Test data compression based on input-output dependence

We use the fact that outputs of a large circuit depend on proper subsets of the circuit inputs to provide test data compression on the input side. The compressed input test data consists of patterns of length equal to the maximum number of inputs on which an output depends. This is typically smaller than the number of circuit inputs. A distribution block expands every input pattern into several test patterns for the circuit, one test pattern for every input pattern and input subset. We present experimental results to show that significant compression can be achieved by the proposed approach while maintaining complete fault coverage.