Computer Science 220
Assembly Language & Computer Architecture

Fall 2011, Siena College

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In this first hands-on digital logic lab, our objective is to familiarize you with the workings of the digital lab by constructing a few simple TTL circuits. You will also construct some circuits in Logisim.

Given equipment limitations, most if not all of you will need to work in groups of two.

The in-lab portion of this assignment is available only as a handout, not the online version. Here is an electronic version of the Integrated Circuit Handouts you received in lab.

Logisim Problems

You may work alone or with a partner on these problems.

1. Develop a Logisim circuit that implements the 5-input AND gate using only 2-input AND gates that you wired in lab. Use Logisim "Pin" components for the inputs and output. Include your name(s) as a label in each of your circuits.
2. Develop a Logisim circuits that implements the full adder using only NAND gates that you drew in lab. Use Logisim "Pin" components for the inputs and outputs. Include your name(s) as a label in each of your circuits.
3. Starting with the circuits in the adders.circ class example circuit file, use Logisim to construct an efficient 8-bit ripple carry adder using three 4-bit ripple carry adders connected in the way we discussed in class to compute the result in about half of the time of the sraightforward 8-bit ripple carry adder. Use Logisim "Pin" components for the inputs and outputs. Take advangage of the "4bitrcadder2" circuits as building blocks, and keep inputs and internal wires grouped where possible to keep your circuit from becoming overly complex. Include your name(s) as a label in each of your circuits.

Grading and Evalulation

This lab is graded out of 35 points.

By the start of your next lab session, submit the completed lab problem sheet (hard copy) and your Logisim circuits as attachments by email to jteresco AT siena.edu.