PC/CP120 Digital Electronics Lab

Multiplexer Lab

Objective:

• To use Quartus II to draw and wire a circuit

Background:

For this lab consider a MUX with one output and four inputs, where one of the four inputs must be selected for output through 2 selection lines.

Suppose these are the signals going in on each of the inputs, from I₃ to I₀:


If the select inputs are set to 0, the output will be:


If the select inputs are set to 1, the output will be:


If the select inputs are set to 2, the output will be:


If the select inputs are set to 3, the output will be:


So if the select inputs cycle through all four possibilities, the output will be:

Background: Strobe, Gate, and Enable pins

Certain chips, like the multiplexer here, have "extra" inputs which allow more control over the outputs. With this multiplexer, there is a pin called strobe. This pin has to be connected correctly for the device to work as expected. Look at the device truth table to figure out whether this pin needs to be tied high or low.

Task:

You will use Altera Quartus II to draw your circuit diagram, and use the 74153M multiplexer from the others | maxplus2 library.


Quartus II may use different pin names than the datasheet (from ON Semiconductor) or the lab writeup. You should be able to figure out which pin maps to which based on the number and function of the various pins.
Simulate your circuit to confirm that the multiplexer works as expected.

Hint: Look at the inputs to the multiplexer and see if there are logical ways to group the inputs. You can make more than one input group in Quartus, and not all of the inputs need to be in a group.

Note that you can change how fast a group counts with the value in the "Count every" field.

Copy your directory from the E drive to the I drive.

Demonstrate the circuit to the lab demonstrator.

Delete everything from the E drive so your files don't get used by someone else later.