A hybrid method for segmented test data compression
Lung‐Jen Lee, Wang‐Dauh Tseng, Yi-Yu Liu · Journal of the Chinese Institute of Engineers · 2014
This paper presents a hybrid compression method for scan-based testing. Four distinctive compression techniques, i.e. frequency-directed run-length codes (FDR), inverting FDR, option coding technique, and optimal selective Huffman code are selected for compression of a given test set. To lift the potential compression limit, we properly cluster scan cells to classify test data as four subsets respectively, by majorities of 0s, 1s, Xs, and a roughly equal number of 0s and 1s to match specific properties of the compression techniques. Segments are then, respectively, compressed by the technique that fits best to achieve an overall good compression effect. Experimental results for the larger ISCAS’89 benchmark circuits show that up to 69.9% of average compression ratio and significant test application time reduction can be achieved.