HW 6 - Digital Schematics

The intent of this HW is to teach you how to draw and simulate digital logic schematics.

Download Digital

1. Download Digital from GitHub.

2. Unzip Digital and copy the entire unzipped it to someplace convenient.

3. You don’t actually need to install Digital; you can just run the Digital.exe by double clicking on it.

4. You may be prompted to install Java Runtime.

   • On a MissionNet computer you can install from the Self Service Client.

   • On another computer you can follow the link or search it on the web.

Half adder, again

Let’s revisit the half adder!

1. Run Digital

2. It should open an empty file, but if it doesn’t create a new file.

3. Now, create a half adder!

   • Components > IO > Input

   • Components > IO > Output

   • Components > Logic > AND

   • Components > LOGIC > XOR

4. Connect everything with wires. For example, click the red dot on the right side of one input, then click the blue dot on the left side of a logic gate. While dragging a new wire you can click on the grid to make it turn 90 degrees. You can also click on an existing wire to start a wire from that point. A dot (solder joint) on two wires shows that they are connected at that dot!

5. Right click on each of the inputs and outputs and give them a Label (i_A, i_B, o_S, and o_Cout).

6. File > Save As and name your file halfAdder.dig

You can now simulate the circuit to see if it works as expected.

Simulation > Start of Simulation or the play button in the center tool bar.

Then click inputs to see if outputs behave as expected!

Submission

Upload halfAdder.dig to the gradescope assignment.

Important

You must use the exact label names that we specified above, otherwise the autograder will not work.

This is actually very realistic; engineers have to design interfaces that work with external systems according to published standards!