@techreport{R-92-03, TITLE = {Functional Level Testability Analysis for Digital Circuits}, AUTHOR = {Raimund Ubar}, YEAR = {1992}, NUMBER = {R-92-03}, INSTITUTION = ida, ADDRESS = idaaddr, ABSTRACTURL = {/publications/cgi-bin/tr-fetch.pl?r-92-03+abstr}, ABSTRACT = {The paper presents a general approach for calculating controllabilty and observability measures. These measures are applicable to sequential and combinational circuits represented at the functional level. The developed methods and algorithms are based on alternative graphs which are an extension of binary decision diagrams where instead of only Boolean, also integer variables and functions are used. The algorithms developed for AGs are general and can be easily adjusted for calculation of different types of testability measures. It is shown that the controllability and observability cannot be treated as absolute measures because they are very tightly related to a used testing method. The testability measures for different testing environments are defined and their calculation is supported by corresponding algorithms. A presented formula for the calculation of the combinational controllability allows to regard initiability and different heuristic controllability measures as components of the probabilistic controllability. }, IDANR = {LiTH-IDA-R-92-03}