Issue No.02 - March-April (2008 vol.25)
Chao-Wen Tzeng , National Tsing-Hua University
Shi-Yu Huang , National Tsing-Hua University
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/MDT.2008.55
This article presents a universal-multicasting scan architecture for test compression. By universal multicasting, the authors mean that a specific test pattern can be multicast to a set of any desired scan chains as long as they are compatible. It does require the addition of some extra control bits padded to the compressed test patterns. However, by incorporating techniques such as control pattern encoding, skipping, and partial data reuse, the authors demonstrate that the control overhead can be reduced to a modest level. This method improves the test compression ratio substantially over the recent software-defined multicasting methodology, most notably the segmented addressable scan (SAS). Experimental results indicate that up to 51x test compression ratio in both test data volume and test time can be achieved for a real design with a 1.3% care bit ratio in the test set.
test compression, DFT, scan test, broadcasting, multicasting
Chao-Wen Tzeng, Shi-Yu Huang, "UMC-Scan Test Methodology: Exploiting the Maximum Freedom of Multicasting", IEEE Design & Test of Computers, vol.25, no. 2, pp. 132-140, March-April 2008, doi:10.1109/MDT.2008.55