MVP: Minimum-Violations Partitioning for Reducing Capture Power in At-Speed Delay-Fault Testing

Scan shift power can be reduced by activating only a subset of scan cells in each shift cycle. In contrast to shift power reduction, the use of only a subset of scan cells to capture responses in a cycle may cause capture violations, thereby leading to fault coverage loss. In order to restore the original fault coverage, new test patterns must be generated, leading to higher test-data volume. In this paper, we propose minimum-violations partitioning, a scan-cell clustering method that can support multiple capture cycles in delay testing without increasing test-data volume. This method is based on an integer linear programming model and it can cluster the scan flip-flops into balanced parts with minimum capture violations. Based on this approach, hierarchical partitioning is proposed to make the partitioning method routing-aware. Experimental results on ISCAS´89 and IWLS´05 benchmark circuits demonstrate the effectiveness of our method.