Cover Approximations for the Synthesis of Speed-Independent Circuits

This paper presents a novel methodology for the synthesis of speed-independent circuits from Signal Transition Graphs (STGs). The pursued objective is to avoid the derivation of the reachability graph to calculate the logic equations for the outputs of the circuit , hence overcoming the state explosion problem. The circuit synthesis is performed by only analyzing the str ucture of the STG with efficient polynomial algorithms. The proposed techniques are applied to any live and safe free-choice STG providing sig- nificant improvement over previous state-based and structural methods. The same methodology can be directly extended to more general STGs. The developed structural synthesis tool has synthesized STGs (some of them being non-free-choice) with over 1012 markings.