Scaling controlled random tests based on Hadamard matrices

Objectives. The problem of constructing controlled random tests is solved by two-dimensional scaling of initial templates using Hadamard matrices. The limitations of classical approaches to generating test patterns based on enumeration of candidates for test patterns are shown. With an increase in the threshold values of the difference measures of binary test patterns, the computational complexity of constructing such tests increases. The main goal of this article is to develop methods for constructing tests based on initial templates and their expansion to the required bit size based on the application of formal rules. Methods. For two-dimensional scaling of initial templates with specified Hamming distance thresholds, Hadamard matrices and the Sylvester recursive procedure for their construction are applied. The experimental research employed the method of statistical trials. Results. It is demonstrated that methods for constructing controlled random tests based on templates can be viewed as a procedure for scaling controlled random tests to the required bit size. Both templates characterized by the minimum bit size of patterns and any controlled random tests are used to construct the desired tests. The procedure itself is characterized as one-dimensional scaling, which increases the bit size of patterns while maintaining their quantity. To simultaneously increase the bit size and quantity of test sets, a method based on two-dimensional scaling of templates using Hadamard matrices is proposed. This allows for the construction of controlled random tests without the labor-intensive process of enumerating candidate test patterns and computing their difference measure values. It is shown that the unique orthogonality property of Hadamard matrices, as their order increases, enables achieving ratios of the average Hamming distance between test patterns to their bit size close to 1/2. It is noted that the characteristics of the initial templates do not significantly affect the characteristics of the resulting tests constructed using Hadamard matrices obtained through the Sylvester recursive procedure. The feasibility and efficiency of the proposed approach to constructing controlled random tests are evaluated for the case of testing memory devices. It is demonstrated that controlled random tests constructed using Hadamard matrices have significantly higher coverage capability compared to random tests. Conclusion. An approach for generating test patterns in the formation of controlled random tests using Hadamard matrices is considered. The proposed approach is based on two-dimensional scaling of initial templates using these matrices. It is shown that the use of various templates and their two-dimensional scaling allows for the construction of controlled random tests with the required bit size of test patterns and a larger number of them