JPS63314846A - Single-layer wiring system - Google Patents

Abstract

PURPOSE:To substantially decrease a period of time required for designing lay-out, by searching for a path for a rectangular region consisting of a set of meshes so that a number of trials is thereby decreased substantially and a high wiring density is achieved. CONSTITUTION:A device for dividing rectangular regions 1 divides a wiring region into rectangular regions in which no terminal is included. A path searching device 2 searches for a path of a pair of terminals, for each of the rectangular regions. A device for determining presence of path 3 checks whether any path of other pairs of terminals is nullified by the searched path for, the pair of terminals. If it is determined that there is no possibility of presence of any path, a path changing device 4 changes the path searched by the path searching device. These operations of the devices 2, 3 and 4 are repeated so that a path of each pair of elements is determined for each rectangular, region, whereby a number of trials is decreased while achieving a high wiring density. Finally, a detailed path determining device 5 determines a path for each mesh within the subject region.

Description

[Detailed Description of the Invention] [Summary] Regarding the automatic design of wiring routes for printed circuit boards, large-scale integrated circuits, etc., the purpose of reducing processing time and improving the automatic wiring rate is to design the entire given wiring area internally. Rectangular area dividing means divides the area into rectangular areas that do not include any terminals, route searching means searches for a route for each divided rectangular area for one terminal pair, and routes for other terminal pairs are determined by the route searched by the route searching means. a route existence determining means for determining whether the route has become a terminal pair; a route changing means for modifying the route searched by the route searching means when it is determined that a route for another terminal pair no longer exists; and a dividing rectangle. A detailed route determining means is provided for determining a route in mesh units within the region for the route determined in each region, and the route search is performed in a rectangular manner by repeatedly performing processing by the route searching means, the route existence determining means, and the route changing means. After performing the determination for each area, the detailed route is determined for each mesh within the rectangular area.

[Industrial application field]

The present invention relates to printed circuit boards, large-scale integrated circuits (hereinafter referred to as LS),
(abbreviated as I) etc.).

When determining the wiring route on a printed circuit board or LSI, it is necessary to connect pairs of terminals that should have the same potential without crossing each other.When processing wiring in one layer, it is necessary to connect pairs of terminals that should be at the same potential by passing through another layer using a through hole. rather than
Routes must be determined so that there are no intersections within one layer.

This wiring route determination requires a large amount of processing time, and there is a desire to shorten the processing time.

[Conventional technology]

A method called the maze method is used as a typical conventional method for determining wiring routes in printed circuit boards and LSIs.

In the maze method, as shown in FIG. 6, for example, the board is divided into meshes, and each mesh is labeled from each point constituting a terminal pair to the other point.

In the example shown in FIG. 6, there are terminal pairs AA, BB, and CC in the board, and the board is divided into a 9x4 mesh. Labeling begins with one terminal A (X=3.Y=1
) to the upper and lower right of the cell.

Next, put "2" in the top, bottom, left, and right cells labeled rlJ.
Label. Similarly, another A (X = 6)
Labeling is also performed from Y=3).

A route is found when mutual labeling is performed on the same cell. In the figure, ■ indicates this. That is, ■ indicates that one A is labeled as "2" and the other A is labeled as "3".

A-1-■-■-1-A is the searched route.

Once a route is determined, cells on that route are prohibited from being used by other terminal pairs. In this way, the route for each terminal pair is determined one after another.

(Problem to be solved by the invention) In a method such as the maze method described above, in which routes are determined one after another for each terminal pair, the already determined patterns become obstacles for later wiring. It becomes difficult to avoid the occurrence of unroutable sections.

In particular, when the wiring is one layer, a method for effectively wiring a plurality of terminal pairs has not been established. Although this is theoretically possible by trying all possible route combinations, in practical problems it is often impossible because it requires a huge amount of processing time. The rate at which automatic wiring route determination by a computer is successful is called the automatic wiring rate.

In addition, the maze method has a high wiring ability that will always find a route if it exists for a single terminal pair, but it requires processing time in proportion to the area of the wiring area, so in large-scale circuits, the processing time is The problem is that it becomes very large.

The present invention aims to solve these conventional problems and provide a wiring system that further reduces processing time.

[Means for solving problems]

FIG. 1 shows a block diagram of the principle of the single layer wiring system of the present invention.

In the figure, reference numeral 1 denotes a rectangular area dividing means, which divides the wiring area of a given mesh structure into rectangular areas that do not include any terminals inside.

Reference numeral 2 denotes a route searching means, which searches for a route in units of divided rectangular areas for each terminal pair.

Reference numeral 3 denotes a route existence determining means, which determines based on the route searched by the route searching means 2 whether routes for other terminal pairs no longer exist.

Reference numeral 4 denotes a route changing means, which changes the route searched by the route searching means 2 when it is determined that a route for another terminal pair no longer exists.

Denoted at 5 is a detailed route determining means, which determines the route determined for each divided rectangular region by mesh within the region.

[For production]

In the present invention, first, the rectangular dividing means 1 divides a wiring area into rectangular areas that do not include any terminals inside.

For example, as shown in Figure 2, a 9x4 mesh wiring area is divided into rectangular areas ■, ■, ■, ■, ■, ■, ■ that do not include terminals A, A, B, B, C, and C. To divide. That is, the wiring area is divided into rectangular areas each consisting of a set of several meshes.

Next, the route search means 2 searches for a route for one terminal pair in each divided rectangular area. The search is performed using the conventional maze method.

Next, the route existence determining means 3 determines whether a route for another terminal pair exists based on the route searched for one terminal pair.
judge whether it has happened. Path existence judgment is performed by dividing one rectangular area into separate areas because it is a path for one terminal pair.
Even if paths of other terminal pairs share this rectangular area, they cannot cross this separation area, and the possibility of the existence of a path is determined based on the limitations imposed by the path passing capacity of each rectangular area.

When it is determined that there is no possibility of the route existing, the route changing unit changes the route searched by the route searching unit.

By repeating the processing by the route searching means 2, the route existence determining means 3, and the route changing means 4, the route for each terminal pair is determined in units of rectangular areas.

Regarding the route determined for each rectangular area, the detailed route determining means 5 determines a route for each mesh within the area.

In the present invention, a rectangular area is a set of meshes.

For example, by searching for a route at the same time, the number of search cells is reduced to 7 as shown in Figure 2, compared to 30 in the conventional example shown in Figure 5, and the search processing time is greatly reduced. By utilizing this and increasing the number of trials, a high wiring rate can be achieved as a result.

〔Example〕

The present invention will be explained in more detail below with reference to embodiments shown in FIGS. 3 to 5.

FIG. 3 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 4 is a diagram showing the processing progress according to an embodiment of the present invention.

Hereinafter, according to the block diagram of FIG. 3, the progress of the processing according to this embodiment will be explained with reference to FIG.

Te1) The preprocessing unit 10 divides the 'h'A SR area into rectangular areas that do not include terminals from the input initial data.

This is done by scanning each mesh in a rectangular manner within a range that does not include the terminal area. FIG. 4(a) is an example of initial data. The rectangular areas obtained by the rectangular area division are shown in FIG. 4(b). The upper left position and lower right position of each rectangular area are stored as a rectangular area table, and the positions of each terminal pair are stored as a terminal pair table.

(2) The route search unit 20 searches for a route for each terminal pair in units of rectangular areas. Route searching is performed using the maze method.

(3) The route existence possibility determining unit 30 determines whether the route of one terminal pair that has been searched for causes the route of another terminal pair to no longer exist. In the path existence possibility judgment, when two or more terminal pairs share one rectangular area, the intersection judgment section 31 judges whether or not an intersection occurs, and the capacity judgment section 32
This is done by determining whether or not exceeds the route passing capacity of the rectangular area. The intersection judgment according to the intersection judgment block diagram 31 is as follows.
As shown in FIG. 5, this can be done by comparing the coordinate values (W-i, s-j and W-m, S-n, etc.) of two routes in a rectangular area. In the example shown in FIG. 4, it is assumed that the route search unit searches for a route for wiring A in area ■. This route divides region (2) into two completely separate regions, as shown in FIG. 4(C). No other terminal pair path can cross this boundary. Therefore, in the wiring B, it is determined that the route used in the area (2)=O area (2)=6 area (2) shown in FIG. 4(d) has been lost due to the intersection determination. Therefore, the path of terminal pair B and C is as shown in Fig. 4 (e
), it is essential to use the area (2), but there is only room for one wire to pass through the area (2), and the capacitance determination unit 32 detects that the wiring is not possible.

(4) The route changing unit 40 is activated by the route existence possibility determining unit 3o's determination that wiring is impossible, and selects the area ■=O area ■=0 area ■ as the new route for A.

(FIG. 4(f)) The route change unit 40 stores routes that are determined to be unwirable, and selects other routes.

(5) As the wiring of the terminal pair C, the route search unit 2o
Assume that a route in area ■=6 area ■ is searched as shown in FIG.
It is determined that the path of terminal pair B is lost.

(6) The route change unit 40 changes the route of the terminal pair C to the area ■=0
Select the changed route in area ■. (Figure 4 (h)) (
7) The route search unit 20 determines the route for the terminal pair B by searching the area ■→area ■=O area ■→ as shown in FIG. 4(i).
Region ■=0 Region ■ is searched and the paths of all terminal pairs are determined at the region level.

(8) Finally, the detailed route determining unit 50 determines the
), a mesh-level route is determined within the area, and the wiring route determination process is completed.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to further increase the automatic wiring rate of wiring on printed circuit boards and LS''I, and there is an effect of significantly shortening the time required for designing the layouts thereof.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the principle of the present invention; Fig. 2 is a diagram showing rectangular area division according to the invention; Fig. 3 is a block diagram showing the configuration of an embodiment of the invention; Fig. 4 is an embodiment of the invention. FIG. 5 is a diagram showing an example of processing progress; FIG. 5 is a diagram showing an example of intersection determination; FIG. 6 is a diagram showing labeling using the maze method. In the drawings, l is a rectangular area dividing means, 2.20 is a route searching means (part), 3 is a route existence judgment means, 4 is a route changing means (part), 5.50 is a detailed route determining means (part), 30 31 represents a route existence possibility determining unit, 31 represents an intersection determining unit, and 32 represents a capacity determining unit, respectively. Principle block diagram of the present invention Figure 1 Input board data ■ Wiring route data Block diagram showing the configuration of an embodiment of the present invention Cl1l
~) fe)
fdl(el
+f1 Diagram showing the processing progress according to an embodiment of the present invention (Part 1) (g
) (h1
Figure 4-jS-n Figure 5 Diagram showing labeling by the labyrinth method (Part 2) Figure 6

Claims (1)

[Claims] In an automatic wiring process that divides a board into a mesh pattern and determines routes for wiring between a plurality of pairs of terminals on the board without crossing each other, the entire given wiring area is internally divided into terminals. rectangular area dividing means (1) that divides the area into rectangular areas containing no one; route searching means (2) that searches for a route in units of divided rectangular areas for one terminal pair; A route existence determination means (3) that determines whether or not there is no longer a route for another terminal pair based on the route; and a route search means (2) for searching when it is determined that there is no longer a route for another terminal pair. a detailed route determining means (4) for determining a route determined for each divided rectangular region on a mesh-by-mesh basis within the divided rectangular region;
5), the route search is performed in units of rectangular areas by repeatedly performing the processing by the route searching means (2), the route existence determining means (3), and the route changing means (4), and then the inside of the rectangular area is meshed. A single-layer wiring method characterized by being configured to determine detailed routes on a unit-by-unit basis.