Automated Testing of LS
Original Publication Date: 1982-Mar-01
Included in the Prior Art Database: 2005-Nov-11
Software Patent Institute
R. A. Rasmussen: AUTHOR [+3]
IBM General Technology Division
THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.
This record contains textual material that is copyright ©; 1982 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Contact the IEEE Computer Society http://www.computer.org/ (714-821-8380) for copies of the complete work that was the source of this textual material and for all use beyond that as a record from the SPI Database.
Automated Testing of LS.
R. A. Rasmussen,
IBM General Technology Division
Automated testing of today's complex LSI devices requires equally complex test equipment and pattern generation, but the process can be simplified by designing for testability.
An understanding of the LSI testing process must encompass the test objectives, the automated test equipment, the design of the product to be tested, and the software involved in generating and applying the test data. All of these topics are treated in this article, which is intended to extend Computer's previous tutorial on LSI design automation. ~ Emphasis is placed on advanced techniques for LSI device testing and test generation.
Much of the early work in advanced automated testing was done for the military; it included both checkout and repair of electronic systems. In the mid-1950's this operation typically involved a special-purpose tester which was hard-wired or tape programmed to automatically detect and diagnose defects in missile or airborne avionics systems. Since obsoleting a weapons system simultaneously obsoleted all its support equipment, the benefits of general-purpose test systems were quickly recognized. Thus, for a time, attention focused on development of a "universal tester" controlled by a "universal test language." Every year, symposia were dominated by discussions of new systems that overcame limitations of previous systems. These, in turn, were replaced the following year. Finally, the industry recognized that there are many different ways to perform testing and diagnosis, each with' advantages in particular situations, and that any test system capable of performing them all would be too expensive to proliferate for use in all applications.
The industry began using automated test equipment for logic circuitry almost as soon as such circuitry was produced in volume. The first test systems grew out of equipment originally designed for component (transistor, resistor, etc.) testing. Typically, they were hand- programmed for each individual logic circuit. Special-pur pose testers were developed for memories, which were generally exercised with a simpler sequence of tests than logic circuits but at a much faster rate. Other equipment developed for analog circuit testing usually required manual interpretation of an oscilloscope trace for GO/NOGO and diagnostic decisions.
Today, automated systems are available from many manufacturersP Most systems stress capability for testing one type of circuitry (logic, memory, or analog)...