without violation shown in FIG. 7D is obtained.

Next, detour processing is performed on the wiring adjacent to the through-hole, processing for moving the through-hole within a range where disconnection does not occur,
Elimination of violation by combination of 90-degree rotation processing (10
Execute 6). This processing will be described with reference to FIGS.

First, the violation caused by bypassing the vertical wiring adjacent to the through hole is eliminated. Fig. 8-a
Since the through-hole (801) is surrounded by wiring segments on the upper, lower, left and right sides of the through-hole, the violation caused by the movement of the through-hole cannot be eliminated. In such a case, the vertical wiring (8) causing the violation (804, 805) with the through hole along the periphery of the rectangle (806) in which the through hole is expanded outward by the minimum distance of the wiring pattern.
02, 803) to eliminate the violation (Fig. 8-
b).

As shown in the example of FIG. 9B, when the detoured wiring (906) causes a violation of the design rule (908) with other wiring segments, terminals, and through holes, the wiring is not detoured.

Next, the violation is eliminated by combining the movement of the through hole and the detour of the wiring. In the example of FIG. 9, the through hole is moved in the horizontal direction in a direction that eliminates the restriction (905) with the wiring (902) on the side where the detour of the wiring has failed (FIG. 9-c). The violation is eliminated by bypassing the wiring (903) in which the violation (904) due to the hole and the lateral constraint is generated, and the violation shown in FIG. 9D is eliminated.

Next, the through-hole, whose violation has not been eliminated by the above processing, is rotated by 90 degrees. If the opponent of the violation of the through hole after rotation is horizontal wiring,
Similar to the detour of the vertical wiring, the violation is eliminated by detouring the horizontal wiring. After this process is completed, the through holes for which the violation has not been resolved are rotated 90 degrees again to return to the previous state.

Finally, for the remaining violating through-holes, a process combining the process of further detouring the detour wiring and the wiring causing the violation and the process of rotating the through-hole by 90 degrees.
The violation by (107) is eliminated. In this process,
In order to detour several wires around the through hole in order,
This is executed last because the change in the wiring length is larger than in the processing up to now. This process will be described with reference to FIG.

In the example of FIG. 10A, the through hole (10
01) has a violation (1004, 1005) with the left and right vertical wirings (1002, 1003). In order to eliminate this violation, the wiring (1002, 1003) is bypassed (FIG. 10-b). Wiring 100 bypassing wiring 1002
No. 6 causes a violation (1008) with the left wiring 1007. The wiring 1009 that bypasses the wiring 1003 includes a wiring 1010 on the right side and a through hole (1
012) and violations (1013, 1014).

These violations (1008, 1013, 10
14), bypass wiring (1006, 100
A process to bypass 9) is performed. First, a rectangle (1016) enlarged by the width of the minimum interval is obtained for the detour wiring (1006) causing the violation, and the wiring 1007 is detoured along this rectangle. Next, a rectangle (1
017), the wiring 1014 is bypassed along this rectangle, and the through hole 1012 is moved. By moving through hole 1012, horizontal wiring 10
In the case where the overlap with the wire 19 becomes insufficient and the wire breaks, the wire 1019 is extended in the moving direction of the through hole 1012 to secure the overlap.

FIG. 10C shows the result of the process of bypassing the bypass wiring (1006, 1009). There is no constraint violation in the newly bypassed wiring (1015, 1018), but the moved through hole 1012 causes a violation (1020) with the right wiring 1014. In order to eliminate this violation, a process for bypassing the through hole 1012 is performed. As with the previous detour processing, the through hole 1012
Is obtained by enlarging by a width corresponding to the minimum interval (1021), and the wiring 1014 is detoured along this rectangle (FIG. 10-d). Detour wiring (1
022) does not cause a design rule violation.

Through the above processing, all design rule violations relating to the violating through-hole, the wiring bypassing the through-hole, and the through-hole are eliminated. Until there is no violation of the detour portion, the process of detouring the detour wiring is repeated to eliminate the violation. In the middle of the repetition, if a violation occurs other than the wiring and the through hole such as the terminal and the wiring prohibited area, the processing is interrupted, and the part bypassed so far is returned. Next, the remaining through-holes in which the violation has not been eliminated are rotated by 90 degrees, and the process of bypassing the wiring in the horizontal direction up and down is repeated in the same manner as in the above-described detour processing to eliminate the violation.

[0033]

According to the present invention, even in a large-scale integrated circuit using through-holes having different aspect ratios, a short side of the through-hole is made one by performing automatic wiring while permitting violation of the through-hole. It is possible to obtain a layout pattern having the same area as the case where a square through hole is used. In addition, by automating the process of resolving through-hole violations and by giving priority to processing that does not change wiring characteristics in the process, layout characteristics that maintain wiring characteristics and are free from design rule violations are maintained. Can be obtained in a short time.

[Brief description of the drawings]

FIG. 1 is a processing procedure diagram of automatic wiring according to the present invention.

FIG. 2 is an explanatory diagram of how to determine a wiring grid interval.

FIG. 3 is an explanatory diagram of how to determine a wiring grid interval.

FIG. 4 is an explanatory diagram of the elimination of a violation due to movement of a through hole according to one embodiment of the present invention.

FIG. 5 is an explanatory diagram of 90-degree rotation of a through-hole and elimination of a violation due to movement of the through-hole according to one embodiment of the present invention.

FIG. 6 is an explanatory diagram of the elimination of a violation due to movement of a through-hole accompanied by a partial layer change of a wiring according to one embodiment of the present invention.

FIG. 7 is an explanatory diagram of violation elimination due to movement of a through-hole accompanying withdrawal of wiring according to one embodiment of the present invention.

FIG. 8 is an explanatory diagram of violation elimination by detour wiring according to one embodiment of the present invention.

FIG. 9 is an explanatory diagram of a violation elimination by detour wiring and movement of a through hole according to one embodiment of the present invention.

FIG. 10 is an explanatory diagram of violation elimination by a process of further bypassing the bypass wiring according to the embodiment of the present invention.

[Explanation of symbols]

101 to 107: processing steps of automatic wiring processing, 20
1,202 ... square through holes, 206-208 ...
Horizontal through holes, 203, 210, 210, 30
1, 302, 305, 306: minimum spacing between wiring patterns, 204, 212, 303, 307: horizontal grid spacing, 205, 213, 304, 308: vertical grid spacing, 401: minimum between wiring patterns Interval, 402-40
4: Violation of design rule due to lateral restriction, 405 ...
Violation of design rules due to vertical constraints, 406-40
8 ... through-hole, 501-503 ... through-hole, 5
04, 511: Violation of design rules due to vertical constraints, 505 to 510, 512: Violation of design rules due to horizontal constraints, 601 to 605: Through holes, 60
6 to 610: Violation of design rules due to horizontal constraints,
611 to 614: Design rule violation due to vertical restriction, 701 to 705: Through hole, 706 to 710: Design rule violation due to horizontal restriction, 711 to 714: Design rule violation due to vertical restriction, 801: Through hole , 802, 803 ... wiring to be detoured, 80
4,805: Violation of design rules due to horizontal constraints,
806: rectangle in which the through hole is enlarged by the width of the minimum interval of the wiring pattern; 807, 808: bypass wiring;
907: through-hole; 902, 903: wiring to be bypassed; 904, 905, 908: violation of design rules due to lateral restrictions; 906: bypass wiring;
1012: Through-hole, 1002, 1003, 100
7, 1010, 1014 ... wiring to be detoured, 10
04,1005,1008,1011,1013,10
20: Violation of design rules due to lateral restrictions, 100
6, 1009, 1015, 1022 ... bypass wiring, 101
6, 1017: a rectangle in which the detour wiring is enlarged by the minimum interval width of the wiring pattern; 1021: a rectangle in which the through hole is enlarged by the minimum interval width of the wiring pattern.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shoichi Hanaki 5-2-1, Josuihoncho, Kodaira-shi, Tokyo Inside Hitachi RLS Engineering Co., Ltd. (72) Inventor Toshihiro Hattori Tokyo 5-20-1, Josuihonmachi, Kodaira-shi Semiconductor Company Semiconductor Division

Claims (2)

[Claims] In an automatic wiring method of a semiconductor integrated circuit using through holes having different aspect ratios, a process of moving through holes in a layout in which wiring is performed while permitting the through holes to violate design rules. And a process of rotating the through hole by 90 degrees, a process of bypassing the wiring around the through hole, and a combination of these processes to eliminate the violation of the design rule. 2. The automatic wiring method according to claim 1, wherein a change in characteristics such as a delay time is reduced by giving priority to a process with a small change in wiring length.