Subsections

• 2.1 Basic Behavior of HCMOS Logic Family
• 2.2 Half Adder

2 Lab

2.1 Basic Behavior of HCMOS Logic Family

1. Use the datasheet to connect a 7404 IC.
2. Verify the operation of the inverter by connecting the input to $V_{cc}$ and $GND$ .
3. Use a variable 10k$\Omega$ pot to vary the input to the inverter. When does the output change.
   

4. Build the circuit shown in Figure 1 using 10 inverters in series. Set the output of the function generator that you build in Lab 0 to 15 kHz and connect it to the input of your circuit. Can you observe the output of the your circuit by using a voltmeter or a logic probe.
5. Connect the output of your circuit to the logic analyzer and record your observations. (Use the information provided in 3.1 to run the logic analyzer).
6. Does the output match what you expected? Why or why not?

   Figure 1:

   

7. What is the propagation delay of an inverter gate?

2.2 Half Adder

1. Write the truth table for the circuit shown below.

   Figure 2: Half Adder

   

2. Connect ICs from the 7400 family to implement the circuit shown above.
3. Verify the operation of the circuit by connecting the inputs to different combinations of $V_{cc}$ and $GND$ .
4. In terms of binary arithmetic, what do the $S$ and $C$ outputs represent?.