Due date: See Canvas

0. Preparation

• Open a SSH application on your PC and connect to lab0z (if you don't know what to do, read the instructions on Canvas in the tab "Software and information used in CS355...")

  Execute these command (copy and paste) in the SSH window to make a assignment sub-directory hw1 and copy the prepared file for this assignment:

  mkdir ~/cs355/hw1 cp /home/cs355001/Handouts/hw1/* ~/cs355/hw1

  Verify the result by executing this command in the SSH window:

  ls ~/cs355/hw1

  You should see this file name:

  hw1.h - This file contains the circuit that you must make for assignment 1

1. Assignment Description

This assignment reinforces the material in Chapter 1 of the CS355 Syllabus.
Read Chapter 1 of the lecture notes online at this link if you have problem designing the circuits: click here
Pay special attention to the notes on "Combinatorial circuit design": click here and the lecture slides: click here

In this assignment, you will design and implement a circuit with 5 inputs a, b, c, d and e and 3 outputs x, y and z that counts the number of one's in the input.

For example, if the input signals are a = 1, b = 0, c = 1, d = 1 and e = 1, then the output signals xyz = 100 representing the number 4 in the binary system.

If the input signals are a = 1, b = 1, c = 1, d = 1 and e = 1, the output signals should also be xyz = 101 (= 5).

And if the input signals are a = 1, b = 1, c = 0, d = 0 and e = 1, then the output signals should be xyz = 011, representing the number 3 in the binary system, and so on.

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Here is another example and shows what the ciruit should do when the input signals are a = 1, b = 0, c = 0, d = 1 and e = 1:




Note: if you need a refresher on binary numbers, the CS255 online notes on this subject is here: click here

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Write a EDiSim "program" that implement the above circuit.

Put the switches on the left (you will need 5 switches), the probes on the right (you need 3 probes) and the digital circuit between the switches and the probes.

Use the following coordinates for the components:

The Switches and NOT-gates havealready been added in the first column (in the skeletal file that you have copied): Switch aa A '0' ZERO; Not aa A NOTA; Switch ba B '1' ZERO; Not ba B NOTB; Switch ca C '2' ZERO; Not ca C NOTC; Switch da D '3' ZERO; Not da D NOTD; Switch ea E '4' ZERO; Not ea E NOTE; The signal names for the switches are: A, B, C, D, E The NOT signals of each switch has been constructed already and the signal names of the NOT-gate for the corresponding switches are: NOTA, NOTB, NOTC, NOTD, NOTE, respectively. You need to complete the rest of the circuit. Put all the AND-gates that computes the 1st bit of the binary number at coordinate ed Put all the AND-gates that computes the 2nd bit of the binary number at coordinate cd Put all the AND-gates that computes the 3rd bit of the binary number at coordinate ad Put the OR-gate that connect the values from the AND-gates for the 1st bit of the binary number at coordinate ee Put the OR-gate that connect the values from the AND-gates for the 2nd bit of the binary number at coordinate ce Put the OR-gate that connect the values from the AND-gates for the 3rd bit of the binary number at coordinate ae Finally, put the probe for the 1st bit of the binary number at coordinate ef Put the probe for the 2nd bit of the binary number at coordinate cf Put the probe for the 3rd bit of the binary number at coordinate af

This is what your circuit should look like:

Note:

You can be creative and find more efficient solutions on your own and implement it.

2. How to do EDiSim assignments

To do EDiSim assignment, you must be set up your PATH environment variable. You can accomplish this by running this command inside a SSH window:

Execute this command: /home/cs355001/bin/add.path Then: (1) Logout (exit your SSH session) and (2) Use a new SSH window to log back in to a CS lab machine (3) Verify the process by running this command in the SSH window after you log in: type cs355sim It should return: cs355sim is a tracked alias for /home/cs355001/bin/cs355sim

You only need to do this once

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• Complete assignment 1 by editing your hw1.h assignment file using these commands:

  (Do these steps after you have SSH/remote login to a lab machine) Execute these command in the SSH session: cd ~/cs355/hw1 (this command will change working directory to "hw1") (You can omit this step if you are already in ~/cs355/hw1) nano hw1.h (this command starts the nano editor on file "hw1.h") (I recommend nano because it's easy to use) (If you are familiar with Linux and have used a diffeent editor, you can use your favorite editor)

  Use nano to write the EDiSim circuit program that implement the circuit describe in assignment 1. When you're done, save your file and run it with the command described below.

  I have a brief nano tutorial here to help you learn to use the nano editor: click here

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• To make grading uniform, the skeletal file hw1.h that you can copied in the preparation step uses the following key assignments:

  Top switch: uses the key 0 to toggle           Second switch: uses the key 1 to toggle Third switch: uses the key 2 to toggle Fourth switch: uses the key 3 to toggle Bottom switch: uses the key 4 to toggle

  DO NOT make any changes to this ! (Or else, we will have a hard time grading your circuit).

  To run your circuit use this command (inside the ssh session):

  cd ~/cs355/hw1 (this command will change working directory to "hw1") (You only need to execute this command once per SSH session) cs355sim hw1.h (this command runs the circuit simulation) // NOTE: If you get the error message: cs355sim: not found // Use: /home/cs355001/bin/cs355sim hw1.h (Your PATH environment variable is wrong) Tip on how to work on the assignment: Use 2 SSH windows Use 1 window to edit your assignment file hw1.h (with nano) Run the cs355sim command in the other window

  A window will pop up showing the circuit simulation. You can interact with the circuit simulation by toggling the keys '0', '1', '2', '3' and '4' to change the switches value (0 or 1).

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  Verify correct circuit behavior

  • I have made available compiled programs of the correct solutions in the directory /home/cs355001/Solutions

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  • To see how the assignment 1 circuit should behave, use this command (executed inside the ssh session):

    /home/cs355001/Solutions/hw1-sol

3. Turn in

You must turn in your circuit file hw1.h using the following commands (in a ssh window):

cd ~/cs355/hw1 (this command will change working directory to "hw1") /home/cs355001/turnin hw1.h hw1 (this command turns in your assignment file)

4. Extension requests

• Each assignment must be turned in before the specified dead line (see class webpage for the deadline

• You can request upto 3 extensions in the semester without any penalties without any questions asked

  (A 4th extension request will be automatically denied --- personal emergencies and illiness with documentation will receive a "free" extension)

• To request an extension for this assignment, us the following command:

  /home/cs355001/req-ext hw1

5. Handling Errors in Logic-Sim

I will be compiling a list of commonly asked questions/answers on the assignments.

The list of commonly asked questions/answers is accessible through the following hyperlink: click here

Students will be graded partially on the basis of their programming assignments. These programming assignments are to be treated as examinations, and are expected to be your individual work. While discussions with other students in the course may be permitted or encouraged by your instructor, you should write your program yourself. The mathlab representatives are available to explain error messages, discuss briefly technical details with which you may not be familiar, and give short suggestions as to how you might detect logic errors. The reps should not, however be asked to write part or all of your program. Your instructor (and any teaching assistants assigned to the course) will be glad to help you to the extent that he or she feels reasonable.

Submissions based on other students solutions in prior offerings of the course specifically violate these guidelines, as do submissions prepared with the help of an outside "tutor".

You should take precautions to protect the confidentiality of your work: preserve the secrecy of your password, do not make files or directories sharable, pick up your printouts promptly and dispose of printouts where they will not tempt other students. All work should be done either in the class directory of your ITD account (preferred) or in your "priv" directory (only if you do not have a class directory).

All submissions should include a comment statement near the top of the program of the form:

THIS CODE IS MY OWN WORK, IT WAS WRITTEN WITHOUT CONSULTING A TUTOR OR CODE WRITTEN BY OTHER STUDENTS - your name

Cases of apparent plagiarism or collusion will be referred to the Honor Council.