JPH0512383A - Shield wiring path search system - Google Patents

Abstract

PURPOSE:To decrease the man-hours by automating a path search in the shield wiring of a printed wiring board. CONSTITUTION:A net whose wiring path needs to be shielded by a ground net (101). Virtual wiring width is found from the wiring width of the extracted net to be shielded, the wiring width of the net for the shielding, and the clearance between both the nets (104). The extracted net to be shielded is wired with the calculated virtual wiring width (105). The area obtained by subtracting the wiring width of the net to be shielded from the wired path is regarded as the wiring path of the ground net to be shielded (109). Consequently, the wiring path is determined so as to prevent interference to other nets and interference from other nets.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield wiring route search system for a printed wiring board.

[0002]

2. Description of the Related Art Conventionally, this type of shield wiring path is used for grounding a net that interferes with other nets such as a clock net or a net that needs to prevent interference from other nets. In addition, the wiring route of the ground shield net was determined by obtaining after determining the wiring route of the clock net or the like.

[0003]

In the above-mentioned conventional method, since there is not a sufficient free wiring area around the shielded net, the wiring path of the shielded net is corrected and the wiring path of the grounded net to be shielded is corrected. There is a drawback that it is necessary to obtain the search, which requires a large number of man-hours.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a wiring path for a net that needs to be shielded with a ground and a wiring path for a shielding ground net in order to prevent interference with or interference from other nets. A search method, a net extracting means for extracting a net whose wiring route needs to be shielded by the ground net, a wiring width of the extracted shielded net, a wiring width of the shielding net, and a shielded net A virtual wiring width calculation means for obtaining a virtual wiring width from the clearance between the shielded net and the shielded net; a wiring means for wiring the extracted shielded net with the calculated virtual wiring width; Register the area where the wiring width of the net is subtracted as the wiring path of the ground net to be shielded And a that wiring path registration means.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a flow chart showing the processing in one embodiment of the present invention.

First, in the processing box 101, a net that needs to be shielded is regarded as a net that requires a shield and is extracted.

In the judgment box 102, the processing box 1
It is determined whether or not all the nets having the shield request extracted in 01 have been processed. If there are unprocessed nets, the process proceeds to the processing box 103, and if they are all processed, the process proceeds to the processing box 114.

In the processing box 103, one unprocessed net is taken out, and the processing box 104 is proceeded to.

In the processing box 104, the wiring width of the net requiring shielding, the wiring width of the ground for shielding, and the clearance between the net requiring shielding and the ground net for shielding are checked, and the distance obtained by adding these is a virtual line. Determine as width.

In the processing box 105, the processing box 1
The net with the shield request extracted in 03 is regarded as a net having the virtual line width determined in the processing box 104, and a wiring route search with a line width thicker than the actual line width is tried.

In the judgment box 106, the processing box 1
In 05, it is checked whether or not the route search of the net for which the wiring route search has been attempted is successful. move on.

In the processing box 107, the net for which the wiring route search has failed and the shield is requested is recorded, and the process proceeds to the judgment box 102.

In the processing box 108, a net which has been successfully searched for a wiring route and has a shield request is corrected to a wiring route having an original wiring width and adopted.

In the processing box 109, the processing box 1
The portion of the wiring path having the virtual wiring width searched in 05 except for the original wiring width of the net having the shield request and the clearance with the ground net to be shielded is set as a part of the wiring path of the ground net.

In the processing box 110, in order to determine the equipotential of the net to be shielded, the terminal of the ground net closest to the part of the wiring path of the ground net found in the processing box 109 is found.

In the processing box 111, the processing box 1
A search for a wiring path between a part of the wiring path of the ground net obtained in 09 and the terminal of the closest ground net obtained in the processing box 110 is tried.

In the judgment box 112, the processing box 1
Check whether the wiring route search tried in 11 was successful,
If it fails, the process proceeds to the judgment box 102, and if it succeeds, the process box 113 proceeds.

In the processing box 113, the processing box 1
The wiring route tried in 11 and the wiring route obtained in the processing box 109 are connected and integrated as a wiring route of the ground net, and the process proceeds to the determination box 102.

In the processing box 114, the processing box 1
A wiring route search is performed by the conventional method for all the nets stored in 07, and a series of processing is completed.

FIGS. 2 (a) and 2 (b) show an image of a net that needs to be shielded, a ground that shields, and a clearance between them.

In FIG. 2A, between the terminals 1 of the nets that need to be shielded, the wiring width of the shielded net, the wiring width of the shielded net, and the clearance between the shielded net and the shielded net are shown. The state where the wiring route is searched by the added virtual line width 2 is shown.

In FIG. 2B, the wiring route 3 of the net to be shielded is determined from the state in which the wiring route is searched with the virtual line width 2 shown in FIG. 2A, and the terminal of the net to be shielded is determined. 4 shows a state in which the wiring route 5 of the net to be shielded including the routes up to 4 has been determined.

[0024]

As described above, the present invention is applied to a net that needs to prevent interference with other nets such as a clock net or a net that needs to be shielded with a ground to prevent interference from other nets. On the other hand, since the necessary ground shield wiring is automatically enabled, there is an effect that the ground shield wiring by the acquisition is reduced, and the wiring man-hours and correction man-hours for that are reduced.

[Brief description of drawings]

FIG. 1 is a flow chart showing processing in an embodiment of the present invention.

FIG. 2 is a diagram showing an image of a net that needs to be shielded, a ground that shields, and a clearance between them.

[Explanation of symbols]

 1 Net terminal that needs to be shielded 2 Virtual line width 3 Shielded net wiring path 4 Shielded net terminal 5 Shielded net wiring path

Claims (1)

Claim: What is claimed is: 1. A wiring route search method for a net which needs to be shielded with a ground and a ground net which shields the wiring route in order to prevent interference with other nets or interference from other nets. And a net extracting means for extracting a net whose wiring path needs to be shielded by the ground net, a wiring width of the extracted shielded net, a wiring width of the shielding net, and a shielded net and a shield. Virtual wiring width calculation means for obtaining a virtual wiring width from the clearance with the net,
A wiring unit for wiring the extracted shielded net with the calculated virtual wiring width and a region obtained by subtracting the wiring width of the shielded net from the routed route are registered as the wiring route of the ground net to be shielded. A shielded wiring route searching method comprising: a wiring route registration means.