Latency Analysis for Sequential Circuits

Abstract

Verifying correctness is a major bottleneck in today's circuit and system design. Verification includes the tasks of error detection, error localization, and error correction in an implemented design, as well as the analysis and avoidance of transient faults. For all those tasks, knowing when an assignment to signals becomes observable at the outputs and for how long it influences the system is important. In this letter, we propose a minimal and maximal latency measure for sequential circuits. This measure explains how long a circuit's state and outputs depend on input stimuli. Exact and heuristic algorithms are discussed to determine the measure. We evaluate the algorithms on state-of-the-art designs. Experimental results show how the measure provides insight into the behavior of circuit designs.