Flip-flops Chapter4 Sequential circuits
Flip-flops Chapter4 Sequential circuits
sequential- Circuit Models Combinational logic X Universal combinational circuit model ■ No memory units No feedback from logic outputs back to the inputs
Combinational logic X0 Xn Y0 Ym Universal combinational circuit model ◼ No memory units ◼ No feedback from logic outputs back to the inputs
equential- CirCuit Model System Input System Variables工, output Combinational「 Variables logic State Variables xcitation 0 0 EV ariables Universa sequential circuit model
Combinational logic System Input Variables System output Variables I0 In O0 Om S0 Sx M0 Ex State Variables Excitation Variables MX E0 Universal sequential circuit model
equential Circuit Model a Sequential implies that events are ordered in time that one event then another occurs separated by time Two types of sequential logic exist: D Synchronous sequential circuit a Synchronous sequential circuit is clocked O Asynchronous sequential circuit a Asynchronous sequential circuit is not clocked
◼ Sequential implies that events are ordered in time, that one event then another occurs, separated by time. ◼ Two types of sequential logic exist: Synchronous sequential circuit ◼ Synchronous sequential circuit is clocked Asynchronous sequential circuit ◼ Asynchronous sequential circuit is not clocked
sequential- Circuit Model System Input System Variables工n output ombinational Variables logic ■SetI{工o…n} SetO{O0…On} are external are external input variables output variables presented to Excitation M the system Variables E
Combinational logic System Input Variables System output Variables I0 In O0 Om S0 Sx M0 Ex State Variables Excitation Variables MX E0 ◼ Set I{ I0……In } are external input variables presented to the system. ◼ Set O{ O0……Om } are external output variables