D-extended Petri nets for simulating of digital devices

Abstruct: The paper presents D-extended Petri nets, a specific variant of Place/transition nets with inhibitor arcs that are structurally restricted in a way that implies safety. This class of nets is shown to be able to represent basic boolean functions as NOT, NAND, NOR and to build elementary flip flops like TT. A notion of time is added in a way, that handles conflicts among enabled transitions by a non-deterministic selection of one transition to fire and disabling others. Enabling times are not memorized, so the next time the discriminated transition becomes enabled again, it must wait the whole duration before it can fire. The paper proposes the use of the presented class of Petri nets in the design of digital circuits. Key words. Digital circuits, typical structures of models, combinatorial and consequent logic, the models of functional elements of digital devices