JPS6366675A - Compaction system for layout - Google Patents

Abstract

PURPOSE:To perform the partial compression in a layout compaction system by releasing the coupling relation between a fixed pattern and an internal pattern to replace it with the virtual connecting relation and compressing this relation by means of a longest route method. CONSTITUTION:A segments means 1 for area to be compressed segments a designated compressed area out of the graphic data to be processed. A fixed/ internal pattern separating means 2 separates a fixed pattern included partly in the compressed area and a fixed pattern overlapping said pattern from other internal patterns. A coupling relation release means 3 turns the coupling relation between fixed and mobile patterns into the virtual connecting relation. A compression processing means 4 produces a limit flag that decides the limiting conditions for compression from those data produced by means 1-3 and searches the longest route to shift patterns. Then a coupling process means 5 reconnects the relations among patterns which are once released by the means 3 based on the shift results of patterns.

Description

[Detailed Description of the Invention] [Summary] This is a method for partially compressing a part of an integrated circuit or a printed circuit board, an f-out pattern, and a fixed figure fixed to a compressed area frame. This method separates the internal figures to be compressed and moved, cancels the bond between the fixed figure and the internal figure, replaces it with a virtual bond, and compresses using the longest path method. Partial compression is now possible even when

[Industrial Field of Application] The present invention relates to the layout of integrated circuits and printed wiring boards, and particularly to a partial compaction method for layout patterns.

Manual design is no longer able to keep up with the rapidly increasing scale and density of integrated circuits, and high-density manual design is becoming necessary to avoid violating complicated design rules (specifying the minimum spacing between figures). Layout is extremely inefficient.

To solve this problem, humans input the relative positional relationship from a global perspective by providing sufficient spacing between the elements.
Compaction is an attempt to automatically remove the free space contained therein by a computer.

[Prior Art] Conventionally, one of the following methods has been used to compress layout patterns.

(1) No function corresponding to partial compression is used.

(2) Move the designated graphical element as much as possible in the designated direction and transform the wiring pattern accordingly.

(3) Fill the rectangular frame (window) that does not intersect with graphical elements other than wiring in the specified direction.

[Problems to be Solved by the Invention] With the conventional compaction method described above, (1) cannot respond in detail to the designer's request to modify only one class area.

In (2), it may take a lot of effort to specify each graphic element and movement direction.

In (3), windows can only be specified using a relatively sparse pattern.

There was a problem.

The present invention aims to provide a novel compaction method that solves these conventional problems.

[Means for Solving the Problems] FIG. 1 shows a block diagram of the principle of the layout compaction method of the present invention.

In FIG. 1(a), numeral 1 denotes a compressed area cutting means, which cuts out a specified compressed area from graphic data to be processed.

Reference numeral 2 denotes a fixed/internal figure cutting means, which cuts figures outside the compression area and part of the pressure wJ area, as well as figures overlapping with each other, as fixed figures, and cuts the rest as internal figures.

Reference numeral 3 denotes a connection relationship release means, which guides the connection relationship between the fixed figure and the moving figure into a virtual connection relationship.

FIG. 1 fb) shows the content structure of the connection relationship cancellation means 3.

Reference numeral 31 denotes a boundary line segment selection means, which selects a vertical line segment coming out of a compressed area frame or a fixed figure as a boundary line segment when the compression is in the horizontal direction.

Reference numeral 32 denotes a virtual line segment selection means, which selects a virtual line segment by tracing the connection relationship of the internal line segment relationship from the boundary line segment.

33 is a barrier figure selection means which selects a figure which becomes a barrier when the virtual line segment moves. When the compression is to the left, select the fixed figure on the left side of the virtual line that restricts the movement of the virtual line to the left, select the internal figure on the right side of the virtual line, and Obtain external barrier staircase data that acts as a barrier when moving to the left.

Reference numeral 34 denotes a virtual line segment movable range calculating means, which calculates the movable range of each virtual line segment based on the barrier figure selected by the barrier figure selecting means 33.

4 is a compression processing means, which creates a constraint graph that defines compression conditions from the data created by each of the means 1 to 3, searches for the longest path, and executes figure movement.

Reference numeral 5 denotes a combination processing means, which recombines the connection relationships of the graphic relationships that have been once canceled by the connection relationship cancellation unit 3, based on the result of the graphic movement.

[Operation] The partial compaction method according to the present invention improves layout and
This compresses only within an arbitrarily specified rectangular area of the pattern, and does not move figures that intersect with the area boundary or figures that overlap directly or indirectly, but instead creates a wiring pattern that connects the moved figure and the fixed part. By appropriately changing , it is possible to compress a part of a complex and crowded layout pattern.

Therefore, the wiring connection relationship between the fixed figure and the movable figure is temporarily canceled and replaced with a virtual connection relationship, and subsequent reconnection is guaranteed by compression, and the movement width is limited to avoid violating design rules. , After compression, reconnection processing between the fixed figure and the moving figure is performed.

[Example] The present invention will now be described in more detail with reference to Examples shown in FIGS. 2 to 7.

FIG. 2 is a block diagram showing the configuration of a system that performs compression processing of a layout pattern of an integrated circuit, which is an embodiment of the present invention.

In FIG. 2, 601 is a compaction control unit that controls the entire compaction process.

A graphic data/design rule storage unit 701 stores data such as graphic data and design rules.

A preprocessing unit 101 reads design rules, graphic data, compression area designation data, etc., and cuts out the pressure area w3.

The design rule stores the minimum spacing between each layer (polysilicon, metal, contact, etc.) of the integrated circuit, and further stores the maximum value related to each layer and the maximum value among them as the maximum rule value for all layers. .

A fixed figure/internal figure dividing unit 201 separates internal figures to which compression is applied and fixed figures to which compression is not applied.

Reference numeral 301 is a boundary line/virtual line segment selection unit, which divides the vertical line segment that spans the frame fixed part and the interior at the boundary when the compression is in the horizontal direction, creates multiple vertical line segments, and selects the internal line segment. is selected as a boundary line segment, and a line starting from the frame fixed part of the boundary line segment to an internal figure or branch of the line segment is selected as a virtual line segment.

Reference numeral 302 is a virtual line segment movable range calculation unit that searches for barriers and calculates the movable range of the virtual line segment.

A constraint graph creation unit 401 creates a constraint graph with each figure as a node and the minimum interval rule of each figure relationship as an edge.

A longest route search unit 402 searches for a route with the maximum sum of technique lengths among the routes from the start point to the end point in the constraint graph.

403 is a wiring length minimization unit, which is a longest route search unit 40
The direction in which each node is packed is selected so as to minimize the sum of the wiring lengths of horizontal line segments when the figure is moved as determined by the longest path determined by 2.

A figure moving unit 404 moves the figure based on the constraints of the longest path and the movable range of each virtual line segment.

503 is a polygonal line pattern determination unit that generates a polygonal line pattern along the barrier.

FIG. 3 is a diagram showing a method of storing graphic data in this embodiment.

As shown in the figure, there is a table for each type of shape (rectangle, polygon, line segment), a table for each shape type (rectangle, polygon, line segment), and a table where multiple shapes come together like a transistor and have a single function, and the relative relationship between those shapes can be changed. Data for items that cannot be used is provided as an element table.

Figures included in the same element are connected by element links. In addition, the overlapping relationship between figures is provided as an overlapping table, which is connected by overlapping links.

FIG. 4 is a diagram showing divisions of graphic data in this embodiment.

In cutting out the region to be compressed in the preprocessing unit 11, the specified compression region is cut out as a window frame as shown by a thick line, and the outside by the maximum rule value of all layers is cut out as an enlarged frame as shown by a broken line.

The fixed figure/internal figure cutting section 21 cuts out fixed figures and internal figures as shown in FIG. 4 as follows. .

That is, objects outside the enlarged frame are not stored in the figure table as being out of scope, and figures that are even partially included in the enlarged frame are stored in the figure table.

Among the figures to be handled, figures that partially protrude from the window frame (-next frame fixed) and figures in an overlapping relationship therewith (secondary frame fixed) are selected as fixed figures, and other figures are selected as internal figures. However, all figures belonging to an element are treated as one figure group.

FIG. 5 is a diagram showing barrier figures for virtual line segments.

The virtual line segment movable range calculation unit 32 calculates the movable distance for each virtual line segment as follows when the direction of compression is to the left.

(1) Select the internal figure on the right side of the virtual line segment as the right internal barrier figure.

(2) The fixed figure on the left side of the virtual line acts as a barrier to the leftward movement of the virtual line and limits the range of movement, so it is selected as the left fixed barrier figure.

(3) Virtual line division When moving to the left, it becomes a polygonal line along the external barrier pattern and gradually rises as the external barrier pattern changes, restricting the leftward movement of the internal figure selected in Tl). Create this as left external barrier staircase data.

(4) Find the movable range of the virtual line segment from the data obtained in (t) to (3), and calculate the smallest one as the movable range of the virtual line segment.

FIG. 6 is a diagram illustrating a constraint graph according to the present invention.

The constraint graph creation unit 41 creates a node table and a branch table for the compression target pattern as shown in FIG. Connect each node and connect the rightmost 7
(sink).

Duplicate figure groups, elements, polygons, and vertical line segments are registered in the node table, and horizontal line divisions are ignored.

To create a branch table, first find the left-hand side vector of each figure, find the extended right-hand side vector by extending the right-hand side by the design rule, and set techniques based on the constraint relationship with the left-hand side vector to the right of each extended right-hand side vector. The minimum distance between the reference points (minimum point of the X coordinate) of both figures determined from the design rules is defined as the length of the technique.

Figure 6 (bl) shows the constraint graph of the compression target pattern in Figure 6 (a), where the length of the technique and the cost are entered for the multi-branches.The cost is calculated when there is a connection between the two shapes. , where the cost is the number of horizontal line segments, and the wiring length minimization unit 40
This is used for the wiring length minimization process in step 3.

Based on the constraint graph shown in FIG. 6('b), the longest route search unit 42 determines which route from the source 1 through each node to the end point 7 has the longest sum of the lengths of the multiple branches. Find a route. In the example of the constraint graph in Figure 6(b), ■−■−
■−■ is the longest path, and this longest path length is the limit of leftward compression, and no further compression is possible.

FIG. 7 is a diagram showing line dispersion reduction in a polygonal line pattern.

After the internal figure is moved in accordance with the compression limit and the movable range of each virtual line segment in the figure moving unit 44, the line pattern determining unit 51 determines the line pattern of the virtual line segment.

Virtual line division A polygonal line is generated along the external barrier stairs as shown in the figure (al), and the number of line segments of the polygonal line pattern is reduced as shown in the figure (mountain) to determine the polygonal line pattern.

The compressed pattern thus obtained is stored in the graphic data/design rule storage section 7, and the horizontal compaction process is completed.

After this, vertical compaction processing is performed as required.

[Effects of the Invention] As explained above, according to the present invention, in a pattern including arbitrarily distributed fixed figures, the fixed figure/internal figure relationship is changed to a virtual one, and the virtual connection is performed. Since the compression-coupling relationship is created from the relationship, partial compaction can be successfully performed even in highly congested patterns, and the effect on automation of the design of large-scale integrated circuits is extremely large.

[Brief Description of the Drawings] Fig. 1 is a block diagram of the principle of the system, Fig. 2 is a block diagram showing the configuration of an embodiment of the present invention, and Fig. 3 is a method of storing graphic data in an embodiment of the present invention. 4 is a diagram illustrating a method for dividing graphic data according to the present invention; 50th is a diagram illustrating a barrier figure for a virtual line segment according to the present invention; FIG. 6 is a diagram illustrating a constraint graph according to the present invention; FIG. 7 is a diagram showing line dispersion reduction of a polygonal line pattern according to the present invention. In the drawings, 1 is a compressed area cutting means, 2 is a fixed/internal figure cutting means, 3 is a coupling relationship release means, 4 is a compression processing means, 5 is a coupling processing means, 31 is a boundary line segment selection (stage, 32 3 is a virtual line segment selection means, 33 is a barrier figure selection means, 34 is a virtual line segment movable range calculation section, 101 is a preprocessing section, 201 is a fixed figure/internal figure separation section, 301 is a boundary line segment/virtual line 302 is a virtual line segment movable range calculation unit, 401 is a constraint graph creation unit, 402 is a longest route search unit, 403 is a wire length minimization unit, 404 is a figure movement unit, 501 is a polygonal line pattern determination unit, 601 indicates the compaction control section, and 701 indicates the graphic data/design rule storage section.
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Claims (2)

[Claims] (1) In the compression process of layout patterns of integrated circuits, printed wiring boards, etc., a compressed area extraction means (1) that cuts out the compressed area to be compressed, fixed figures that are not compressed or moved, and fixed figures that are not compressed or moved. A fixed/internal figure separation means (2) that separates the target internal figure.
), a bonding relationship canceling means (3) that temporarily cancels the bonding relationship between the fixed figure and the internal figure and replacing it with a virtual bonding relationship, and performing a compression process according to the processing result of the bonding relationship canceling device (3). a compression processing means (4); and a combination processing means (for performing recombination processing between the fixed figure and the internal figure after the compression by the compression processing means (4) is completed);
5), a layout compaction method characterized in that it is configured to compress an arbitrarily specified portion of a layout pattern. (2) The connection relationship release means (3) includes a boundary line segment selection means (31) that selects a line segment that spans the frame fixed part and the interior and is perpendicular to the compression direction as a boundary line segment, and a frame for the boundary line segment. Virtual line segment selection means (
32), barrier figure selection means (33) which selects internal barrier figures and fixed barrier figures that act as barriers to the movement of the virtual line segment and creates external barrier staircase data, and virtual line segment movable range calculation means (33).
4) The layout compaction method according to claim 1, characterized by comprising: