LabVIEW Reduces Wireless ASIC Device Characterization Report Generation Time

Author(s):
Jim Huddleston - G Systems Inc.
Robert Cornwell - G Systems Inc.

Industry:
Semiconductor

Products:
TestStand, LabVIEW

The Challenge:
Assisting our customer in the design and development of a wireless application-specific integrated circuit (ASIC) test platform based on TestStand and LabVIEW.

The Solution:
Using LabVIEW to combine several off-the-shelf components, so the software acts as a report scripting language, to make an automatic report generation tool.

Original Report Generation
Originally, users developed reports by interactively using several off-the-shelf components, including Excel for data manipulation and tables, OriginPro for graphs, and Adobe Acrobat for layouts. The user cut and pasted between these applications to generate the final report. Producing the reports took more than two man weeks for the first test of a particular ASIC device type.

At G Systems, we initially approached this problem through research by selecting an off-the-shelf product that could automate all aspects of the report generation process including:

• Extracting test data from a database
• Analyzing the data
• Producing high quality graphs with specific attributes
• Producing data in a tabular form
• Adding graphics and logos
• Outputting report as a multi-page PDF file with hyperlinks

While several products performed some parts of the report generation process, no single product performed them all. Also, due to the wide range of ASIC devices that needed tested, the report generation application had to handle an arbitrary number of test types and forcing conditions. Clearly, the solution needed to consist of more than a single off-the-shelf product and a powerful scripting capability.

After reviewing many possibilities, G Systems proposed using LabVIEW to combine several off-the-shelf components into an automatic report generation tool. In effect, we used LabVIEW as a report scripting language. LabVIEW was chosen for several reasons:

• LabVIEW is already used extensively in the ASIC test platform with TestStand
• LabVIEW includes many advanced data analysis tools
• LabVIEW provides an intuitive programming paradigm, even for a novice programmer
• LabVIEW provides a variety of standard interfaces to communicate with other software
• Graphical data flow programming provides an intuitive model for report generation
  

Our successful completion of this effort meant that the previous bottlenecks in the device testing process were no longer in the data collection and storage phase, but were in the process of generating formal reports based on the collected test data.

Components
Designers created the report generation tool as a LabVIEW toolkit that simplifies and abstracts access to the following underlying components:

PDFLib- (PDFLib GmbH) an ActiveX Component that provides functions for programmatically generating PDF files. Most PDF file functionality can be implemented including:

• Hyperlinks
• Imported graphics and pages from other PDF files
• Templates
• Vector graphics
• Tables

ComponentOne Chart2D- (ComponentOne LLC) an ActiveX component that produces presentation quality graphs. Features include:

• Output in vector or raster formats (EMF, JPEG, etc.)
• Full control of data formats, axes, fonts, etc.
  

LabVIEW Database Connectivity Toolset- a suite of LabVIEW function libraries, including one for performing database operations within LabVIEW. Features include:

• Direct interaction with local or remote databases
• High level functions for common database controls

The toolkit approach enables the engineer to design a report in LabVIEW for a particular device type in a few hours and then execute it with different sets of data as many times as needed. Thus, the ASIC device test turn-around time and cost significantly reduces. The toolkit also provides a higher degree of configuration ability and flexibility than any off-the-shelf reporting package.

Simplicity and Extensibility
To make the report generation process as simple as possible for the engineer developing a test report virtual instrument (VI), most of the details remain hidden from the user. Wherever possible, we used reasonable default behavior. For example:

• In tables, the column widths, row heights, font sizes, and pagination are automatically optimized
• Graph pages are automatically designed depending on the number of graphs wired into the RG_Add_Graph toolkit VI
• Graph titles, axis labels, scaling, legends, and other properties default to values based on the plotted data

Extensibility also played a major role as a key design goal for the toolkit. While it was impossible to anticipate all the future requirements of a toolkit of this type, it was possible to apply design principals that would allow users to easily add on new features without major modification to existing toolkit VIs.

Although the toolkit did not use a formal GOOP paradigm, it did use certain aspects of object-oriented design. For example, all graph VIs used a defined RG_Graph_Data typedef. Then, a variable of this type passed between graph VIs that manipulated its contents. In a simplified flow diagram depicting a graph from database data, the RG_Graph_Get_DB_Data VI gathers the basic test result data from the database based on the forcing conditions specified and generates an RG_Graph_Data variable. The RG_Add_Limits VI then adds additional information to the variable to represent limit lines. Next, the RG_Graph_Plot VI is used to plot the graph and make it ready for insertion into the PDF file.

This object-oriented, encapsulated design of the report toolkit enables extensibility. For example, when a user added a requirement to plot XY data from a comma-delimited file, modification of existing toolkit VIs was not necessary; only one additional VI was necessary. The only requirement was that the new VI output the XY data in the RG_Graph_Data format.

Also, when a need emerged for all the graphs on a particular page to have the same maximum and minimum values for the purpose of easier comparison of results, we only required one additional VI. We used a similar approach throughout the toolkit, so it could grow and evolve without the need for a major redesign.

Reducing Report Design Time with LabVIEW
By utilizing the flexibility of the LabVIEW development environment, G Systems created a LabVIEW scripting capability to combine multiple off-the-shelf software components into a powerful, report generation toolset. The LabVIEW graphical data flow programming provides the user with an intuitive paradigm for report scripting. Report design time has been reduced from two weeks to a few hours.

For more information, contact:
Robert Cornwell
G Systems, Inc.
Tel: 972-516-2278
Fax:972-424-2286
E-Mail: info@gsystems.com

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