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- <title>Tutorial: Testing your circuit</title>
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- <p><b>Next:</b> <em><a href="../index.html">User's Guide</a></em></p>
- <h2>Step 4: Testing your circuit</h2>
- <p>Our final step is to test our circuit to ensure that it really does
- what we intended. Logisim is already simulating the circuit. Let's look
- again at where we were.
- <center><img src="../../../img-guide/tutorial-shot-all.png" width="498" height="302"></center>
- Note that the input pins both contain 0s; and so does the output pin.
- This already tells us that the circuit already computes a 0 when both
- inputs are 0.</p>
- <p>Now to try another combination of inputs. Select the poke tool
- (<img src="../../../icons/poke.gif" width="16" height="16">) and start poking the
- inputs by clicking on them. Each time you poke an input, its value will
- toggle. For example, we might first poke the bottom input.
- <center><img src="../../../img-guide/tutorial-shot-test.png" width="498" height="302"></center>
- When you change the input value, Logisim will show you what values
- travel down the wires by drawing them light green to indicate a 1 value
- or dark green (almost black) to indicate a 0 value. You can also see
- that the output value has changed to 1.</p>
- <p>So far, we have tested the first two rows of our truth table, and the
- outputs (0 and 1) match the desired outputs.
- <center><img src="../../../img-guide/tutorial-xor-table.png" width="163" height="131"></center>
- By poking the switches through different combinations, we can verify the
- other two rows. If they all match, then we're done: The circuit works!</p>
- <br><br>
- <p>To archive your completed work, you might want to save or print
- your circuit. The File menu allows this, and of course it also allows
- you to exit Logisim. But why quit now?</p>
- <p>Now that you are finished with tutorial, you can experiment with
- Logisim by building your own circuits. If you want to build circuits
- with more sophisticated features, then you should navigate through
- the rest of the help system to see what else you can do. Logisim is
- a powerful program, allowing you to build up and test huge circuits;
- this step-by-step process just scratches the surface.</p>
- <p><b>Next:</b> <em><a href="../index.html">User's Guide</a></em></p>
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