4. (a) Use the three-step approach to analyze the circuit in Figure 4 (excitation/output equations, state/output table, and state diagram). Keep the state in numeric (non-symbolic) form. Assume that only lower order three bits (Qc, QB, QA) of the counter are used. Note that (Qc, QB, QA) is the present state, and (Q s the next state. The state table should also have columns for the internal excitation signals, including LD, C, B, A, in order to determine the state transi tions (b) What is the maximum system clock frequency? Be sure to show the critical path LSO8 LS139 G Y3 Y2 QAB QCA LS163 LD ENP ENT RCO LS139 QD G Y Y2 B YI QCA YO QA QB QB QB- QA QA CLR CLK