This can be done in Multisim or Multisim Live. Please answer fully and legibly.

AND Gate and OR Gate

Objective

Test the logic for an AND gate and OR gate, and get familiar with their Truth tables.

Materials needed

One 74LS08 quad 2-input AND gates

One 74LS32 quad 2-input OR gates

Jumpers (wires)

Figure 1 AND gate, OR gate ICs, and their standard symbols

Summary of Theory

Gate circuits are the building blocks of all digital circuits. The AND, OR, and inverter gates are the three fundamental gates. In this experiment, you will test two of these types. You will see the output of an AND gate is HIGH only if all inputs are HIGH. You will also observe that the output for all possible input combinations. The measurements are repeated for the OR gate.

You will see the output of an OR gate is LOW only when all inputs are LOW. Logic switches control the inputs, so you will connect a switch on the proto board to select a HIGH or LOW. HIGH and LOW designations are used when refer to electrical voltages. You will use positive logic in the procedure, meaning a HIGH will corresponds to a Boolean logic 1 and a LOW will corresponds to a Boolean logic 0.

Procedure, the AND gate

1. Connect 74LS08 AND gate as shown and connect wire from two switches to the two input pins of the gate. These are the two inputs to the AND gate. The switches are labeled for reference as S1 and S2. Connect the output to the LED indicator.
2. Set both switches to LOW (Logic 0). Observe the LED output indicator. You should observe Logic 0 output (LED indicator turns on), record this logic on the first row of the table as 0 (under the column x). Measure the output of the AND gate with the voltage meter or voltage probe, and record the measured values on the first row of the table under Measured output voltage.
3. Set the S1 and S2 switches to each of the remaining combinations of inputs listed in the table. Record the output logic, and voltages. Remember when LED is off, it is Logic HIGH or 1, and when LED is on it is Logic LOW or 0. Complete the table.

Figure 2: AND gate circuit

Table 1: AND Gate Truth table

Inputs		output	Measured output voltage
S1	S2	X
0	0
0	1
1	0
1	1

The OR Gate

4. Turn off the power and carefully replace the 74LS08 IC with the 74LS32, which is a quad 2-input OR gate. The pinout is identical to 74LS08. Replace the jumper from switch S2 to pin 2. Set switches S1 and S2 to logic 0. Read the output logic on pin 3 using LED probe. Enter the logic observed in the first row of the table below.

5. With your DMM set to DC Voltage, measure the output from the OR gate and record it in the first row of the table.

6. Set the switches S1 and S2 to each of the combinations of inputs listed in the table. Check the setting of the switches, and record the output logic using the LED indicator, and voltage probe or meter. Complete the table.

Figure 3 OR gate circuit

Table 2 OR Gate Truth table

Inputs		output	Measured output voltage
S1	S2	X
0	0
0	1
1	0
1	1

1. Assume you need a gate that has a LOW output if any input is LOW. What kind of gate do you need to select?

2. Assume you need a gate that has a HIGH output if any input is HIGH. What kind of the gate do you need to select?