CS 2110 Timed Lab 2: Finite State Machines Solution

Please take the time to read the entire document before starting the assignment. It is your responsibility to follow the instructions and rules.
1 Timed Lab Rules - Please Read
1.1 General Rules
4. Resources you are allowed to use during the timed lab:
• Assignment files
• Previous homework and lab submissions
• Your mind
• Blank paper for scratch work (please ask for permission from your TAs if you want to take paper from your bag during the Timed Lab)
5. Resources you are NOT allowed to use:
• The Internet (except for submissions)
• Any resources that are not given in the assignment
• Textbook or notes on paper or saved on your computer
• Email/messaging
• Contact in any form with any other person besides TAs
6. Before you start, make sure to close every application on your computer. Banned resources, if found to be open during the Timed Lab period, will be considered a violation of the Timed Lab rules.
7. We reserve the right to monitor the classroom during the Timed Lab period using cameras, packetcapture software, and other means.
1.2 Submission Rules
1. Follow the guidelines under the Deliverables section.
2. You are also responsible for ensuring that what you turned in is what you meant to turn in. Aftersubmitting you should be sure to download your submission into a brand new folder and test if it works. No excuses if you submit the wrong files, what you turn in is what we grade. In addition, your assignment must be turned in via Gradescope. Under no circumstances whatsoever we will accept any email submission of an assignment. Note: if you were granted an extension you will still turn in the assignment over Gradescope.
3. Do not submit links to files. We will not grade assignments submitted this way as it is easy to changethe files after the submission period ends.
1.3 Is collaboration allowed?
Absolutely NOT. No collaboration is allowed for timed labs.
2 Overview
In this timed lab, you will implement a Binary Encoded State Machine in CircuitSim, and use k-maps to simplify the circuit logic. This Finite State Machine will take in one 1-bit input (G), and it will output two 1-bit outputs. The state machine is a Moore State Machine, where your output is based solely on the current state. Diagrams and detailed instructions are provided below.
3 Instructions
3.1 State Transition Diagram

Figure 1: Transition diagram.
3.2 Simplifying the Circuit
To help you to simplify the state machine logic, you are given a excel sheet you can use to construct the truth table and k-maps for the circuit; however, you are not going to submit the excel sheet for grading. Use the k-maps to find the fully reduced circuit for the state machine. Non-optimal circuits will not receive full credit.
3.3 Building the Circuit
Build your circuit using the tl2.sim file provided on CircuitSim. Complete the circuit so that the logic matches the diagram above. Functional circuits that are not fully reduced won’t receive full credit.
3.4 Restrictions
The input / output pins we have given you in the skeleton file must not be renamed. Do not add any additional input / output pins other than the ones we have given you. Do not rename the sub-circuit we have given you. If you have issues, check out the ”Common Errors” section below.
You are only allowed to use the following components in CircuitSim:
• Basic logic gates (NAND, NOR, AND, OR, NOT)
• Registers (for this assignment, exactly ONE).
• Wires, splitters/joiners, tunnels, constants, plexers
You are not allowed to use XOR/XNOR
4 Common Errors
Use the autograder’s output to determine where you have gone wrong. The names of the tests you fail should usually (but not always) point you in the right direction. Some common errors and their remedies:
1. Make sure you haven’t added extra any input / output pins to your circuit. It is common to confuseconstants with input pins, and probes with output pins.
2. Make sure the input / output pins are named the way they were when we gave you the file. If youchange the names of the pins (including from upper-case to lower-case, etc), the autograder will not be able to feed input in, and read your circuit’s output.
3. Make sure you haven’t changed the name of your sub-circuit. Keep it the same as what was given toyou.
5 Rubric
To run the autograder locally, navigate to the directly containing your timed lab and the tester and run the following command:
java -jar tl2-tester.jar
6 Deliverables
Please upload the following files to Gradescope:
1. tl2.sim
Download and test your submission to make sure you submitted the right files