Analysis of Clocked Sequential Circuits

1. Analysis of Clocked Sequential Circuits

2. General Structure of a Mealy Machine Output depends on input as well as the state the circuit is in. (variable: state) Synchronize the input with clock when using Mealy machine.

4. Moore Machine Output depends on the state, but not the input.

5. Synthesis of Sequential Circuit • Start with a state diagram • Assign Binary Values to the States

6. State Diagram for Sequence Detector • Problem statement: • Design a circuit that detects a sequence of three or more consecutive 1’s in a string of bits coming through an input line

7. State Diagram of the Word Description Start with S0. if input is 0, stay in S0. if input is 1, go to S1. Once in S1 if input is 1, go to S2. if input is 0, go to S0. Once in S2 if input is 0, go to S0. if input is 1, go to S3. Once in S3, if input is 0, go to S0. if input is 1, stay in S3, set output to 1. Output is 1 when the circuit is in S3, 0 otherwise.

8. Going from the State Diagram to State Table 0 1 2 3 4 5 6 7

9. Assign Binary Value to the States 0 1 2 3 4 5 6 7 Use two flip-flops to represent states. Let x be the input And y be the output

10. Assign Binary Value to the States 0 1 2 3 4 5 6 7

11. Assign Binary Value to the States 0 1 2 3 4 5 6 7

12. Circuit Implementation

14. Sequence Detector Circuit Sequence Detector Random Number generator

15. Measurement Results B A x y clk