CSE/EEE 120
Lab 2 Answer Sheet
Multiplexers, Decoders and the Arithmetic and Logic Unit (ALU)
Task 2-1: Build and Test a 1-Bit 2:1 Multiplexer
Include a picture of your Digital circuit here:
Please comment on the single biggest issue you were facing when designing the circuit.
This was a relatively easy, so I didn’t face any issues.
Task 2-2: Build a 4-Bit 2:1 Multiplexer
Include a picture of your Digital circuit here:
Please comment on the single biggest issue you were facing when designing the circuit.
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I didn’t face any issues.
Include a picture of your simulation (timing diagram) here:
Which tests did you perform and why? Use the following table to describe your test sequence. You need
to make sure to perform a sufÏcient number of tests to check the circuit for eventual faults.
Test Stimulus Test Motivation Pass/Fail
2_0_2_1 Y should equal to a when sel=0 Pass
1_1_2_1 Y should equal to a when sel=1 Pass
B_0_B_5 Testing if sel works with
different inputs(when it is 0)
Pass
6_1_5_6 Testing if sel works with
different inputs (when it is 1)
Pass
C_0_C_C Testing when a and b are the
same, and sel is 0
Pass
C_1_C_C Testing when a and b are the
same, and sel is 1
Pass
0_0_0_0 Testing when everything is 0 Pass
Please comment on the single biggest issue you were facing when simulating the circuit.
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I didn’t face any issues.
Task 2-3: Add 7-Segment Displays to Your Circuit
Include a picture of your Digital 7-Segment Display here:
Please comment on the single biggest issue you were facing when adding the displays.
I didn’t face any issues.
Task 2-4: Build the NOT/NEG Circuit
Include a picture of your Digital circuit here:
Please comment on the single biggest issue you were facing when designing the circuit.
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I didn’t face any issues. Wasn’t too hard.
Task 2-5: Build the AND/ADD Circuit
Include a picture of your Digital circuit here:
Please comment on the single biggest issue you were facing when designing the circuit.
Trouble with connecting the wires.
Task 2-6: Build and Test the ALU Circuit
Include a picture of your Digital circuit here:
Please comment on the single biggest issue you were facing when designing the circuit.
I didn’t face any issues.
Please complete the ALU function definition table shown below:
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arith invert pass Function
0 0 0 AND
0 0 1 Pass-through (A) -
Logical Context, always
passes A
0 1 0 Invert A one’s
complement, OR
0 1 1 Pass-through (A) -
Logical Inverted Context,
gives A one’s
complement
1 0 0 Arithmetic Sum, A+B
1 0 1 Pass-through (A)
1 1 0 A invert two’s
complement, and it
subtracts the numbers
(A and B)
1 1 1 Pass-through (A) -
Arithmetic Inverted
Context, gives the value
of A two’s complement
Include all pictures of simulations (timing diagrams) for each function here. With each picture, paste the
test_vals from your stimulus file for that test.
ADD (test_vals):
test_vals[0] = 18'h0_3_4_1_2;
test_vals[1] = 18'h2_9_4_5_4;
test_vals[2] = 18'h0_7_4_3_4;
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Passthrough_A_Logical:
test_vals[0] = 18'h1_5_1_5_3;
test_vals[1] = 36'h0_A_1_A_3;
test_vals[2] = 18'h1_9_1_9_7;
AND:
test_vals[0] = 18'h1_1_0_3_5;
test_vals[1] = 18'h1_4_0_6_4;
test_vals[2] = 18'h1_1_0_9_7;
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Ones Complement of A:
test_vals[0] = 36'h0_5_B_A_3;
test_vals[1] = 36'h0_1_B_E_4;
OR:
test_vals[0] = 18'h1_2_2_5_6;
test_vals[1] = 18'h0_3_2_4_3;
Passes through A:
test_vals[0] = 18'h1_5_5_5_3;
test_vals[1] = 36'h0_A_5_A_3;
test_vals[2] = 18'h1_9_5_9_7;
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Subtract:
test_vals[0] = 36'h1_0_6_A_A;
test_vals[1] = 18'h1_2_6_3_5;
test_vals[2] = 36'h0_E_6_7_5;
Twos Complement:
test_vals[0] = 36'h1_6_F_A_5;
test_vals[1] = 18'h1_7_F_9_7;
test_vals[2] = 36'h0_D_F_3_2;
Did the circuit behave as expected? If no, what was wrong?
YES
Please comment on the single biggest issue you were facing when simulating the circuit.
The biggest issue I faced was that I had trouble picking the hex number.
Task 2-7: Create a video and submit your report
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Record a short video showing your schematics in Digital and your waveforms in GTKWave. Be sure to
show yourself in the video and show your screen. Explain how your circuit works – you need to convince
the grader you did the lab and understand it! Copy and paste the link to your video below. Make sure
the link is working and pointing to the correct video. Remember to include the password if required.
Do NOT upload your video to Canvas. It is recommended that you use Zoom to record to the cloud,
pasting the link and password below. If your circuit is not working as expected, explain in the video how
it is not working and why you think it is not working.
Video Link: https://asu.zoom.us/rec/share/1sJUr3jkN-
DVqxH8sj0YylvF3B4bM4tjYEjhngzuVktw5nHFb2kMSdx5CqFGZQ.PCwI0kBNbpt1Ngqb
Password: $z9wBq1^
At the beginning of your recording, say your name and the lab name. Be brief in
your recording. Submit the completed template to Canvas.
Make sure all your files are in the Lab2 directory. Create a zip file of the Lab2
directory. Remember to turn in the zip file and your completed template on
Canvas!
Do not include the video in the zip file! This makes the file very large and you
run the risk of the zip file not uploading or taking so long to upload that your
submission will be late. Remember that the submission is dated at the time the
upload completes, not when it starts!
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LAB 2: L R G SAB EPORT RADE HEET
Name
NOTE: You submit the zip file in order to show your work.
If the zip file is not submitted there is a 5 point deduction!
Instructor Assessment
Grading Criteria Max Points Points Lost
Description of Assigned Tasks, Work Performed & Outcomes Met
Task 2-1: Build and Test a 1-bit 2:1 Multiplexer 5
Task 2-2: Build a 4-Bit 2:1 Multiplexer 5
Task 2-3: Add 7-Segment Displays to Your Circuit 5
Task 2-4: Build the NOT/NEG Circuit 5
Task 2-5: Build the AND/ADD Circuit 10
Task 2-6: Build and Test the ALU Circuit 10
Task 2-7: Create a video and submit your report. 10
Points Lost
Lab Score (50 points total) Late Lab
Lab Score
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