Combinational trace signal selection with improved state restoration for post-silicon debug

Signal selection is the pre-silicon evaluation step which maximizes overall reconstruction rate of state elements. Due to its high complexity, recent efforts on signal selection has focused on sequential nodes in the circuit under debug. In this paper we propose a combinational signal selection algorithm which possibly selects combinational nodes of the circuit to maximize state restoration capability and achieve significant improvements (53% on average) compared to the state-of-the-art signal selection algorithms. To compensate for increase in problem complexity, we also propose a fast state restoration algorithm which offers significant improvement (38% on average) on simulation time over the state-of-the-art state restoration algorithms.