A Graph-Based Approach to Power-Constrained SOC Test Scheduling

The test scheduling problem is one of the major issues in the test integration of system-on-chip (SOC), and a test schedule is usually influenced by the test access mechanism (TAM). In this paper we propose a graph-based approach to power-constrained test scheduling, with TAM assignment and test conflicts also considered. By mapping a test schedule to a subgraph of the test compatibility graph, an interval graph recognition method can be used to determine the order of the core tests. We then present a heuristic algorithm that can effectively assign TAM wires to the cores, given the test order. With the help of the tabu search method and the test compatibility graph, the proposed algorithm allows rapid exploration of the solution space. Experimental results for the ITC02 benchmarks show that short test length is achieved within reasonable computation time.