同海才 TONGJI UNIV →1 ninput x2- Z2 m output variables variables Xn Zm Combinational circut y1 Y k secondary k excitation variables y2 Y variables (present (next state) state) yk Yk Delay Delay Delay 2002 Prentice Hall.Inc. M.Morris Mano Fig.9-1 Block Diagram of an Asynchronous Sequential Circuit DIGITAL DESIGN,3e