Enhancing high-level control-flow for improved testability

In this study, we present a controllability measure for high-level circuit descriptions and a high-level synthesis-for-testability technique. Unlike many studies in the area of high-level synthesis for testability that focus on improving the testability of data paths, the objective of our approach is to improve the testability of synthesized circuits by enhancing the controllability of the control flow. Experimental results on several high-level synthesis benchmarks show that when this approach is used prior to logic synthesis, a shorter ATPG time, a smaller test set, and better fault coverage and ATPG efficiency are often achieved. Implementation of this technique requires minimal logic and performance overheads and allows test vectors to be applied at clock-speed.