C.2008 Martin Macrae

The Internet provides a useful source of component information, but the data is unvalidated and not in any particular CAD-system format. The META system is orientated towards using files and data obtained from the internet in a concise and readable form, which compared with present systems that have CAD-data models

These functions are achieved by the following :

Maintain the part-data separate from its CAD implementation format

In order to do this librarian task will change from symbol-drawing, drafting and mapping, to validating and filtering data. Priority shifts from creating data to managing data that may have been input elsewhere, So many users have indicated they need control over a number of CAD system libraries, so managing the changes and controlling the versioning and distribution of data becomes a significant portion of the librarians task, META data is optimized for that rhole.

Having a neutral format that can be implemented at any physical location has also become a requirement as companies want to prototype, and production manufacture in different countries.

Nevertheless , such a system must be easy to use and have data that can be easily read, updated and managed.

The majority of new components used in designs consist of large processor, memory and programmable devices, these do not have swapping gates or pins. The need for discrete logic has decreased in proportion, so the need to create many parts with swappable pins or gates is no longer the main requirement for component tools. Designs have many very large devices, and the success of routing layout would not be critically affected if there were no swapping of gates or pins. A larger amount of design effort is devoted to verifying signal integrity, electrical rules instead of optimizing routing.

Where preliminary released part-information is available on the internet, as a data-sheet or model file, much of its schematic and package information is different from the users requirements. The signal -name listings however, are often used directly to name the connection points, as they are needed to be known by electrical as well as layout engineers. The librarian will have a company preferred standard for drawing, this can be 'procedurised' as a 'generating program', used by both a librarian and any engineer to make prototype component representations. This can reduced or eliminate the 'librarian bottleneck'.

Generators are an efficient way of making very-large pin count package representations and schematic symbols. Since most parts are now packaged in regular-shaped packages, these lend themselves to auto-generation. The international schematic standard (IEE/ANSI/IEC) can be used to define the functions of the symbol generator

Many companies purchase fragments of their CAD/ EDA systems without thinking too much about how the data is to be kept consistent across all the different databases and applications. However, creating data from a point source, where it is also managed, is a method to prevent errors between different users further along the design process. META Template management software, in contrast, produces its own tracking information from s single source to manage change control. These traverse links to populate CAD databases downstream and update them as required.

Since a company librarian will already have defined the company part-drafting standards, there is no reason why the company engineer cannot use data-building tools that are constrained by those rules to make local component representations as they require them, submitting the META-data for master-database re-use via the librarians control. This eliminates the Prototype/Librarian bottleneck while enforcing standards. Later on, as the design passes various control points, the authorized and validated representation can be substituted.

An established company master ECAD library may contain as much as 90% "legacy" data- That is representations that are no longer used for current designs but are maintained in the library in case an old design in reworked. Other part are kept as examples that would be copied and modified to make new parts symbols etc. Quite often a master library has to be migrated and translated to newer cad systems, where some of the usefulness of the data is lost in the translation. These two problems: maintaining legacy data and migration, currently take up much expensive effort. META-data is designed to ease these problems.

Principal META-data tool Functional priorities

Within a META-data system. only the minimum, concise data is maintained. A SAMPLE Component Signal File The co-ordinates of the exact positions of every schematic symbol detail, for example, is not needed to be stored witin a META componenet library system.

The data is expressed in the target-system application format when required EXAMPLE of how a generator makes a symbol the user does not maintain the application format version of the data.

A META-data system is prioritized on making the very-large pin-count parts that are now predominant in designs. Templates for smaller gate/pin swapping parts are also provided.

Large-pin count parts are usually distinct, (not sharing data with other parts, other than the package). Thus there are only PARTS and PACKAGES to be maintained as separate items.