JPS63121979A - Wiring route searching device - Google Patents

Abstract

PURPOSE:To reduce the frequency of occurrence of cross talk by setting a line length limiter included in a specific lattice point string on a wiring lattice in matching with the specific length of a substrate, prior to searching a wiring route, and searching the route while said line length limiter is recognized. CONSTITUTION:With respect to section data transmitted from a wiring control part 1, a wiring route searching part 8 evades a wiring inhibition position and an existing wiring route by referring to a wiring lattice map 3. Simultaneously the part 8 recognizes the line length limiter 1 and searches the wiring route while limiting below a length specified from the outside with the length of a line segment including a lattice point where the line length limiter 11 lies as a parameter 2. When finding a desired wiring route, the wiring route searching part 8 sends it to the wiring control part 1; otherwise, the fact is reported to the wiring control 1. Only when the wiring route is sent from the wiring route searching part 8, the wiring control part 1 sets it to the wiring lattice map 3 as a fault in the subsequent wiring route search, and simultaneously outputs it to wiring route data 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wiring route searching device used for wiring design of printed wiring board integrated circuits and the like.

[Conventional technology]

BACKGROUND ART Conventionally, it has been thought that a wiring route generated by a wiring route search device used for wiring design of printed wiring boards, integrated circuits, etc. should be shortest and have fewer curved points and fewer vias.

Therefore, the length of the line segments constituting the wiring route is not limited as long as they do not significantly interfere with other wiring.

Documents related to such prior art include the incorporated association
A publication published by the Information Processing Society of Japan [CA of Logic Devices]
You can refer to DJ.

[Problem that the invention seeks to solve]

The above-mentioned conventional wiring route searching device may generate a long line segment adjacent to another wiring route as part of the wiring route, so it is not suitable for today's high-density printed wiring boards with narrow wiring grid spacing. However, there was a drawback in that crosstalk occurred between adjacent lines, leading to malfunction of the logic circuit.

[Failure to solve the problem]

The wiring route search device of the present invention is a means for storing the occupancy state of each grid point of a wiring grid and whether or not a line length limiter exists on a grid point for limiting the length of a line segment constituting a wiring route. and means for generating the line length limiters at specific intervals on a specific grid point array on a wiring grid, and a wiring including a grid point on which the line length limiter is present during a wiring route search It has means for limiting the length of the route groove bottom line segment to a specific length or less.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

Referring to FIG. 1, the wiring control unit 1 in one embodiment of the present invention first sets parameters related to the line length limiter 11 (FIGS. 2 and 3) that limits the length of line segments constituting the wiring route. 2, the wiring grid map 3 that stores the occupancy status of each grid point of the wiring grid and whether or not the line length limiter 11 exists on the grid point is cleared. Next, wiring control section 1
inputs the wiring prohibition data 4 and the existing wiring route data 5, and sets them in the wiring grid map 3 as obstacles during wiring route searching. Further, the wiring control section 1 sends information regarding the generation position of the wire length limiter 11 given from the outside as a parameter 2 to the wire length limiter generation section 6. A mark indicating the presence of the line length limiter 11 is set at the corresponding position above. The method of generating the line length limiter 11 will be explained in detail later using FIG. 3.

Next, the wiring control unit 1 sequentially selects 1 from the wiring section data 7.
Data for the section is extracted and sent to the wiring route search section 8.

The wiring route search unit 8 refers to the wiring grid map 3 for the section data transferred from the wiring control unit 1 to avoid wiring prohibited positions and existing wiring routes, and recognizes the line length limiter 11. Then, a wiring route is searched while limiting the length of the line segment including the lattice point where the line length limiter 11 exists to a length specified from the outside as parameter 2 or less.

Note that the method of limiting the length of a line segment by the line length limiter 11 will be explained in detail later using FIG. 2.

When the wiring route searching section 8 finds a desired wiring route, it transfers the wiring path to the wiring control section 1, and when it cannot find it, it notifies the wiring control section 1 to that effect.

In the wiring control unit 1, only when a wiring route is transferred from the wiring route searching unit 8, the wiring route is set in the wiring grid map 3 as an obstacle in the subsequent wiring route search, and is output to the wiring route data 9. do. The above operation is repeated for all the wiring target sections, and the process is completed.

Next, using Fig. 2, select the line segment by the line length limiter 11 - one of the line segments, and the line segment 12 is one of the line segments constituting the wiring route currently being searched, and the arrow indicates the line segment to be searched. It shows the direction. While searching from the lattice point to the right on the line segment 12, when the line length limiter 11 is detected, immediately calculate the distance (n) from the lattice point to the line length limiter 11, and use the parameter 2 (
By subtracting from the limit length (m) given in Figure 1), we can find the width (P) of the section in which the search can continue without changing direction.
Calculate. Then, by controlling the search for the wiring route so as to change the search direction or move to another layer via a relay hole (pier hole), the line segment that contacts the line length limiter 11 is The length can be kept within the limit length (m).

The method of generating the line length limiter 11 will be explained with reference to FIG. 3(at) and FIG. 3(b) show an example of generation of the line length limiter 110 for the X layer and the y layer, respectively. In the X layer, as shown in FIG. By generating the line length limiters 11 at intervals on the grid point sequence, the lengths of all the X-direction line segments running on this grid point sequence are limited to within m.

In addition, by selecting every other horizontal grid point array that generates the line length limiter 11, the length of adjacent portions of parallel adjacent line segments on the X layer is always limited to within m. will be done. The same applies to the Y layer as well as the X layer. Line length limiter 11
It is not necessarily necessary to occur regularly on the wiring grid, and it is also possible to set it only in a specific area depending on the characteristics of the board.

By applying the device of the present invention to automatic wiring on printed wiring boards, etc., long adjacent parallel wiring can be effectively reduced without significantly impeding wiring performance.

〔Effect of the invention〕

As explained above, the present invention sets line length limiters at intervals of one leg at specific grid points on a wiring grid in accordance with the characteristics of the board before searching for a wiring route. By searching for a wiring route while recognizing the line length limiter, the length of line segments running on a specific grid point array is limited to a specific length or less, and the generation of parallel adjacent long line segments is suppressed. This has the effect of reducing the occurrence of crosstalk.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the invention, and FIGS. 2 and 3 show examples of application of the invention. In Figures 1 and 2, 1... Wiring control section, 2... Parameters, 3... Wiring grid madatsu, 4... Wiring prohibition data , 5...
... Existing wiring route data, 6... Wire length limiter generation unit, 7... Wiring section data, 8... Wiring route search unit, 9...・Wiring route data, 10・
... Line segment (already routed), 11 ... Line length limiter, 12 ... Line segment (route searching), and 13
・・・・・・Arrangement Z side (a) χ4 rb
) 171 No. 3

Claims (1)

[Scope of Claims] A wiring route search device that searches for a wiring route in a section requiring connection based on a wiring grid set on a board, comprising the following steps: storage means for storing whether or not a line length limiter for limiting the length of a line exists on a grid point; and means for limiting the length of a line segment that constitutes a wiring route including a grid point on which the line length limiter exists during a wiring route search to a specific length or less. Route searching device.