Enhancing Simulation Accuracy through Advanced Hazard Detection in Asynchronous Circuits
A fast and accurate simulator with elaborate hazard detection capabilities is vital for asynchronous circuits, not only for the purpose of design validation through logic simulation, but even more importantly for the purpose of test validation through fault simulation. Toward this end, we developed SPIN-SIM, a logic and fault simulator built around Eichelberger's classical hazard detection method, yet extended in various ways in order to overcome its limitations. More specifically, in order to improve simulation accuracy and hazard detection, SPIN-SIM 1) employs a 13-valued algebra for which it adapts Eichelberger's method, 2) maintains partial orders of causal signal transitions through relative time stamps, and 3) unfolds time frames judiciously to distinguish between hazards and actual transitions. Experimental results demonstrate that, at the cost of a negligible increase in computational time over Eichelberger's method, if any at all, SPIN-SIM achieves significantly more accurate logic simulation and, by extension, drastically more efficient fault simulation. Furthermore, while the proposed method was developed and is presented for the class of Speed-Independent circuits, it is easily extendible to various other classes of asynchronous circuits.
asynchronous circuits testing logic and fault simulation