A New Wrapper Scan Chain Balance Algorithm for Intellectual Property in SoC

Recent patents and progress on scan chain balance algorithms have been reviewed. With a significant increase of the SoC (System on Chip) integration and scale, the test time of SoC increase dramatically, and this makes the test cost of SoC grow rapidly. In order to reduce test cost and expense, the paper proposes an OBBO (Opposition-based learning and Biogeography Based Optimization) algorithm and designs wrapper scan chains for the IP(Intellectual Property) using OBBO algorithm, which can make wrapper scan chains equilibration so that we can make the test time of IP be minimum. The new method is a random optimization algorithm which combines BBO (Biogeography Based Optimization) algorithm with OBL (Opposition-based learning). By using migration operation, mutation operation and OBL operation, we achieve a balance between different wrapper chains so that we can shorten the wrapper scan chain which is longest. Experimental results show that OBBO can obtain shorter longest wrapper scan chain in most case and at the same time the convergence speed can be faster.