state diagrams of flip flops

state diagrams of flip flops

1. Flip Flop ' s State tables and State diagrams By Unsa Shakir

2. A state diagram is a diagram used in computer science to describe the behavior of a system considering all the possible states of an object when an event occurs . State diagrams are often used to represent the dynamic behavior of systems. The circles in a state diagram correspond to states of the system being modeled, and the arcs connecting those circles correspond to the events, which result in transitions between those states. State diagram

3. The state table representation of a sequential circuit consists of three sections labeled  present state ,  next state  and  output . The present state designates the state of flip-flops before the occurrence of a clock pulse . The next state shows the states of flip-flops after the clock pulse The output section lists the value of the output variables during the present state State Table

4. Example:

5. State Table

6. State Diagram

7. The Basic SR Flip-flop The Basic SR Flip-flop with clock SR FLIP FLOP

8. state table The state diagram 1 x0 01 0x 10 Q(t+1) = S + R'Q(t) S R Q(t+1) Q(t) 1 1 1 1 1 x c ha r ac t er i s t i c equation State diagram

9. JK-FLIP FLOP

10. J-K FLIP FLOP TRUTH TABLE S=J.Q’ R=K.Q

11. State Diagrams: J-K state table The state diagram 1 x0 x1 0x 1x Q(t+1) = J Q(t)' + K' Q(t), or Q(t+1) = J Q(t)' + K' Q(t) + J K' J K Q(t+1) Q(t) 1 1 1 1 1 Q(t)' c ha r ac t er i s t i c equation static hazard!!

12. D-FLIP FLOP

13. J=Q D-FLIP FLOP TRUTH TABLE

14. state diagram 1 1 1 Q(t+1) = D c ha r ac t er i s t i c equation State diagram state table

15. T-FLIP FLOP

16. state table state diagram 1 1 1 Q(t+1) = TQ(t)' + T'Q(t) = T  Q(t) 1 1 Q 1 c ha r ac t er i s t i c equation State diagram T 0 1

17. Summary of the characteristic equations Flip-flop Characteristic Equation D Q(t+1) = D T Q(t+1) = T  Q(t) SR Q(t+1) = S + R' Q(t) JK Q(t+1) = J Q(t)' + K' Q(t) CHARACTERISTIC EQUATIONS

18. Summary of the excitation tables For each state transition Q(t)  Q(t+1 ) Q(t) Q(t+1) D T SR JK 0x 0x 1 1 1 10 1x 1 1 01 x1 1 1 1 x0 x0 Excitation tables