Lab #06: Adder Design Tradeoffs

ECE 380: Lab #06: Adder Design Tradeoffs
In this lab, you will use the Quartus prime software package to design and simulate one 4-
bit subtractor and one 4-bit CLA adder. The requirements for this lab consist of completing
Quartus Prime designs, downloading designs to the Atlera DE1 board, printing circuit
diagrams, VHDL files, simulation results, and the laboratory report.
1. Implement Design A of the prelab. Use the test vectors given in the table below to
verify the correctness of the circuit in functional simulation.
Suggested pin assignment:
Cout LEDR[9]
Over LEDR[8]
S[3] LEDR[3]
S[2] LEDR[2]
S[1] LEDR[1]
S[0] LEDR[0]
X[3] SW[9]
X[2] SW[8]
X[1] SW[7]
X[0] SW[6]
Y[3] SW[5]
Y[2] SW[4]
Y[1] SW[3]
Y[0] SW[2]
2. Download and test Design B to the DE1 board, Cyclone® V 5CSEMA5F31C6
chip. Use the same test vectors as in 3 and compare the results you get from the
board and the simulator.
Suggested pin assignment:
Cout LEDR[9]
S[3] LEDR[3]
S[2] LEDR[2]
S[1] LEDR[1]
S[0] LEDR[0]
A[3] SW[9]
A[2] SW[8]
A[1] SW[7]
A[0] SW[6]
B[3] SW[5]
B[2] SW[4]
B[1] SW[3]
B[0] SW[2]
3. (Bonus part) Download and test Design C to the DE1 board, Cyclone® V
5CSEMA5F31C6 chip. Use the same test vectors as in 3 and compare the results
you get from the board and the simulator.
(Bonus part): Use HEX0 [6..0] to display the sum, A.
Use HEX1 [6..0] to display the sum, B.
Use HEX2 [6..0] to display the sum, S.
Use LEDR[8] for Cout.
User LEDR[9] for overflow.
4. Have the TA verify your results
Design A
Input X 0x5 0xB 0xB 0x7 0x7 0x9 0xB 0x5 0xC
Input Y 0x2 0x2 0xE 0x2 0xE 0xE 0x2 0x2 0x5
EXPECTED S
EXPECTED Cout
EXPECTED Over
SIMULATED S
SIMULATED Cout
SIMULATED Over
Design B
EXPECTED SIMULATED DE1 Board
A(hex) B(hex) S Cout S Cout S Cout
8 E
E 5
C 3
3 2
8 F
Homework #06 (100 points):
Q1(30 pts). Use full adders to implement a multiplier from Z = X * Y, where X is 3-bit
unsigned number and Y is a 3-bit unsigned number, and Z is a 6-bit unsigned number. Draw
the block diagram of the circuit and explain your design.
You can use simple logic functions as the inputs to the full adders.
Q2 (30 pts). Carry Look-Ahead (CLA) adder to add two 5-bit binary numbers
(X=𝑥𝑥4𝑥𝑥3𝑥𝑥2𝑥𝑥1𝑥𝑥0, Y= 𝑦𝑦4𝑦𝑦3𝑦𝑦2𝑦𝑦1𝑦𝑦0).
Please derive the logic expression of the carryouts, 𝑐𝑐1, 𝑐𝑐2, 𝑐𝑐3, 𝑐𝑐4, 𝑐𝑐5
Q3 (40 pts): Write down the truth table and the SOP logic function for a 2-out-of-4
detector.
Definition of 2-out-of-4 detector: for a 4-input logic, if and only if 2 of inputs are ‘1’, the
output will be true.