BUILT IN SELF-TEST - ASSURING SYSTEM INTEGRITY

Testing electronic products is a crucial part of the manufacturing pro cess. This is particularly the case with today's complex products, in which even the smallest hardware defect can cause serious malfunctions . Integrated circuits being their Life on a wafer and are tested even before the wafer is diced into chips. The chips are subsequently packa ged and used in higher level electronics. Each manufacturing step can introduce new defects. However, as products become more complex, it be comes more difficult to use traditional external testing methods. This is the case because the integrated-circuit chips that that these prod ucts contain have an increasing number of deeply embedded core functio ns and are also operating at increasing frequencies. In addition, test ing equipment has bandwidth and performance limitations. In many cases , BIST, which moves critical test and measurement functions inside chi ps, can be used to conduct the necessary testing. BIST, which utilizes scanning technology, provides the stimulus-generation and response-pr ocessing capabilities necessary to test complex logic structures and e mbedded memory. Embedded BIST functions match the chip's capabilities, which can make them very effective testing mechanisms. Also, BIST sta ys with the chip throughout its life. Moreover, the addition of BIST f eatures to electronics hardware frequently doesn't significantly incre ase a product's size, cost, and production time, as was the case in th e past.