sequential- Circuit Models System Internally, the system generate the excitation variables, Eo to Ex, and state variables, So to Sx State Excitation Variables Variables ■ internal output M variables 0 a internal input variables X XCombinational logic System Input Variables System output Variables I0 In O0 Om S0 Sx M0 Ex State Variables Excitation Variables MX E0 ◼ Internally, the system generate the excitation variables,E0 to Ex , and state variables, S0 to Sx . ◼ internal output variables ◼ internal input variables