# Patent

## Title
Integrated electronic design automation system

## Abstract

An electronic design automation system combines features of discrete EDA/CAD systems and manufacturing systems into a monolithic system to enable a layperson to efficiently design, construct and have manufactured a specific class of custom electronic device, namely a computer processing unit with embedded software. A Graphical User Interface (GUI) is provided as the front-end to a Computer Aided Design (CAD) server that generates sophisticated control and manufacturing instructions that are delivered to a fabrication supply chain, which produces a specified device that is then transported via managed logistics into inventory and ordering systems at vendors for delivery to a designated customer.

## Background
CROSS-REFERENCES TO RELATED APPLICATIONS
The present application claims benefit under 35 USC 119(e) of U.S. provisional Application No. 61/653,278, filed on May 30, 2012, entitled “Integrated Electronic Design Automation System,” the content of which is incorporated herein by reference in its entirety.


STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK.
Not Applicable
BACKGROUND OF THE INVENTION
This invention relates to electronic design automation and computer aided circuit design. More specifically this invention relates to the simplification of electronic circuit design such that a person without specific knowledge of circuit design could design and order a custom product and expect end-to-end integration of circuit design through manufacturing and delivery.
Electronic circuit boards provide the foundation of the electronics device industry: they essentially comprise “Printed Circuit Boards” or PCB (laminated layers of conductive material and an insulating substrate, where the conductive material forms traces or electrical signal pathways that connect components mounted on the outer surfaces) and electronic components such as resistors, integrated circuits, LED's, etc., which together form a functional circuit when provided with power connections and input and output couplings. Today, creating and building a custom circuit board requires the understanding of an electrical engineer with design expertise to select the components and arrange them conceptually before ordering the custom PCB and then orchestrating the supply of those components and contract manufacturers that assemble them. Although individual stages of this process may have been automated so engineers may be more effective and precise, to accomplish the entire process requires individuals skilled in several arts as well as an semi-automated supply chain for management of the part supply.
For example, an industrial designer may have an idea for a medical device that requires a microphone, a headset, pushbuttons, and artificial intelligence software for medical decision-making, inside a particularly shaped enclosure. With known state-of-current-art techniques, such a product design would require an electrical design engineer to develop an electrical schematic before passing the design to a board layout expert, and then submitting the design to a logistics or manufacturing group for entering data and ordering components.
Computers-On-Modules (COMs) have been developed that alleviate the burden of complex circuit design from original equipment manufacturers across numerous domains. A COM requires only externally applied power to become a functioning computer: wireless communication and software are encompassed within. Expansion boards provide a mechanism to provide power to the COM and can provide potential functionality to certain types of COMs. By designing an expansion board, an electrical engineer can add a selection of input and output connectors to suit custom design needs. Gumstix, Inc., the assignee of the present invention, manufactures and offers a selection of demonstrative expansion boards for sale, as well as documentation for designers to develop their own uses.
The concept of integrated end-to-end-design-to-delivery systems is not new. For example, within limits, consumers may customize motor vehicles by selecting options as a part of online ordering for manufacturing, and publications can be designed and delivered though on-line service offerings. An example of an integrated and versatile publication process is described in U.S. Pat. No. 6,717,686 to Farros et al. assigned to iPrint.com.
However, no fully integrated systems are known to exist to provide dedicated end-to-end-design-to-delivery. What is needed is a tool for use by an essentially untrained user allowing the quick design of electronic products that may include one or more computers-on-module, and that will order and thus ultimately manufacture and deliver the products to an intended customer.
SUMMARY
According to the invention, a system and method are provided that enable a layperson, namely an intended user/designer without detailed design knowledge, for designing, building and delivering custom application printed circuit boards that may use computers-on-module as board components among other board components, in which the user/designer employs an automatic schematic or layout design interface of a schematic design tool to generate a board design, the schematic design tool in turn providing information to further subsystems with all needed constraints so that the subsystems can perform a board layout without further intervention from the user/designer, and further can generate gerbers and manufacturing instructions directly to vendors, fabricators and board assemblers with minimal human intervention, thereupon enabling delivery of finished custom application boards to an intended customer.
By layperson it is meant a designer as an intended user who has minimal experience in or knowledge of design and function of electronic circuits, or someone without formal electrical engineering design training. More specifically, an electronic design automation system is provided that combines features of discrete EDA/CAD systems and manufacturing systems into an integrated system to enable efficient design, construction and delivery of a specific class of custom electronic devices, namely a computer processing unit with embedded software. A Graphical User Interface (GUI) may be provided as the front-end [using for example JavaScript on a web browser] to a Computer Aided Design (CAD) server that generates sophisticated control and manufacturing instructions that are delivered to a fabrication module, which produces a specified device that is then transported via managed logistics into inventory and ordering systems at vendors for delivery to a designated customer. In addition, downloadable simulations of the resulting devices may be provided, as well as 3-D images, mechanicals and Linux OS kernels customized to the specific devices.
The subject of this invention is a system that provides laypersons as herein defined, such as industrial designers untrained and generally unskilled in the art of electrical engineering, a tool to design systems by a drag and drop method that places functional collections of physical components onto a field, automates and validates the electrical connections, and if the connections are valid, to download software for the board, images of the board, or electronic and physical simulations of the board. The system according to the invention may employ localized computational power on a local a processor or processors and local volatile and nonvolatile program storage memory all functioning as a single platform operative to perform all input/output, circuit board specification, design, layout, administrative and manufacturing functions, or the system according to the invention may be distributed Alternatively, the system according to the invention may be distributed across a network, including local area networks and the Internet, employing functionalities at both local and remote sites, where the all input/output, circuit board specification, design, layout, administrative and manufacturing functions are distributed among various processors and memory components in communication via appropriate communication protocols well known in the art. Details of specific implementations of the invention are left to those of skill in the art.
Using the user interface features of the inventive system, herein called “Geppetto's Workshop,” or simply Geppetto, an intended lay user, typically an industrial designer without electrical engineering design training and expertise, can select placement of these components (including, if desired, one or more COMs) on a board and order the boards directly for delivery within a stated deadline.
Geppetto's Workshop is intended to provide a non-engineer the tool to design a custom computer of arbitrary dimension, including lights, switches, sensors and connectors. Nevertheless, Geppetto's Workshop does not require a COM to provide novelty design functions: its technique of connecting functional elements in a way that obviates the need for an electrical engineer is useful on boards of even modest complexity.
Important in ensuring delivery of a satisfactory electronic device is a method of examining the physical as well as the functional characteristics of the device. To this end, Geppetto's Workshop is configured to provide 3D visualization of the completed design in a browser window, and also to allow export of data for a user to import into external visualization tools. Geppetto's Workshop may also provide for download, data sufficient for characterization of device functionality to drive an external functional simulation of the device, e.g., in Qemu, an open-source device emulation system. This functional simulation could also be applied, within Geppetto's Workshop, to the 3D model to visualize device performance.
Important to the evaluation of a board after construction is the functional test to evaluate whether modules incorporate function as designed. Geppetto's Workshop is configured to export data sufficient to feed automated testing and functional validation of manufactured devices.
Devices intended to operate under software control generally require dedicated software development efforts. Geppetto's Workshop may provide for download of the software required to operate the device designed. The software may include the operating system software required, e.g. an Ubuntu or Angstrom Linux kernel and a root file system, to allow a user competent in Linux to direct the functions of the device.
The various aspects of the Geppetto's Workshop subsystem can run on one computer or be separated into processes spread over multiple systems. This includes systems coupled via local area networks, the Internet or using remote storage for local processors.
The invention will be better understood by reference to the following detailed description in conjunction with the accompanying drawing.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of an integrated design and manufacturing system according to the invention.
FIG. 2 is a flow chart illustrating client-side processing elements of the system according to the invention.
FIG. 3 is a flow chart illustrating server-side processing elements of the system according to the invention.
FIG. 4 is a block diagram illustrating administrative processing according to aspects of FIG. 3.
FIGS. 5A-5I are images illustrating displays for steps in the design process.



DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates features of an integrated circuit board design, layout and manufacturing system 10 according to the invention. The principal elements of interest are a functional design layout subsystem 120, a computer aided design subsystem 130 and an administrative subsystem 140, each with associated processors 122, 132, 142 and nonvolatile storage (program) memory 124, 134, 144 in which the programmed components of the subsystems reside. The operative element of the functional layout design subsystem is a functional layout design subsystem module, is also known as a schematic design subsystem, and associated with it is a user interface subsystem 14 and its interactive graphical display 17. The functional design layout subsystem 120 is part of “Geppetto's Workshop.” In addition in the computer aided design subsystem 130, there is an electronic design automation scripting subsystem or EDA tool 18 and which has its own or a shared central processing unit 132 and nonvolatile storage memory 134. The administrative subsystem 140, which has one or more of its own or a shared central processing unit 142 and nonvolatile storage memory 144 (in which the programmed components reside), comprises an enterprise resource planning subsystem 22, plus a series of often disparate manufacturing and delivery subsystems, including parts vendors 24, a fab vendor 26, a contract manufacturer 30 and a shipper 34, all of which may be built around and which has a central processing unit and nonvolatile storage memory.
An intended lay user is able to interact with the functional layout subsystem module 12 through the user input interface (UII) subsystem 14, such as a client-side web page maintained by the system 10 and accessible via a secure URL. The functional layout design subsystem module 12 operates as hereinafter explained in connection with FIG. 2 to invoke and indicate selected program modules added and removed, board size and connections made in communication with the user input interface subsystem 14. It may also prompt the user through the display 17 of the UII subsystem 14 as to validity of choices and possible alternatives. Pre-approved module design data about pre-designed and verified functional elements (modules), including schematics, layouts, EIS, and images previously prepared by an electrical design engineer employing an offline, typically remote, module design subsystem 13 are drawn from a module library 15 accessible by the functional layout design subsystem module 12. The schematic and layout data are directed to the functional design layout subsystem 12 while the corresponding images are directed to the UII subsystem 14 and an EDA tool 18. The intended user lays out the schematic design interactively using drag and drop operations. The resultant completed functional layout design is stored as CAD drawings, netlists, modules positions, board dimensions, connections designs and other data related to the requested product in a user design archive 16 containing later-accessible user data. All of the elements of the system can be provided through either a dedicated system or a distributed system as for example in a networked or web-based environment. Therefore the invention is understood to be not limited to any particular system configuration.
To produce a product, the intended user through the user input interface 14 instructs that the design be retrieved from the user design archive 16 and directed to a physical layout design subsystem, herein the EDA scripting subsystem 18, based on a commercially available electronic design automation (EDA) tool 18. The EDA tool 18, such as a CAD server, is responsive to instructions to execute specific operations according to customized scripts as hereinafter explained to produce a physical layout design and other output associated with the product from the output of the user design archive 16 generated by the functional layout design subsystem module 12. The EDA tool 18 is for example an Eagle design system from CadSoft Computer GmbH and CadSoft Inc., subsidiaries of Premier Parnell plc of England, OrCAD from Cadence Design Systems of San Jose, Calif. or offerings from Mentor Graphics of Wilsonville, Oreg.,
The EDA tool 18, operating on instructions directing the customized scripts, generates a physical layout dataset consisting of a gerber-file-format layout image, an X-Y data component list with locations on a board, a bill of materials, manufacturing instructions, instructional images, including 3D images and such other images, an electrical interface specification (EIS) and datasets needed for physical layout, manufacturing, costing, shipping and the like.
The physical layout dataset is optionally directed through a design verification module 20 to verify the design. If the prior subsystems have been properly configured to pretest the schematic and layout, then no extra verification is required. A commercially available EDA tool 18 typically incorporates a design verification module so that an additional design verification module 20 is not a necessary element.
The verified design is stored at least briefly for retrieval in a custom manufacturing data store 21. Each design is unique, so that such store must be renewed with each order. The verified design is directed automatically to the administrative subsystem 140, more specifically the output of the computer aided design subsystem 130 and the functional layout design subsystem 120, as stored at least temporarily as custom manufacturing data in the custom manufacturing data store 21 is directed to an electronic resource planning (ERP) subsystem 22, which contains further automated subsystems for generating design gerbers, for ordering, for issuing instructions for manufacturing and for accounting. (SAP Inc. and Oracle of California provide suitable ERP subsystems, and others are known.)
The ERP subsystem 22 is according to the invention configured to automatically order parts from parts vendors 24, get estimates from, and select and direct orders to, a chosen fab vendor 26 with the assistance of an estimate request subsystem 28 that solicits and collects information about optimal vendors, judged for example by favorable pricing, reliability, availability of parts and speed of delivery. The fab vendor 26 produces fabs, also described as printed circuit boards (PCB), and, along with the parts vendors 24, is instructed to deliver to a to a contract manufacturer (CM) 30 for assembly. The CM 30 assembles the parts and fabs to produce printed circuit board assemblies (PCBA) and top-level assemblies (TLA) representing the final circuit board. The assemblies and TLAs are typically final tested in a test module 32 by the CM 30 and, once approved, passed to a shipper 34. The shipper 24 delivers the assemblies to the customer or the designer as designated at the user interface 14. Thus, if the parts vendors 24, fab vendor 26 and contract manufacturer 30 have appropriately configured internal subsystems to respond to automated ordering, gerber execution and manufacturing and shipping, the process from selection of the functionality by the intended user of a particular design of a circuit board to delivery to a customer is automated.
There are a number of novel features that make such automation possible as hereinafter explained. Referring to FIG. 2, a flow diagram shows the processes surrounding the functional layout design subsystem 12. This function may be carried out via the user's web browser, or if desired, on a separate computer set up as a server. FIGS. 5A-5I provide illustrations of the results of the following steps.
The user input interface subsystem 14 includes a graphical user interface that provides the ability to tag, drag and drop icons or images representing stored module designs on to a displayed representation of a circuit board system to schematically design a circuit board by dropping images of the modules graphically onto a circuit board. This includes images of the board and images of one or more COMs in a workspace drawn from a palette with various categories of modules (FIG. 5A). The interface provides indicators that prompt the user as to allowable and disallowable operations in an interactive process until the design is completed (FIGS. 5B-5I). Drawing from the module library 15, the user drags and drops modules onto the board image on the display 17 (Step F1), adds modules (Step F2), whereupon the EIS requirements and the providers are updated (Step J1) and displayed (Step J2) and saved to a design buffer 8 (FIG. 2). The saved design is tested for validity (Step G) and if rejected, waits for the user to add additional modules and/or connections. If all EIS requirements are satisfied (Step G), the user interface subsystem 12 invokes a display of a “submit design” button (Step H1). When the submit design button is invoked (Step H2), data is drawn from the design buffer and the final design, namely the resultant EIS connections, module data (position and orientation) and board dimensions is serialized (Step H3) and stored as user data in the design archive 16. This information is employed by the functional layout design subsystem 12 to generate scripts as hereinafter explained that are shared with the EDA tool 18. Image data stored in the module library 15 is also available to the functional layout design subsystem 12 for creating scripts that run the EDA tool 18. When user data for a design is stored, the administrative operations may begin manufacturing steps.
Referring to FIG. 3, server-side operation in illustrated. Operation comprises three elements, an engineering function 13, data storage, and an administrative program as part of the EDA tool 18. It is necessary to have access to a predefined module library 15 of predefined elements or module data. To design a module library 15 containing such module data, a suitable engineer designs discrete functional elements, including COMs (some with preloaded operating systems, and/or preloader, boot, loader, kernel, and root/file system), power sources, connectors and ports, interfaces, such as USB and Ethernet, display interfaces, memory, and external storage such as flash memory. These are presented to the user as part of the palette (FIG. 5A).
At the outset, the electrical engineer must have or acquire a development kit for each module (Step A). A prototype is typically assembled from discrete components (Step B). The engineer defines an electrical interface specification (EIS) for the module (Step D) through the EDA design tool and file system. A program then exports the module data consisting of the module data, which comprises the schematic diagram, PCB layout, EIS and an image to the module library 15 (Step E).
Once a “build board” instruction is invoked, and after the design has been submitted (Step K), administrative operations employ module data from the module library 15 and user data from the design archive 16 to create an EDA auto-script (Step L). The EDA auto-script, or more generically the design instruction set, is then used to control the EDA scripting elements or EDA tool 18. The EDA tool 18 uses information from its compatible EDA library 17 to run the EDA auto-scripts lay out the physical structure of the circuit board and to produce the instructions to the manufacturing subsystems to build the circuit boards. More specifically, the EDA tool 18 automatically lays out the physical structure of the board with all modules and interconnections in proper orientation and input/output connections, from which it creates a set of computer aided design instructions. These operations are called auto placement and auto-routing. Thereafter the CAD tool 18 dispatches the CAD instruction with the data from the module library and design archive. Gerbers and associated indicia are generated and exported to be captured and stored (Step N) for use in the next phase, namely in the ERP subsystem, as previously explained.
FIG. 4 is a flow chart for explaining the use of scripts in the invention. The EDA tool 18 uses auto-scripts created by the Geppetto administration tool (Step L) to perform its tasks (Step M). While the details of the scripts are unique to the particular modules and allowable designs, there are four types of scripts that run in a CAD tool, namely a module-import script 40 to receive the auto-scripts by iterating over all modules included in the user data set and exporting position and schematic information about the board design, a build script 42 to draw the pre-routed modules in correct orientation and to draw the schematic with a table of contents, a routing script or set of schematic and layout files 44, and an export script 46 to export routed layout files as gerbers models and BOM 48.
Electrical Interface Specification
A module comprises a name, category, description, EIS and MFS (mechanical feature specification). The Electrical Interface Specification (EIS) is an interface standard associated with the invention that comprises buses (defined in the schematic), and the MFS comprises the lines indicating placement restrictions and points of interest (defined in the layout). Together they enable a lay designer to design printed circuit board assemblies. It forms the basis for the functional design layout subsystem of the invention. A module as used here is a set of meta-data exportable from the schematic diagram, PCB layout and filesystem path. It is stored in the module library 15 for use by the UII subsystem 14 and the scripting subsystem 18.
EIS buses are defined as a collection of signals (nets) that are functionally related and that conform to the naming scheme provided below to allow for automated connection. Buses must be classified as a requirement or a provider. In order for a design to be built, all EIS requirements must be connected to an EIS provider (with a corresponding set of properties). See pseudocode for matching algorithm details.
Naming Conventions
Buses:

    
    
        All nets to be used outside of the module must be connected to a bus.
        The Electronic Interface Specification is provided as a name-value encoded string that serves as the bus name.
    
    


The following properties are encoded in the bus name:

    
    
        NAME: A bus name that is unique to the module.
        TYPE: Does this bus provide or require some function from an external module.
        MATCH: For provide buses: the string; for require buses: the pattern.
        QTY: For provide buses: the capacity; for require buses: the amount of capacity used.
        IDX: If any nets on a bus are multiplexed, the index identifies the name for the net that corresponds to the bus function.
        LVL: The voltage level of the bus. Must be the same for a match to be made.
        WIRE: The priority for this bus when automatically connecting.
        ROUTE: The priority for this bus when automatically routing.
    
    


Examples

    
    
        NAME=VCC—1.8&MATCH=VCC—1.8&TYPE=R&QTY=1&IDX=1&LVL=1.8&WIRE=1&ROUTE=1
        NAME=I2C&MATCH=I2C*&TYPE=R&QTY=0&IDX=1&LVL=1.8&WIRE=1&ROUTE=1
        NAME=VCC—5.0&MATCH=VCC—5.0&TYPE=P&QTY=1000&IDX=1&LVL=5.0&WIRE=1&ROUTE=1
    
    


Nets:

    
    
        Nets connected to an EIS type provide should be named according to the following template:
        first-bus-name_first-function& . . . &last-bus-name_last-function
    
    


Example:

    
    
        GPIO0GPIO0&UART1_TX
        GPIO1_GPIO1&UART1_RX
    
    


The corresponding bus names would be:

    
    
        NAME=GPIO0 . . . IDX=1
        NAME=UART1 . . . IDX=2
    
    


NAME=GPIO1 . . . IDX=1 











The invention is expected to find a number of applications. +++
1) The Small Business Customer
COM customers typically fall into two categories, the first being a hobbyist or researcher building a prototype. The researcher may purchase a small number of COMs and expansion boards from Gumstix and modify them to meet specific needs. In many cases, the researcher, receiving outside funding for the product may become the second category, the volume customer. Volume customers may be expected to continue to buy COMs but design and manufacture a custom expansion board that meets their exact mechanical and electrical requirements. This represents a major challenge for businesses without PCB design expertise, and a lost opportunity for the COM manufacturer. Geppetto allows COM manufacturers to leverage the existing supply chain and infrastructure to provide custom PCB design and manufacturing services. The effect is two-fold for customers. They get the flexibility of a custom design with the reliability of an off-the-shelf design. It also reduces the OEM's list of suppliers.
2) The Artist
Electronic circuit board design is an expensive and challenging multi-faceted discipline. The Geppetto tool is an alternative to conventional Electronic Design Automation (EDA) tools that are focused on wire-level design. Using such packages, an engineer creates a symbolic representation of circuit elements and their interconnections. Once the schematic is finished, components and wires are mapped to footprints and traces on the printed circuit board drawing. Geppetto adds another layer of abstraction to the circuit design phase allowing users to simply drag and drop functional modules such as memory, USB I/O, networking, etc.
The symbolic representation of the modules provides the physical information (i.e. size, connector positions) a designer needs to integrate the layout phase. Buses, functional collections of wires, form the basis of an interconnection system that requires a minimal amount of user input. An automated system for connecting busses combined with functional modules completely eliminates the circuit layout phase from this tool. The net result is that an artist with a knowledge of consumer electronics can create a designer computer.
Process Example
1) Scenario
A user wants to build a computer for automobiles that can track position, monitor the vehicle health, and serve as a media center.
Requirements:

    
    
        Overo COM
        12V Power Input
        CAN bus for monitoring and controlling automotive subsystems
        GPS for trip tracking and navigation
        HDMI output for a monitor
    
    


Design

    
    
        Create a user account at a website
        Select File -> New from the menu bar—A design area and module library will appear
        In the module library, click on the Processors category
        Drag an Overo COM onto the blank PCB in the design area
        Click on the Power category and drag 12V power onto the board
        Add remaining modules
        Modules highlighted in red have unsatisfied bus requirements, click on each for a list of modules that can fill the requirement. The designer may have to add additional modules from the library.
        Position the modules and resize the board to meet mechanical requirements. One can drag them into place or, for greater precision, use the dimensioning tool.
        Select File -> Save
    
    


Preview
The preview menu will provide users with preliminary design data such as 3D renderings, software, and quotations.
5) Build
Place an order for the design created.
Accept delivery.
These last subsystem functions depend upon subsystems not directly under control of the Geppetto tool of the inventive system but which are intended to be modified to accept input and to be locally automated in accordance with the invention.
The invention has been explained with reference to specific embodiments. Other embodiments will be evident to those of ordinary skill in the art. It is therefore not intended that this invention be limited, except as indicated by the appended claims.

## Claims

1. A functional layout design subsystem for use with a computer aided design subsystem and an administrative subsystem, the functional layout design subsystem comprising:
a module library of pre-verified module data representing board-mountable electronic components or subsystems, the board mountable components or subsystems each having associated therewith a unique identifier for use by the computer aided design subsystem and the administrative subsystem, said board mountable components or subsystems each further corresponding to a displayable schematic representation described as a set of rules defining allowable inter-relationships between discrete functional electronic modules, said modules being defined by a combination of both (a) electrical connectivity rules linked to a schematic, and (b) mechanical placement rules linked to a layout, in order to form library elements of said module library,
the electrical connectivity rules comprising buses that are a collection of signals, and a label characterizing information carried on said signals, said information specifying the functional definition of the modules, thereby allowing for automated connection among the modules,
for use by a user having minimal knowledge of circuit design and function in the functional layout design subsystem, and wherein the layout design interface includes a drag and drop functionality for said board-mountable electronic components.

2. The system according to claim 1, wherein said design instructions for said circuit board include scripts for invoking operations in said computer aided design subsystem.

3. The system according to claim 2, wherein said scripts comprise instructions for interconnection among modules and subsystems, and for placement and orientation of modules and subsystems.

4. A method comprising:
retrieving a graphical representation of a plurality of functional electronic modules through a layout design interface subsystem having a display, wherein a user having minimal knowledge of electronic circuit design can define a circuit board function;
interactively designating physical placement of functional electronic modules on a representation of a circuit board, wherein the user is constrained by interaction with the layout design subsystem;
representing permissible interconnections among electronic modules and to power connections, input connections and output connections defined by
(a) electrical connectivity rules, the electrical connectivity rules comprising buses that are a collection of signals, and a label characterizing information carried on said signals, said information specifying the functional definition of the modules, thereby allowing for automated connection among the modules, and
(b) mechanical placement rules linked to a layout,
in order to form library elements, wherein the library elements are stored in an electronic archive in a form retrievable by the user;
to define design instructions of a functional electronic system formed upon at least one circuit board;
in response to the design instructions, causing a computer aided design subsystem to generate a manufacturing instruction set; and
in response to said manufacturing instruction set, causing an administrative subsystem to generate gerbers and manufacturing instructions for directing component vendors, board assemblers and shippers to manufacture and deliver according to specifications provided by an intended user as a functional circuit board in accordance with said manufacturing instructions and without further intervention from the intended user.

5. A method comprising:
retrieving a graphical representation of a plurality of functional electronic modules through a layout design interface subsystem having a display, wherein a user having minimal knowledge of electronic circuit design can define a circuit board function;
interactively designating physical placement of functional electronic modules on a representation of a circuit board, wherein the user is constrained by interaction with the layout design subsystem;
representing permissible interconnections among electronic modules and to power connections, input connections and output connections defined by
(a) electrical connectivity rules, the electrical connectivity rules comprising buses that are a collection of signals, and a label characterizing information carried on said signals, said information specifying the functional definition of the modules, thereby allowing for automated connection among the modules, and
(b) mechanical placement rules linked to a layout,
in order to form library elements, wherein the library elements are stored in an electronic archive in a form retrievable by the user;
to define design instructions of a functional electronic system formed upon at least one circuit board;
in response to the design instructions, causing a computer aided design subsystem to generate a manufacturing instruction set;
in response to said manufacturing instruction set, causing an administrative subsystem to generate gerbers and manufacturing instructions; and
employing the gerbers and manufacturing instructions to direct component vendors, board assemblers and shippers to manufacture and deliver according to specifications provided by an intended user as a functional circuit board in accordance with said manufacturing instructions and without further intervention from the intended user.