Efficient Trace Signal Selection for Silicon Debug by Error Transmission Analysis

In this paper, a technique is presented for selecting signals to observe during silicon debug. Internal signals are used to analyze, understand, and debug circuit misbehavior. An automated procedure to select which signals to observe is proposed to facilitate early detection of circuit malfunction and to enhance the utilization of hardware resources for storage. Signals that are most often sensitized to possible errors are observed in sequential circuits. Given a functional input vector set, an error transmission matrix is generated by analyzing which flip-flops are sensitized to other flip-flops. Relatively independent flip-flops are identified and a set of signals that maximally cover the possible error sites with given constraints are identified through integer linear programming. Experimental results show that the proposed approach can rapidly and precisely identify the nonconforming chip behavior and thereby can speed up the post-silicon debug process.