ENEE 206

February 24, 2004

Laboratory 6 - Sequence Analyzers

A. Lab Goals

B. Background Reading

Read about:

C. Definitions

D. Laboratory Equipment

E. New Hardware

F. Circuit Analysis

What procedure do we follow to design the sequence detector?
  1. First, we determine the number of states and draw a state diagram.

  2. Then we build the state table and we look to see if any reduction in the number of states is possible.

  3. Based on the type of flip-flops we use, we make transition tables, simplify the circuitry with K maps, and finalize the logic and wiring diagrams.
There are four distinct states for our sequence detector, which are labled A - D.
  1. State A is the state we arrive at any time X = 0, because that means we currently have no consecutive ones.

  2. The first "1" brings us to state B with zero output.

  3. The second "1" brings us to state C with zero output, and

  4. the third consecutive "1" brings up to state D with zero output.
    • We should think of states A, B, and C as having 0, 1, and two consecutive ones(11), respectively, but state D as "three or more consecutive ones."

    • Once in state C, if the next input is X = 1, we stay in state D and output a one.

    • In any state, if the input is X = 0, we immediately go back to state A and output zero.
State Diagram, State table

See more state diagrams for 1001 and 1011 sequence detectors.

The state table which shows the proper transitions is indicated in Fig. 6.4.

Sequence detector

Laboratory 5 Description


To build a synchronous sequential circuit with one input and one output which recognizes the sequence "0101" from an input stream. The circuit must recognize overlapping sequences, so the input x = 10101010 results in the output z = 00010101 (see Lab 6K in Table 6.2).

Available Hardware:

Digital lcomponent boxes - See Appendix G, SPDT momentary switch

Pre-lab preparation:

Part I - Sequence generation

Note that the circuit in Fig. 6.10 is used to simulate RUN button.
The initial test sequence is 10101111 and the analyzer detect a sequence "1111".

Part II - Sequence initialization control
Part III - Sequence detection
Part IV - Alternative design

Experimental Procedure:

During this experiment, be certain that you:

Post-lab analysis:

Generate a lab report following the sample report available in Appendix A. Mention any difficulties encountered during the lab. Describe any results that were unexpected and try to accoundt for the origin of these results(i.e. explain what happened). In ADDITION, answer the following questions:

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