Due

Objectives

• to understand the operation of combinational circuits

Reading

Assignment

Use the applet shown above to

1. Build the circuit in Question 1 on p. 26. Give the complete I/O table for the circuit.
2. Build a circuit equivalent to the one in Question 5a by replacing the NOR gates with an OR gate whose output is connected to a NOT gate. Give the complete I/O table and note which Boolean function it is equivalent to.
3. Build a circuit equivalent to the one in Question 5b by replacing the NAND gates with an AND gate whose output is connected to a NOT gate. Give the complete I/O table and note which Boolean function it is equivalent to.
4. Build a circuit with eight inputs. Put the first two inputs through an XOR gate, the next two through another XOR gate, and so on. Take the first two XOR gates and put their outputs through another XOR gate. Continue until there is only one output. Do not give the complete I/O table for this circuit (how big would the complete table be?), but describe in English what this circuit does.
5. Build a circuit with three inputs where the output is on (1) exactly when at least two of the inputs are on. You can create this circuit with three AND gates and and two OR gates: one AND gate determines if the first two inputs are both on, the second determines if the last two are both on, and the third determines if the first and the last are both on. The output of the complete circuit should be on if one of the first two AND gates' output is on or if the last AND gate's output is on.

Submissions

Submit, on paper, drawings of your circuits, I/O tables for your circuits, and the answers to the above questions.