1 - Convert your ALU design in the previous lab into a 4-bit version and add the flags
in the Figure-1 below. The input and output variable names (coloured as red)
should be given as in the figure below.
B
A
A3
4
4
B3
ALUControlo
Sum3 ALUControl
4
4
Cout
+
Sum
4
4
4
4
11
01
00
10
ALUControl
2
4
result3
NZCV
14
Z
C
V
N
result
ALUFlags
2- - Create a testbench for the new ALU design, simulate the project and observe the
outputs.

Question

Accepted Answer

To address your question about converting the ALU design into a 4-bit version, adding flags, and creating a testbench for simulation, let's break it down step-by-step. ### Step 1: Convert ALU Design to 4-bit Version You need to modify your existing ALU design to handle 4-bit inputs and outputs. Here is a simplified version of a 4-bit ALU in Verilog: ```verilog module ALU ( input [3:0] A, B, input [1:0] ALUControl, output reg [3:0] Sum, output reg Cout, output reg [3:0] ALUFlags // N, Z, C, V ); always @(*) begin case (ALUControl) 2'b00: {Cout, Sum} = A + B; // Addition 2'b01: {Cout, Sum} = A - B; // Subtraction 2'b10: Sum = A & B; // AND 2'b11: Sum = A | B; // OR default: Sum = 4'b0000; endcase // Set flags ALUFlags[3] = Sum[3]; // N: Negative flag ALUFlags[2] = (Sum == 4'b0000); // Z: Zero flag ALUFlags[1] = Cout; // C: Carry-out flag ALUFlags[0] = (A[3] & B[3] & ~Sum[3]) | (~A[3] & ~B[3] & Sum[3]); // V: Overflow flag end endmodule ``` ### Step 2: Create a Testbench Next, you need to create a testbench to simulate the ALU and observe the outputs. Here is an example testbench in Verilog: ```verilog module ALU_tb; reg [3:0] A, B; reg [1:0] ALUControl; wire [3:0] Sum; wire Cout; wire [3:0] ALUFlags; ALU uut ( .A(A), .B(B), .ALUControl(ALUControl), .Sum(Sum), .Cout(Cout), .ALUFlags(ALUFlags) ); initial begin // Test case 1: Addition A = 4'b0011; B = 4'b0101; ALUControl = 2'b00; #10; // Test case 2: Subtraction A = 4'b0110; B = 4'b0010; ALUControl = 2'b01; #10; // Test case 3: AND A = 4'b1100; B = 4'b1010; ALUControl = 2'b10; #10; // Test case 4: OR A = 4'b1001; B = 4'b0110; ALUControl = 2'b11; #10; $stop; end endmodule ``` ### Step 3: Simulate and Observe Outputs Run the simulation using your preferred Verilog simulator (e.g., ModelSim, Vivado) and observe the outputs for each test case. ### Answer Choice ***D*** ### Key Concept ⚹4-bit ALU Design and Testbench⚹ ### Explanation ⚹The 4-bit ALU design includes handling 4-bit inputs and outputs, setting appropriate flags (N, Z, C, V), and the testbench is used to simulate and verify the ALU's functionality.⚹◊What is the significance of the ALUFlags in the context of digital logic circuits?⍭ Generate me a similar question◊

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