Combinational Logic and Circuit Simulation in LabVIEW

Combinational Logic and Circuit
Simulation in LabVIEW
CSC/itec 3610 - Project (part 1)
Due midnight December 1 by email (vi file)
Introduction
Labview est un langage de programmation haut niveau permettant d’ écrire des
applications très évolués de façon simple à l’ aide d’ outils graphiques.
On bâtit le programme à l’ aide d’ icônes. Chaque programme Labview est composé
de deux parties: le panneau utilisateur et le diagramme. Le panneau indicateur est l’
interface usager. Si on écrit un programme pour un client, celui-ci ne verra que l’
interface usager. Il ne verra pas la partie programme (i.e. le diagramme). La partie
diagramme est la partie qui représente le programme tel quel. Dans un autre
environnement, on aurait toujours un interface usager , mais le programme serait écrit
en Visual Basic ou en C++ ou un autre langage classique. Ici il est écrit en Labview.
Pour le projet du cours, pourtant, vous n’ écrivez pas aucun programme.
Objective
The purpose of the first part of the project is to demonstate that different
representations of a Boolean circuit can have the same truth table using LabVIEW, a
graphical programming language for instrumentation (in our case computer
hardware) control and operation. You probbaly want to read again and try the
examples (in handouts in class) this week. The resulting vi file must be sent to me at
[email protected] by midnight December 1.
You will do the following:
1. Use LabView to build a circuit and determine its truth table.
2. Reduce the circuit using the rules of Boolean algebra, build the new circuit, and
prove its truth table is the same as in step 1.
3. Develop the POS equation from the truth table of step 1, build the circuit, and
prove its truth table is the same.
4. Develop the SOP equation from the truth table of step 1, build the circuit, and
prove its truth table is the same.
5. Replace all of the gates (both the AND and OR) from the circuit of the previous
step with NAND gates, and see how the truth table compares.
Multiple Input Gates in LabView
The multiple input gates in LabView are added to your diagram using the compound
arithmetic icon (the one in the box in the figure below).
When you first place the icon, it will appear as a two input addition
. To change
the number of inputs, use the mouse to grab one of the corners, and drag the icon
"larger" until you have enough inputs. To change the function (e.g., go from addition
to a logic AND) right-click on the icon, select "Change Mode", and click on the new
function you want the gate to perform. (See the figure below.)
You can also add inverters at the inputs or the output by right-clicking on the input or
output you want to alter and selecting "invert". This two-input AND gate has been
changed to a NAND gate by adding an inverter to the output.
Part 1: Build a Circuit and Determine Truth Table
For the first part of this lab, you will build the circuit represented below with the
Boolean equation.
Mine looked something like this:
Verify that my circuit is correct, then build and run the circuit using LabView.
Develop the truth table by switching the inputs on and off and marking the resulting
output. Call me over to verify the truth table before you move on to the next part.
Part 2: Simplify the Equation
You can reduce the equation by using Karnaugh techniques we have leanred. Once
you have reduced the equation, build the new circuit using LabView and verify that it
has the same truth table as Part 1.
Part 3: Proving the POS Circuit
Using the truth table that you developed from Part 1, create the POS equation.
(Product of Sums) Remember that this equation has a sum for every 0 in the truth
table. Once you have developed the POS equation, build the new circuit using
LabView and verify that it has the same truth table as Part 1.
Part 4: Proving the SOP Circuit
Using the truth table that you developed from Part 1, create the SOP equation. (Sum
of Products) Remember that this equation has a product for every 1 in the truth table.
Once you have developed the SOP equation, build the new circuit using LabView
and verify that it has the same truth table as Part 1.
Part 5: Implementing the SOP Circuit With NAND
Logic
Replace ALL of the gates except the inverters with NAND gates. (this means both the
ANDs and the OR.) This is easiest to accomplish by right-clicking on each AND and
OR gate and selecting replace. From the functions window that pops up, select the
NAND gate. Once you have created this new circuit, see how its truth table compares
with that of Part 1.
Part 6: Send me the resulting "vi" file, together with
an one-page-only description, by midnight Dec 1. Bon
travail.