JPH0495169A - Method for retrieving connection route in printed board - Google Patents

Abstract

PURPOSE:To shorten the time required for obtaining a prescribed connection route by retrieving the data of many kinds of connection routes by automatic wiring by a central processor, checking whether a swap is generated or not and obtaining a suitable connection route. CONSTITUTION:An automatic wiring method is applied with regard to parts loaded on a printed board, and a connection route is retrieved, while using a central processor. In this case, irrespective of whether the connection is complated or not, all connection routes having possibility are retrieved successively, and simultaneously, with regard to generation of a pin swap or a gate swap, its 'existence' is discriminated, and the connection route and the existence are stored, for instance, in a data base. subsequently, the route of non-existence is retrieved, and also, if plural routes thereof exist, its selection is executed by other means. In such a way, an optimal connection route can be obtained in a short time.

Description

[Detailed Description of the Invention] [Summary] Regarding a method for searching a wiring route on a printed circuit board while checking whether swap has occurred, the method is to search for a wiring route on a printed circuit board while checking whether swap occurs during wiring. By searching for routes in a short time,
The purpose is to provide a wiring route search method that quickly finds an appropriate route.In this method, a central processing unit searches for wiring routes on a printed circuit board by applying an automatic wiring method to components on the board. are performed sequentially, and the presence or absence of a pin swap or gate swap is simultaneously checked for each searched route to obtain a connection route in which the swap does not occur.

[Industrial application field]

The present invention relates to a method of searching for a wiring route on a printed circuit board while checking for the occurrence of a swap.

When using a central processing unit for automatic wiring processing on printed circuit boards, this is done based on circuit diagram information, but because the swap status is fixed, the wiring rate is not necessarily high. Therefore, there was a need to develop a route connection method that would increase the connection rate.

[Conventional technology]

In order to perform automatic wiring processing on printed circuit boards, it has become common to have circuit diagram information in advance as a database and to perform processing using a so-called CAD system using a central processing unit. Definition of the shape of components mounted on the board, arrangement of terminals, etc. and registration in the database are performed interactively. The circuit to be designed is divided so that it can be mounted on a wiring board, and the elements on the circuit diagram are further assigned to actual components. When arranging components, wiring should be considered when arranging them.
By repeating placement and wiring, we are getting close to the optimal state.

As a specific automatic wiring method, generally a reference grid is provided, component terminals and external connection terminals are always placed on the grid, and wiring is performed between the grids. The maze method and the line segment search method are known as methods for implementing this method.

[Problem to be solved by the invention]

When processing with automatic wiring methods, a condition called "swap" may occur. Swap refers to gate swap or pin swap, and the former is as shown in Figure 2, when it is part of a large-scale integrated circuit, 1°2 is an inverter, 3-6 are terminals, 7
indicates a chip, and normally, predetermined wiring is performed so that the inverter 1 is operated by terminals 3 and 4. At that time, it is normal that no wiring is performed for the inverter 2. However, when wiring from terminals 3 and 4, if there are obstacles such as other wiring on the board and it is not possible to connect the wiring directly from the terminals to the inverter, this simply means that the wiring is not possible and the next wiring The process was proceeding as if asking for. Even if wiring is possible using the terminal 5.6, it is determined that the process is impossible at the above stage. That is, only the wiring between the terminals 3 and 4 and the inverter 1 is included in the database, and no other related information is included. It is not always necessary to use terminals 5 and 6 immediately after starting to find the next wiring. In this way, even if the inside of the chip 7 becomes in a state in which wiring is not possible to the gate J, and wiring can be made by changing the connection with another gate circuit, conventionally, the replacement process is not performed.

This state is called a "gate swap." Conventionally, this swap status was fixed for printed circuit boards that were to be automatically routed.

Similarly, pin swapping refers to a state in which wiring is not possible with respect to external connection terminals or connection pins with internal circuits of the chip.

When there is an obstruction as mentioned above, in some cases correction work may be required to rewire the wiring partially by hand, which would take too much time to search for the desired wiring route. became. It is said that products that require a lot of manual labor have a low wiring rate.

The purpose of the present invention is to improve the above-mentioned drawbacks, and to quickly find a suitable route by searching for a large number of routes in a short time while checking whether or not swapping occurs during connection as a connection route on a printed circuit board. The purpose of this invention is to provide a method for searching for connection routes.

[Means to solve the problem]

In order to achieve the above object, the present invention has the following configuration. In other words, in a method in which a central processing unit searches for connection routes on a printed circuit board, routes are sequentially searched by applying an automatic wiring method to components on the board, and each searched route is checked for occurrence of pin swaps or gate swaps. This is configured by simultaneously checking the presence or absence of the swap and obtaining a connection route in which the swap does not occur.

[Effect]

The conventional automatic wiring method is applied to the components mounted on the printed circuit board, and the process of searching for wiring routes using the central processing unit begins. At this time, all possible connection routes are sequentially searched, regardless of whether the connection is complete or defective. At the same time, regarding the occurrence of pin swaps or gate swaps, the presence or absence can be immediately determined, so the connection route and the presence or absence are stored, for example, in a database.Next, a null route is searched, and if there are multiple such routes, other If the selection is made by means of this method, the optimum connection route can be found in a short time.

〔Example〕

As described in the above "Operation" section, the present invention can perform processing in accordance with the following embodiment, instead of first sequentially searching for and selecting a large number of connection routes. That is, FIG. 1 is an operational flowchart showing a preferred embodiment of the present invention. In FIG. 1, 8 is a data library of the CAD system, 9 is a circuit information database, and 10-1
．． 10-2-- is the wiring result database 1, 2...
・Indicates. S1 to S7 indicate operation steps 1 to 7 of a central processing unit (not shown). Initially, at 81, various information such as internet information is received by the data library 8 and database 9, and automatic wiring is performed. This process relies on conventional automatic wiring algorithms. When there is no more wiring to be done,
The wiring results are stored in the wiring result database 10-1.

Next, at 82, it is checked that there are no unwired lines.

If there is any unwired wire, it is checked in S3 whether or not a swap has occurred. If there is no unwired wire, the wire will be 100 in S4.
% completed. If there is a swap, a possible wiring change process such as wiring replacement is performed in S6. The swap flag is counted up in step 87 to indicate that the wiring process has been performed. Then, regarding the wiring change processing described above, the results are stored in the wiring result database 10-
Store in 2. Next, it is checked in 82 that there are no unwired lines for the new wiring. If there is any unwired wire, the process advances to S3 to check whether a swap has occurred. This process is repeated until no swap occurs. In this case, the final result will be the desired connection route.

〔Effect of the invention〕

In this manner, according to the present invention, data on many types of connection routes are searched by the central processing unit through automatic wiring, and a suitable connection route is obtained by checking for the occurrence of a swap. Since a large amount of data is obtained in a short time through processing by the central processing unit, the time required to obtain a predetermined connection route is also short.

Naturally, one with a high wiring rate is selected.

[Brief explanation of the drawing]

FIG. 1 is an operation flowchart showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram of "swap". 8...CAD system data library 9-Circuit information database 10-1.10-2...Wiring result database Patent applicant Fujitsu Limited Agent Patent attorney Eisuke Suzuki Figure 1

Claims (1)

[Claims] A method for searching wiring routes on a printed circuit board by a central processing unit, in which routes are sequentially searched by applying an automatic wiring method to components on the board, and pin swapping or gate processing is performed for each searched route. A method for searching a wiring route on a printed circuit board, comprising simultaneously checking whether or not a swap occurs to obtain a wiring route in which no swap occurs.