The development control information tools for PADS

Valery Klimenko Stepanovich (Ph.D.)

PADS-program (Logic, Layout, Router), developed by Mentor Graphics for the design of printed circuit boards (PP), a Basic Scripts Editor, to write, edit and immediately comply with Visual Basic-like programs (scripts), which provide rapid access to information on sites of the project, and sometimes to deliberately manipulate the characteristics of these objects. For example, the script is in a few lines can be obtained on the screen or write to file a list of components PP (all, select, chosen on any other grounds), including its coordinates, shape, etc.

The availability of Basic Scripts Editor and Automation as part of OLE (Object Linking and Embedding) significantly enhances the PADS-programs and allows, in particular, to solve specific tasks that are not integrated into the PADS standard tools. These specific requirements are again and again, they are supplemented and modified. Their flow is due to many factors. This improvement or modification of PP production technology, and analyzes electromagnetic compatibility, and the results of laboratory and industrial testing samples of electronic devices, and others.

But nezavimo from what the specific requirements for the PP due formal approach involves compulsory documentation. The existence of such documents and the ability to access it opens a new direction in creating tools in the form of scripts (or independent programs), significantly upgraded design process PP. Specifically, this means a script through the connection between PADS-program and prescriptive documents, which in one way or another to facilitate compliance. As a prescriptive documents may be, for example, Word-, Excel-, text files, e-mail ... Correct references to the names of electrical components or circuits PP allows using scripts, for example, quickly find and select the appropriate components and circuit design and oversee the real design solutions. Or, conversely - when selektirovanii PP objects to the requirement to find him in prescribing documents and verify compliance. This dramatically increases the effectiveness of the project and increases their quality.

The second important development PADS-scripts due to the fact that, besides designing new cards, a large amount of design work is in the processing of previously designed electronic devices. Typically, it is required either to meet the specific requirements of the new customer to previously developed device, or simply in connection with the modernization of equipment ... In this case, when designing a new version of PP greatly assisted by scripts, allowing "podglyadyvaniya" constructive decisions in previous projects.

It should be noted that embedded tools PADS-programming in a much more focused on the development of new cards than for processing PP with the previous design. The only standard tool for PADS, allows you to compare projects is Compare.

Our development Scripts PADS-not only the results generated Compare, but linked projects: the new and previous. This is many times reduces the time spent on sravnivanie and analysis of design decisions.

Comparing the two areas described PADS-scripts and shows their common feature: the creation of linkages between relevant projects and complementary programs - whether with specific requirements, whether compared with the project. This sign (that is, the presence or absence of contact) is the first to set up our classification and control information PADS-tools.

Of course, that if the requirements for PP does not change and are repeated from project to project, as well as when they refer to all the objects of a particular type, with an additional link PADS program (or programs) may be deleted. A more rational use of specialized tools is, only monitors compliance with certain requirements. These tools have traditionally dominated among developed script.

It should be noted that the mere communication PADS-project with an additional program like Excel or Notepad - a well-known and widely used reception, present even in the examples for Mentor Graphics PADS. He, however, always (or usually) applies only to display the results in the performance of the script, but not for questioning the documents in order to obtain additional information necessary to analyze the project through the PADS-tool. So, speaking of communication, as a sign of the classification created by our tools, means the only such relationship with additional programs, which is used to survey documents.

In addition to the above mentioned, we have also developed PADS-tools avtomatiziruyuschie some design work. However, the description of those tools is beyond the scope of this article.

The second sign is created classification definition of the object visualization, that is selektirovaniya on the screen, or the inclusion of the list (for example, further selektirovaniya for). At best, this can be identified using a script error on the board, often the same - only the critical place, subject to additional controls. In the case of comparing projects - are interested in designer or the distinguishing feature of PP.

C view of what opportunities provided PADS-script after the detection of error or indication of the criticism of the design, you can divide created tools for adjusting design (automatic or semiautomatic) or to alter only directly designer (third feature of the proposed classification).

It should also consider that possibility scripts not unlimited, as well as to monitor only those objects and their characteristics, which PADS provides for the use (ActiveX Automation Members). There is, unfortunately, a large number of objects and their properties, accessed through OLE and the Basic Scripts Editor impossible. For example, the contours of the components (Keepout) in the number of sites available. The same applies to change the nature of objects: the majority of them can only be read but can not modify (To be more precise, the change in the characteristics of all, perhaps, but it is rather cumbersome and by Mentor Graphics of any considerations, strictly speaking Not provided).

Reviewing the documents to the specific requirements of the project PP (the so-called Designe Rules), is easy to identify reserves of more efficient use of PADS-developed tools. The mere mention of names of components or circuits in Designe Rules allows you to quickly find your site on the board or in the scheme. This is already done. But reserve PADS-performance instruments concluded in an analysis of context, the reference facilities. Unfortunately, more often than not this context is not standardized and not systematized. For example, the requirement as close as possible placement of components to certain conclusions integrated circuit may be formulated in different places Designe Rules different definitions, not to mention that the name of the findings of the integrated circuit are unlikely to be always correct and applicable to the analysis of context. Improving standards for Designe Rules and compliance allows you to create a more "intelligent" PADS-tools and reduces the cost of designing PP.

When increasing the number of special scripts, constantly used in designing the PP, there are difficulties in using them because PADS is not possible to simultaneously perform two or more scripts. Must be the end of script to start the next, despite the fact that the first would be required immediately after the second, significantly reduces interest in using them. In addition, when executing scripts cease to function F-keys on the keyboard.

With this in mind, Mentor Graphics provides projects PADS-tools, working as independent programs, each of which is associated with PADS. For their creation can be used, for example, Visual Studio. Along with the possibility of the parallel use of several such tools as well as functions of F-keys, increasing the speed of the tools and software codes are invisible and inaccessible to change (that is missing when using scripts). So we use Basic Scripts Editor, usually only for quick verification and implementation of the ideas of new tools. For practical use in the design of PP PADS-tools developed later as a separate program.

Considering the situation more globally, we can say that the creation of additional PADS-tool is actually PADS-adjustment programs to the specific requirements of businesses related to design PP. In addressing such challenges is important holistic approach. In particular, he suggests a preliminary analysis of specific requirements, and then agreed to draft separate instruments harmoniously integrated into the overall concept. For the PADS-user is ultimately reflected in a convenient supplementary Tools-menu for the developer programs - to exclude the need for often-repeated in various versions of the same functions and to shorten the duration of PADS-creation tools, and for the customer - in savings.