Truth Table Generator

The Truth Table Generator allows you to perform combinational network analysis exercises by manually filling in the corresponding truth table and verifying the solution. It also allows you to automatically generate the table, if needed.

The following example proposes a combinational network with three inputs (A, B, C) and two outputs (SUM, CARRY). We choose to generate the Truth Table of the output SUM. To do this, a command [Truth Table] is available, at design time, in the context menu of the One-bit Output component (by clicking on the figure below, you can replicate this operation directly in the Deed-DcS).

The command opens a dialog window displaying a truth table to complete. It displays all input combinations of A, B and C, leaving the output column SUM unfilled (highlighted by the green arrow, see below).

The dialog window has two modes, selectable via the toolbar at the top (orange arrow). The default is 'By User', which allows the student to manually enter values in the output column. On the right, you can see the two-state Check button (yellow arrow). It is currently inactive, so the user does not currently receive any feedback on the correctness of the answers (we will activate it later).

In the output column, cells not yet defined by the user display dots '...'. When clicked, a small menu appears next to them with the options '0' and '1', as shown below, so the user can then choose the value to enter. Alternatively, we can also press the '0' or '1' keys on the keyboard (the new value will be inserted into the selected row). Note that the inputs in the schematic take on the value corresponding to the selected row in the table. Instead, the output in the schematic does not show the value that would be generated, so as not to suggest the answer to the student.

Let's now assume we activate the Check mode using the button we saw earlier. We can do this at any time; in this example, let's assume we do it before we've finished filling in the table (see below).

As you can see in the figure, wrong answers are highlighted with a pink background. On the right side, above the Check button, a summary appears. In this example, there are 2 incorrect answers and 3 remaining, out of a total of 8 rows.

If we don't want to practice, but want to get the truth table right away, simply activate the 'Auto' mode on the top toolbar. The table will be completely filled (not editable), as shown in the screenshot below. In this mode, selecting a row in the table will update the values shown by the input and output component in the schematic.

The yellow arrow, instead, indicates a button we can use to save the entire table to a text file in CSV (Comma Separated Values) format. Once you click the button, a panel appears with the file encoding settings, as shown below (left). On the right, the generated CSV file, as it appears in Excel (MS).

Just below the 'Save CSV' button we saw earlier, we find the button 'Equation' that allows us to view the Boolean equation of the output versus the inputs, which the system has previously derived by analyzing the network. By pressing it, in this example we get the following (for each output):

Lastly, the users can rearrange the order of the input columns as and when they wants. Clicking on the name of an input at the top of the table will bring up a menu with commands for moving that column to the left or right (see below).

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