CSCI 232 Lab 3

Fun with Arithmetic

Date Due: 15 February 2012

This assignment will give you more practice with the 7400 family of combinational circuits. You will be building more complex circuits, and can use some of the more complex gates in the series, as needed.

Note: Before you build any circuit using the CADET, you are to first simulate your design using LogicWorks and verify that it performs the desired operations. You are to print out your LogicWorks schematic including pin numbers and chip ID’s. Be sure to include your name, the course, the date, and the lab number in a box on your schematic.

Each person is to do their own circuit design for this lab. You should demonstrate to me that your design works in LogicWorks before moving on to actually implementing any circuit. Once you start to actually implement the design, you may work in teams of two, choosing one design to implement. Do not turn the power on to the CADET until you have double checked your wiring! After you have tested and implemented each circuit, you are to demonstrate it to me for grading. At the end of the lab, you should return all wires and IC’s to the appropriate storage places, and put the CADETs back on the shelves. Cleaning the lab up after yourselves is part of the lab!!

For this lab you are to build a circuit that does BCD arithmetic. Your circuit should take 8 inputs (2 sets of 4 bits) and output 4 bits plus a carry. To make your life easier you may use a 7483 circuit in your design. In BCD arithmetic, you use 4 bits to represent the digits 0 through 9. If the sum exceeds 9, you generate a carry and subtract 10 from the sum to get the correct digit. (In other words you do the familiar base 10 arithmetic that we all know and love…it’s just that you need 4 bits to represent each digit since they can range from 0-9. The bit patterns representing 10-15 aren’t used.)