Term trees in application to an effective and efficient ATPG for AND-EXOR and AND-OR circuits.

A compact data representation, in which the typically required operations are performed rapidly, and effective and efficient algorithms that work on these representations are the essential elements of a successful CAD tool. The objective of this paper is to present a new data representation—term trees (TTs)—and to discuss its application for an effective and efficient structural automatic test-pattern generation (ATPG). Term trees are decision diagrams similar to BDDs that are particularly suitable forstructure representation of AND–OR and AND–EXOR circuits. In the paper, a flexible algorithm for minimum term-tree construction is discussed and an effective and efficient algorithm for ATPG for AND–EXOR and AND–OR circuits is proposed. The term trees can be used for many other purposes in logic design and in other areas—for allpurposes where compact representation and efficient manipulation of term sets is important. The presented experimental results show that term trees are indeed a compact data representation allowing fast manipulations. They form a good base for algorithms considering the function’s and circuit’s term structures.