An efficient observability evaluation algorithm based on Factored Use-Def chains

Coverage evaluation is indispensable for simulate modern designs. In this paper, we present an efficient algorithm to evaluate observability coverage, which is based on Factored Use-Def chains (FUD chains), a data-flow analysis technique in compilers. With the strategy of enhanced FUD chains and event-driven analysis, this method has three advantages. First, it is significantly more computationally efficient than prior efforts to assess observability information. Secondly, it could be easily integrated into hardware description language (HDL) compilers or simulators. Finally, it is universal, and can be combined with controllability metrics, such as statement coverage metric (SCM).