VLSI oriented design method of asynchronous sequential circuits based on one-hot state code and two-transistor AND logic

A novel design method for asynchronous sequential circuits based on two-transistor AND logics and one-hot code state assignment is presented. Memory elements for internal state code are set-reset flip-flops with set and reset control circuits composed of two-transistor AND logics, which have only two transistors on each conduction path to the ground. Circuits are critical race free, hazard free and compact compared with related works. It is also shown that the present method gives the smallest circuits in terms of numbers of transistors for large asynchronous machines as specified by transition tables of more than 40 cells