N.Nicolici. Algorithms for state restoration and trace-signal selection for data acquisition in silicon debug. IEEETrans. on CAD,28(2):285–297

Abstract—To locate and correct design errors that escape pre-silicon verification, silicon debug has become a necessary step in the implementation flow of digital integrated circuits. Embed-ded logic analysis, which employs on-chip storage units to acquire data in real time from the internal signals of the circuit-under-debug, has emerged as a powerful technique for improving observ-ability during in-system debug. However, as the amount of data that can be acquired is limited by the on-chip storage capacity, the decision on which signals to sample is essential when it is not known a priori where the bugs will occur. In this paper, we present accelerated algorithms for restoring circuit state elements from the traces collected during a debug session, by exploiting bitwise parallelism. We also introduce new metrics that guide the automated selection of trace signals, which can enhance the real-time observability during in-system debug. Index Terms—Embedded logic analysis, silicon debug, state restoration, trace-signal selection. I