The Truth Modules

The Truth 3 Faceplate

Customizable truth tables with 2, 3, or 4 inputs.

Truth 3 is shown, and described below. Truth 2 and Truth 4 offer similar functionality, with 2 and 4 inputs, respectively.



The Truth Table




Usage Notes

Level-Triggered vs Edge-Triggered

Level-Sensitive. The HIGH and LOW conditions make the table sensitive to the level of the C/GATE input. This makes the C/GATE input useful as an enable signal, such as for a D Latch.

Edge-Triggered. The RISE, FALL, and EDGE conditions make the table edge-triggered. This makes the C/GATE input useful as a clock signal, allowing changes only at precise moments, when the clock rises or falls.

Note that RISE, FALL, and EDGE are single sample events.

Caution: Selecting the ¬Q Result

Because the ¬Q result causes the table’s output to toggle, it tends to be useful only for edge-triggered rows. That is, only when:

To see why, consider: If the row is level-triggered, it might be selected for many samples in a row. On each sample, the output toggles, producing a square wave at the Nyquist frequency. That’s probably not what you want.