Description
● Create a Lab2 folder (note the capitalization convention, include no extra
characters in the directory name) that contains the following files:
○ Lab2.lgi in the Lab2 folder
○ README.txt
● Commit and Push your repository
● Tag the commit that you would like to be graded
○ The tag must be in the form Lab2_submission_# (note the capitalization
convention)
Lab Objective
In this lab you will design and simulate a guessing game that compares a user input
to a random number. If the user input matches the random number, the score is
incremented by 2; if the user guesses low, by 1, and if the user guesses high, by -1.
Description
A random number will be generated and compared against a keypad entry. Seven-segment
displays will be used to display the user answer (keypad entry), the correct answer
(random number), and the score.
Use two’s complement to keep track of a negative score. Numbers shown must be human
readable, i.e. if the value is negative, the score must be shown with a negative
sign. (Hint: If the number is negative, display the additive inverse and a negative
sign.)
Top Level
Here is a top-level block diagram of the game. Note that clouds indicate
combinational logic.
Lab 2 Page 1 of 6 Fall 2018
Figure 1: Top Level Diagram
Lab 2 Page 2 of 6 Fall 2018
Note
For the register, use D flip-flops, and make sure they are edge triggered with a
clear line. You may NOT use the counter, mux or ALU objects provided in MML.
USE DON’T USE
Figure 2: MML Palette
For your convenience, here is a tabular description of how flip-flop with clear line
works. You may also find practice_flipflow.lgi handy for understanding how flip-flops
set and reset.
Extra Credit
You may have noticed, with the current implementation, you can cheat by simply
pressing the keypad after the random number is generated and displayed.
1. Add functionality to prevent users from cheating in this fashion.
2. Make the “Always Show Correct Answer” switch work. Make it so when the switch
is off, the seven segment display for “correct answer” will display “0.” (zero
with a decimal point). If the switch is on, it will show the random number (no
decimal point). Hint: think about muxes.
If you choose the extra credit route, add a comment on the first page of the template
indicating you have chosen the extra credit option.
Template
The components on the first sheet of your schematic file should match the template.
You are permitted to change only the text – your name, CruzID, and the sender and
receiver names if you’d like. Additional wires and logic circuits shall be drawn on
subsequent pages. If you are not choosing the extra credit option, remove the switch
labeled ‘cheat’ and the sender associated with it. You may add as many pages as
necessary.
Lab 2 Page 3 of 6 Fall 2018
Figure 3: Lab 2 Template
An example of how to hook up the D flip-flop is shown on page 2 of the template. This
circuit should be deleted in the version of the lab that you turn in.
Lab 2 Page 4 of 6 Fall 2018
Figure 4: Flip-flop Usage Example
Comments
Each page should be labeled with your last name, first name, and CruzID (the name
used in your UCSC email address). Label each circuit with a description of the
functionality and the part of the lab that they are for.
Visual Structure
Presentation of information is an important part of deliverables. Clean documentation
is easy to comprehend and looks professional. Your circuits should be structured in
an organized method that is easy to read and interpret. Using the “Snap to Grid”
setting under the View menu makes it easy to line up components. Do not have crossing
wires.
README.txt
This file should be a plain text document and contain your last name, first name, and
CruzID. Use the template shown below (also on canvas). Put effort into your answers.
What were the learning objectives of this lab?
Write the answer here.
Did you encounter any issues? Were there parts of this lab you found enjoyable?
Write the answer here.
How would you redesign this lab to make it better?
Write the answer here.
Lab 2 Page 5 of 6 Fall 2018
Missing Wire Best Practices
MML has a known bug which causes some wires to disappear after reopening the file. To
reduce the likelihood of this occurring, DO NOT use the “Node” tool (it’s a tiny
black dot located at the top-right of the tool palette). This tool is particularly
vulnerable to the bug.
If this bug occurs, the grader will attempt to repair the missing wire in your file.
This is only possible if your circuit is very readable. Make sure that wires do not
cross whenever possible. Wire paths should be short and direct. Use receivers very
liberally.
Lab 2 Page 6 of 6 Fall 2018
