On X-Variable Filling and Flipping for Capture-Power Reduction in Linear Decompressor-Based Test Compression Environment

Excessive test power consumption and growing test data volume are both serious concerns for the semiconductor industry. Various low-power X-filling techniques and test data compression schemes were developed accordingly to address the above problems. These methods, however, often exploit the very same “don´t-care” bits in the test cubes to achieve different objectives and hence may contradict each other. In this paper, we propose novel techniques to reduce scan capture power in linear decompressor-based test compression environment, by employing algorithmic solutions to fill and flip X-variables supplied to the linear decompressor. Experimental results on benchmark circuits demonstrate that our proposed techniques significantly outperform existing solutions.