An improved test access mechanism structure and optimization technique in system-on-chip

This paper presents a new test access mechanism (TAM) architecture and optimization method based on an improved flexible-width test bus. The method is first to set up the test time lower bound that is not depends on TAM architecture, then to construct a bus assignment that makes test time up to the lower bound. We present experimental results on our improved flexible-width test buses for four benchmark SOCs. Experiment results in a significant reduction of the test time, and is better than the proposed traditional methods in test time.