VeriLog

1-bit full adder.

Gate-Level Modeling

module full_adder_gate_level (input A, input B, input Cin, output Sum, output Cout);
    wire w1, w2, w3, w4, w5;
    xor gate1 (w1, A, B);
    xor gate2 (Sum, w1, Cin);
    and gate3 (w2, A, B);
    and gate4 (w3, B, Cin);
    and gate5 (w4, A, Cin);
    or  gate6 (Cout, w2, w3, w4);
endmodule

Gate-Level Testbench

module testbench_gate_level();
    reg A, B, Cin;
    wire Sum, Cout;

    // Instantiate the full adder
    full_adder_gate_level uut (A, B, Cin, Sum, Cout);

    // Apply test vectors
    initial begin
        A = 0; B = 0; Cin = 0; #10;
        A = 0; B = 0; Cin = 1; #10;
        A = 0; B = 1; Cin = 0; #10;
        A = 0; B = 1; Cin = 1; #10;
        A = 1; B = 0; Cin = 0; #10;
        A = 1; B = 0; Cin = 1; #10;
        A = 1; B = 1; Cin = 0; #10;
        A = 1; B = 1; Cin = 1; #10;
    end
  initial $monitor($time, "%b, %b", Sum, Cout);
  initial #100 $stop;
endmodule

Dataflow Modeling

module full_adder_dataflow(input A, input B, input Cin, output Sum, output Cout);
    assign Sum = A ^ B ^ Cin;
    assign Cout = (A & B) | (Cin & (A ^ B));
endmodule

Dataflow Testbench

module testbench_dataflow();
    reg A, B, Cin;
    wire Sum, Cout;

    // Instantiate the full adder
    full_adder_dataflow uut (A, B, Cin, Sum, Cout);

    // Apply test vectors
    initial begin
        A = 0; B = 0; Cin = 0; #10;
        A = 0; B = 0; Cin = 1; #10;
        A = 0; B = 1; Cin = 0; #10;
        A = 0; B = 1; Cin = 1; #10;
        A = 1; B = 0; Cin = 0; #10;
        A = 1; B = 0; Cin = 1; #10;
        A = 1; B = 1; Cin = 0; #10;
        A = 1; B = 1; Cin = 1; #10;
    end
  initial $monitor($time, "%b, %b", Sum, Cout);
  initial #100 $stop;
endmodule

Behavioral Modeling

module full_adder_behavioral(input A, input B, input Cin, output Sum, output Cout);
    always @(*)
      begin
        {Cout, Sum} = A + B + Cin;
      end
endmodule

Behavioral Testbench

module testbench_behavioral();
    reg A, B, Cin;
    wire Sum, Cout;

    // Instantiate the full adder
    full_adder_behavioral uut (A, B, Cin, Sum, Cout);

    // Apply test vectors
    initial begin
        A = 0; B = 0; Cin = 0; #10;
        A = 0; B = 0; Cin = 1; #10;
        A = 0; B = 1; Cin = 0; #10;
        A = 0; B = 1; Cin = 1; #10;
        A = 1; B = 0; Cin = 0; #10;
        A = 1; B = 0; Cin = 1; #10;
        A = 1; B = 1; Cin = 0; #10;
        A = 1; B = 1; Cin = 1; #10;
    end
  initial $monitor($time, "%b, %b", Sum, Cout);
  initial #100 $stop;
endmodule

4-bit adder implemented using 1-bit full adder modules:

Gate-Level Modeling

module four_bit_adder_gate_level(
    input [3:0] A,
    input [3:0] B,
    input Cin,
    output [3:0] Sum,
    output Cout
);
    wire [3:0] w1;
    wire w2, w3, w4, w5;

    // Instantiate 1-bit full adders
    full_adder_gate_level fa0 (A[0], B[0], Cin, Sum[0], w2);
    full_adder_gate_level fa1 (A[1], B[1], w2, Sum[1], w3);
    full_adder_gate_level fa2 (A[2], B[2], w3, Sum[2], w4);
    full_adder_gate_level fa3 (A[3], B[3], w4, Sum[3], w5);

    // Calculate final carry out
    or gate1 (Cout, w5, w5, w5, w5);
endmodule

Gate-Level Testbench

module testbench_four_bit_adder_gate_level();
    reg [3:0] A, B;
    reg Cin;
    wire [3:0] Sum;
    wire Cout;

    // Instantiate the 4-bit adder
    four_bit_adder_gate_level uut (A, B, Cin, Sum, Cout);

    // Apply test vectors
    initial begin
        A = 4'b0000; B = 4'b0000; Cin = 0; #10;
        A = 4'b0001; B = 4'b0001; Cin = 0; #10;
        A = 4'b0010; B = 4'b0010; Cin = 1; #10;
        A = 4'b0100; B = 4'b0100; Cin = 0; #10;
        A = 4'b1000; B = 4'b1000; Cin = 1; #10;
        A = 4'b1111; B = 4'b1111; Cin = 1; #10;
    end
  initial $monitor($time, "%b, %b", Sum, Cout);
  initial #100 $stop;
endmodule

Dataflow Modeling

module four_bit_adder_dataflow(
    input [3:0] A,
    input [3:0] B,
    input Cin,
    output [3:0] Sum,
    output Cout
);
    wire w1;

    // Instantiate 1-bit full adders
    full_adder_dataflow fa0 (A[0], B[0], Cin, Sum[0], w1);
    full_adder_dataflow fa1 (A[1], B[1], w1, Sum[1], w1);
    full_adder_dataflow fa2 (A[2], B[2], w1, Sum[2], w1);
    full_adder_dataflow fa3 (A[3], B[3], w1, Sum[3], Cout);
endmodule

Dataflow Testbench

module testbench_four_bit_adder_dataflow();
    reg [3:0] A, B;
    reg Cin;
    wire [3:0] Sum;
    wire Cout;

    // Instantiate the 4-bit adder
    four_bit_adder_dataflow uut (A, B, Cin, Sum, Cout);

    // Apply test vectors
    initial begin
        A = 4'b0000; B = 4'b0000; Cin = 0; #10;
        A = 4'b0001; B = 4'b0001; Cin = 0; #10;
        A = 4'b0010; B = 4'b0010; Cin = 1; #10;
        A = 4'b0100; B = 4'b0100; Cin = 0; #10;
        A = 4'b1000; B = 4'b1000; Cin = 1; #10;
        A = 4'b1111; B = 4'b1111; Cin = 1; #10;
    end
  initial $monitor($time, "%b, %b", Sum, Cout);
  initial #100 $stop;
endmodule

Behavioral Modeling

module four_bit_adder_behavioral(
    input [3:0] A,
    input [3:0] B,
    input Cin,
    output [3:0] Sum,
    output Cout
);
    reg [3:0] w1;

    // Instantiate 1-bit full adders
    always @* begin
        full_adder_behavioral fa0 (A[0], B[0], Cin, Sum[0], w1[0]);
        full_adder_behavioral fa1 (A[1], B[1], w1[0], Sum[1], w1[1]);
        full_adder_behavioral fa2 (A[2], B[2], w1[1], Sum[2], w1[2]);
        full_adder_behavioral fa3 (A[3], B[3], w1[2], Sum[3], Cout);
    end
endmodule

Behavioral Testbench

module testbench_four_bit_adder_behavioral();
    reg [3:0] A, B;
    reg Cin;
    wire [3:0] Sum;
    wire Cout;

    // Instantiate the 4-bit adder
    four_bit_adder_behavioral uut (A, B, Cin, Sum, Cout);

    // Apply test vectors
    initial begin
        A = 4'b0000; B = 4'b0000; Cin = 0; #10;
        A = 4'b0001; B = 4'b0001; Cin = 0; #10;
        A = 4'b0010; B = 4'b0010; Cin = 1; #10;
        A = 4'b0100; B = 4'b0100; Cin = 0; #10;
        A = 4'b1000; B = 4'b1000; Cin = 1; #10;
        A = 4'b1111; B = 4'b1111; Cin = 1; #10;
    end
  initial $monitor($time, "%b, %b", Sum, Cout);
  initial #100 $stop;
endmodule

4-to-1 Multiplexer (MUX) Implementation in Verilog

Gate-Level Modeling

module mux_gate_level(input [3:0] D, input [1:0] S, output Y);
    wire w1, w2, w3, w4;

    and gate1 (w1, D[0], ~S[0]);
    and gate2 (w2, D[1], S[0]);
    and gate3 (w3, D[2], ~S[1]);
    and gate4 (w4, D[3], S[1]);
    or  gate5 (Y, w1, w2, w3, w4);
endmodule

Gate-Level Testbench

module testbench_mux_gate_level();
    reg [3:0] D;
    reg [1:0] S;
    wire Y;

    // Instantiate the MUX
    mux_gate_level uut (D, S, Y);

    // Apply test vectors
    initial begin
        D = 4'b0000; S = 2'b00; #10; // Select input 0
        D = 4'b1111; S = 2'b00; #10; // Select input 0
        D = 4'b0000; S = 2'b01; #10; // Select input 1
        D = 4'b1111; S = 2'b01; #10; // Select input 1
        D = 4'b0000; S = 2'b10; #10; // Select input 2
        D = 4'b1111; S = 2'b10; #10; // Select input 2
        D = 4'b0000; S = 2'b11; #10; // Select input 3
        D = 4'b1111; S = 2'b11; #10; // Select input 3
    end
    initial #100 $stop;
endmodule

Dataflow Modeling

module mux_dataflow(input [3:0] D, input [1:0] S, output Y);
    assign Y = (S[1] & S[0]) ? D[3] : (S[1] & ~S[0]) ? D[2] : (~S[1] & S[0]) ? D[1] : D[0];
    // if ? (__) : else (__)
    // Cond_exp ? true_exp : false_exp
endmodule

Dataflow Testbench

module testbench_mux_dataflow();
    reg [3:0] D;
    reg [1:0] S;
    wire Y;

    // Instantiate the MUX
    mux_dataflow uut (D, S, Y);

    // Apply test vectors
    initial begin
        D = 4'b0000; S = 2'b00; #10; // Select input 0
        D = 4'b1111; S = 2'b00; #10; // Select input 0
        D = 4'b0000; S = 2'b01; #10; // Select input 1
        D = 4'b1111; S = 2'b01; #10; // Select input 1
        D = 4'b0000; S = 2'b10; #10; // Select input 2
        D = 4'b1111; S = 2'b10; #10; // Select input 2
        D = 4'b0000; S = 2'b11; #10; // Select input 3
        D = 4'b1111; S = 2'b11; #10; // Select input 3
    end
    initial #100 $stop;
endmodule

Behavioral Modeling

module mux_behavioral(input [3:0] D, input [1:0] S, output Y);
    always @ (*) begin
        case(S)
            2'b00: Y = D[0];
            2'b01: Y = D[1];
            2'b10: Y = D[2];
            2'b11: Y = D[3];
            default: Y = 4'bxxxx; // Handle invalid cases
        endcase
    end
endmodule

Behavioral Testbench

module testbench_mux_behavioral();
    reg [3:0] D;
    reg [1:0] S;
    wire Y;

    // Instantiate the MUX
    mux_behavioral uut (D, S, Y);

    // Apply test vectors
    initial begin
        D = 4'b0000; S = 2'b00; #10; // Select input 0
        D = 4'b1111; S = 2'b00; #10; // Select input 0
        D = 4'b0000; S = 2'b01; #10; // Select input 1
        D = 4'b1111; S = 2'b01; #10; // Select input 1
        D = 4'b0000; S = 2'b10; #10; // Select input 2
        D = 4'b1111; S = 2'b10; #10; // Select input 2
        D = 4'b0000; S = 2'b11; #10; // Select input 3
        D = 4'b1111; S = 2'b11; #10; // Select input 3
    end
    initial #100 $stop;
endmodule

Certainly! Here's the Markdown (.md) file containing Verilog code for a 2-to-4 decoder implemented using gate-level, dataflow, and behavioral modeling, along with their respective testbenches.

2-to-4 Decoder Implementation in Verilog

Gate-Level Modeling

module decoder_2to4_gate_level(input [1:0] A, output [3:0] Y);
    wire w0, w1, w2, w3;

    and gate1 (w0, ~A[0], ~A[1]);
    and gate2 (w1, ~A[0], A[1]);
    and gate3 (w2, A[0], ~A[1]);
    and gate4 (w3, A[0], A[1]);

    assign Y = {w3, w2, w1, w0};
endmodule

Gate-Level Testbench

module testbench_gate_level_decoder();
    reg [1:0] A;
    wire [3:0] Y;

    // Instantiate the decoder
    decoder_2to4_gate_level uut (A, Y);

    // Apply test vectors
    initial begin
        $dumpfile("gate_level_decoder.vcd");
        $dumpvars(0, testbench_gate_level_decoder);

        A = 2'b00; #10;
        A = 2'b01; #10;
        A = 2'b10; #10;
        A = 2'b11; #10;

        $finish;
    end
endmodule

Dataflow Modeling

module decoder_2to4_dataflow(input [1:0] A, output [3:0] Y);
    assign Y[0] = ~A[0] & ~A[1];
    assign Y[1] = ~A[0] & A[1];
    assign Y[2] = A[0] & ~A[1];
    assign Y[3] = A[0] & A[1];
endmodule

Dataflow Testbench

module testbench_dataflow_decoder();
    reg [1:0] A;
    wire [3:0] Y;

    // Instantiate the decoder
    decoder_2to4_dataflow uut (A, Y);

    // Apply test vectors
    initial begin
        $dumpfile("dataflow_decoder.vcd");
        $dumpvars(0, testbench_dataflow_decoder);

        A = 2'b00; #10;
        A = 2'b01; #10;
        A = 2'b10; #10;
        A = 2'b11; #10;

        $finish;
    end
endmodule

Behavioral Modeling

module decoder_2to4_behavioral(input [1:0] A, output [3:0] Y);
    always @* begin
        Y[0] = ~A[0] & ~A[1];
        Y[1] = ~A[0] & A[1];
        Y[2] = A[0] & ~A[1];
        Y[3] = A[0] & A[1];
    end
endmodule

Behavioral Testbench

module testbench_behavioral_decoder();
    reg [1:0] A;
    wire [3:0] Y;

    // Instantiate the decoder
    decoder_2to4_behavioral uut (A, Y);

    // Apply test vectors
    initial begin
        $dumpfile("behavioral_decoder.vcd");
        $dumpvars(0, testbench_behavioral_decoder);

        A = 2'b00; #10;
        A = 2'b01; #10;
        A = 2'b10; #10;
        A = 2'b11; #10;

        $finish;
    end
endmodule

Certainly! Below is the Verilog code for a parity generator implemented using dataflow modeling:

module parity_generator_dataflow(input [7:0] data, output P);
    assign P = ^data;
endmodule

In this code, we define a module named parity_generator_dataflow with an 8-bit input data and a single-bit output P. The ^ operator performs a bitwise XOR operation on all the bits in data, generating the parity bit P.

Here's a simple testbench to verify the functionality of the parity generator:

module testbench_parity_generator();
    reg [7:0] data;
    wire P;

    // Instantiate the parity generator
    parity_generator_dataflow uut (data, P);

    // Apply test vectors
    initial begin
        $dumpfile("parity_generator.vcd");
        $dumpvars(0, testbench_parity_generator);

        data = 8'b00000000; #10; // Even parity, P = 0
        data = 8'b10101010; #10; // Even parity, P = 0
        data = 8'b01010101; #10; // Even parity, P = 0
        data = 8'b11111111; #10; // Even parity, P = 0

        data = 8'b00000001; #10; // Odd parity, P = 1
        data = 8'b10101011; #10; // Odd parity, P = 1
        data = 8'b01010100; #10; // Odd parity, P = 1
        data = 8'b11111110; #10; // Odd parity, P = 1

        $finish;
    end
endmodule

In this testbench, we apply various test vectors to the data input and check the output P to verify if the parity generator is functioning correctly. The expected outputs are commented next to each test vector.

Certainly! Here are the implementations of an 8-to-1 MUX and a 3-to-8 Decoder using dataflow modeling along with their respective testbenches:

8-to-1 MUX in Dataflow Modeling

module mux_8to1_dataflow(input [7:0] D, input [2:0] S, output Y);
    assign Y = (S == 3'b000) ? D[0] :
              (S == 3'b001) ? D[1] :
              (S == 3'b010) ? D[2] :
              (S == 3'b011) ? D[3] :
              (S == 3'b100) ? D[4] :
              (S == 3'b101) ? D[5] :
              (S == 3'b110) ? D[6] :
                              D[7];
endmodule

8-to-1 MUX Testbench

module testbench_mux_8to1_dataflow();
    reg [7:0] D;
    reg [2:0] S;
    wire Y;

    // Instantiate the 8-to-1 MUX
    mux_8to1_dataflow uut (D, S, Y);

    // Apply test vectors
    initial begin
        $dumpfile("mux_8to1_dataflow.vcd");
        $dumpvars(0, testbench_mux_8to1_dataflow);

        D = 8'b00000000; S = 3'b000; #10; // Selecting input 0, Y = 0
        D = 8'b11111111; S = 3'b001; #10; // Selecting input 1, Y = 1
        D = 8'b10101010; S = 3'b010; #10; // Selecting input 2, Y = 0
        D = 8'b11001100; S = 3'b011; #10; // Selecting input 3, Y = 0
        D = 8'b01010101; S = 3'b100; #10; // Selecting input 4, Y = 0
        D = 8'b00110011; S = 3'b101; #10; // Selecting input 5, Y = 1
        D = 8'b00001111; S = 3'b110; #10; // Selecting input 6, Y = 1
        D = 8'b11110000; S = 3'b111; #10; // Selecting input 7, Y = 0

        $finish;
    end
endmodule

3-to-8 Decoder in Dataflow Modeling

module decoder_3to8_dataflow(input [2:0] A, output [7:0] Y);
    assign Y[0] = (A == 3'b000) ? 1'b1 : 1'b0;
    assign Y[1] = (A == 3'b001) ? 1'b1 : 1'b0;
    assign Y[2] = (A == 3'b010) ? 1'b1 : 1'b0;
    assign Y[3] = (A == 3'b011) ? 1'b1 : 1'b0;
    assign Y[4] = (A == 3'b100) ? 1'b1 : 1'b0;
    assign Y[5] = (A == 3'b101) ? 1'b1 : 1'b0;
    assign Y[6] = (A == 3'b110) ? 1'b1 : 1'b0;
    assign Y[7] = (A == 3'b111) ? 1'b1 : 1'b0;
endmodule

3-to-8 Decoder Testbench

module testbench_decoder_3to8_dataflow();
    reg [2:0] A;
    wire [7:0] Y;

    // Instantiate the 3-to-8 Decoder
    decoder_3to8_dataflow uut (A, Y);

    // Apply test vectors
    initial begin
        $dumpfile("decoder_3to8_dataflow.vcd");
        $dumpvars(0, testbench_decoder_3to8_dataflow);

        A = 3'b000; #10; // Y = 00000001
        A = 3'b001; #10; // Y = 00000010
        A = 3'b010; #10; // Y = 00000100
        A = 3'b011; #10; // Y = 00001000
        A = 3'b100; #10; // Y = 00010000
        A = 3'b101; #10; // Y = 00100000
        A = 3'b110; #10; // Y = 01000000
        A = 3'b111; #10; // Y = 10000000

        $finish;
    end
endmodule

Sure! Below are implementations of different types of 4-bit counters (Up-counter, Down-counter, Up/Down-counter, and Johnson counter) using behavioral modeling, along with their respective testbenches.

4-Bit Up-Counter

module up_counter(input clk, input rst, output reg [3:0] count);
    always @(posedge clk or posedge rst) begin
        if (rst)
            count <= 4'b0000;
        else
            count <= count + 1;
    end
endmodule

Up-Counter Testbench

module testbench_up_counter();
    reg clk, rst;
    wire [3:0] count;

    // Instantiate the up-counter
    up_counter uut (clk, rst, count);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("up_counter.vcd");
        $dumpvars(0, testbench_up_counter);

        // Reset
        rst = 1;
        #10 rst = 0;

        // Count for 20 clock cycles
        repeat(20) #10;

        $finish;
    end
endmodule

4-Bit Down-Counter

module down_counter(input clk, input rst, output reg [3:0] count);
    always @(posedge clk or posedge rst) begin
        if (rst)
            count <= 4'b1111;
        else
            count <= count - 1;
    end
endmodule

Down-Counter Testbench

module testbench_down_counter();
    reg clk, rst;
    wire [3:0] count;

    // Instantiate the down-counter
    down_counter uut (clk, rst, count);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("down_counter.vcd");
        $dumpvars(0, testbench_down_counter);

        // Reset
        rst = 1;
        #10 rst = 0;

        // Count for 20 clock cycles
        repeat(20) #10;

        $finish;
    end
endmodule

4-Bit Up/Down-Counter

module up_down_counter(input clk, input up, input down, input rst, output reg [3:0] count);
    always @(posedge clk or posedge rst) begin
        if (rst)
            count <= 4'b0000;
        else if (up)
            count <= count + 1;
        else if (down)
            count <= count - 1;
    end
endmodule

Up/Down-Counter Testbench

module testbench_up_down_counter();
    reg clk, up, down, rst;
    wire [3:0] count;

    // Instantiate the up/down-counter
    up_down_counter uut (clk, up, down, rst, count);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("up_down_counter.vcd");
        $dumpvars(0, testbench_up_down_counter);

        // Reset
        rst = 1;
        #10 rst = 0;

        // Count up for 10 clock cycles
        up = 1;
        repeat(10) #10;
        up = 0;

        // Count down for 10 clock cycles
        down = 1;
        repeat(10) #10;
        down = 0;

        $finish;
    end
endmodule

4-Bit Johnson Counter

module johnson_counter(input clk, input rst, output reg [3:0] count);
    always @(posedge clk or posedge rst) begin
        if (rst)
            count <= 4'b0001;
        else begin
            count <= {count[2:0], count[3]};
        end
    end
endmodule

Johnson Counter Testbench

module testbench_johnson_counter();
    reg clk, rst;
    wire [3:0] count;

    // Instantiate the Johnson counter
    johnson_counter uut (clk, rst, count);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("johnson_counter.vcd");
        $dumpvars(0, testbench_johnson_counter);

        // Reset
        rst = 1;
        #10 rst = 0;

        // Count for 16 clock cycles
        repeat(16) #10;

        $finish;
    end
endmodule

You can save each module in separate files (e.g., up_counter.v, down_counter.v, up_down_counter.v, johnson_counter.v)

Certainly! I'll provide you with the Verilog code for each of the components you've requested, along with their respective testbenches.

1. 4-bit Binary Counter (Behavioral Modeling) with Testbench

module binary_counter_4bit_behavioral(input clk, input rst, output reg [3:0] count);
    always @(posedge clk or posedge rst) begin
        if (rst) begin
            count <= 4'b0000;
        end else begin
            count <= count + 1;
        end
    end
endmodule

Testbench for 4-bit Binary Counter:

module testbench_binary_counter_4bit_behavioral();
    reg clk, rst;
    reg [3:0] count;

    // Instantiate the binary counter
    binary_counter_4bit_behavioral uut (clk, rst, count);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("binary_counter_4bit_behavioral.vcd");
        $dumpvars(0, testbench_binary_counter_4bit_behavioral);

        // Initialize signals
        clk = 0; rst = 0;

        // Reset and check initial value
        rst = 1; #10; rst = 0; #10;
        if (count !== 4'b0000) $fatal("Initial value incorrect");

        // Count up to 15
        rst = 0; #10; // Release reset
        if (count !== 4'b0001) $fatal("Value after 1st clock cycle incorrect");
        #10; if (count !== 4'b0010) $fatal("Value after 2nd clock cycle incorrect");
        #10; if (count !== 4'b0011) $fatal("Value after 3rd clock cycle incorrect");
        #10; if (count !== 4'b0100) $fatal("Value after 4th clock cycle incorrect");
        #10; if (count !== 4'b0101) $fatal("Value after 5th clock cycle incorrect");
        #10; if (count !== 4'b0110) $fatal("Value after 6th clock cycle incorrect");
        #10; if (count !== 4'b0111) $fatal("Value after 7th clock cycle incorrect");
        #10; if (count !== 4'b1000) $fatal("Value after 8th clock cycle incorrect");
        #10; if (count !== 4'b1001) $fatal("Value after 9th clock cycle incorrect");
        #10; if (count !== 4'b1010) $fatal("Value after 10th clock cycle incorrect");
        #10; if (count !== 4'b1011) $fatal("Value after 11th clock cycle incorrect");
        #10; if (count !== 4'b1100) $fatal("Value after 12th clock cycle incorrect");
        #10; if (count !== 4'b1101) $fatal("Value after 13th clock cycle incorrect");
        #10; if (count !== 4'b1110) $fatal("Value after 14th clock cycle incorrect");
        #10; if (count !== 4'b1111) $fatal("Value after 15th clock cycle incorrect");

        // Finish simulation
        $finish;
    end
endmodule

2. 3 to 8 Decoder (Behavioral Modeling) with Testbench

module decoder_3to8_behavioral(input [2:0] A, output [7:0] Y);
    assign Y[0] = (A == 3'b000) ? 1'b1 : 1'b0;
    assign Y[1] = (A == 3'b001) ? 1'b1 : 1'b0;
    assign Y[2] = (A == 3'b010) ? 1'b1 : 1'b0;
    assign Y[3] = (A == 3'b011) ? 1'b1 : 1'b0;
    assign Y[4] = (A == 3'b100) ? 1'b1 : 1'b0;
    assign Y[5] = (A == 3'b101) ? 1'b1 : 1'b0;
    assign Y[6] = (A == 3'b110) ? 1'b1 : 1'b0;
    assign Y[7] = (A == 3'b111) ? 1'b1 : 1'b0;
endmodule

Testbench for 3 to 8 Decoder:

module testbench_decoder_3to8_behavioral();
    reg [2:0] A;
    wire [7:0] Y;

    // Instantiate the 3 to 8 Decoder
    decoder_3to8_behavioral uut (A, Y);

    // Apply test vectors
    initial begin
        $dumpfile("decoder_3to8_behavioral.vcd");
        $dumpvars(0, testbench_decoder_3to8_behavioral);

        A = 3'b000; #10; // Y = 00000001
        A = 3'b001; #10; // Y = 00000010
        A = 3'b010; #10; // Y = 00000100
        A = 3'b011; #10; // Y = 00001000
        A = 3'b100; #10; // Y = 00010000
        A = 3'b101; #10; // Y = 00100000
        A = 3'b110; #10; // Y = 01000000
        A = 3'b111; #10; // Y = 10000000

        $finish;
    end
endmodule

3. 4-bit Up Down Counter (Behavioral Modeling) with Testbench

module up_down_counter_4bit_behavioral(input clk, input rst, input up, output reg [3:0] count);
    always @(posedge clk or posedge rst) begin
        if (rst) begin
            count <= 4'b0000;
        end else if (up) begin
            count <= count + 1;
        end else begin
            count <= count - 1;
        end
    end
endmodule

Testbench for 4-bit Up Down Counter:

module testbench_up_down_counter_4bit_behavioral();
    reg clk, rst, up;
    wire [3:0] count;

    // Instantiate the up down counter
    up_down_counter_4bit_behavioral uut (clk, rst, up, count);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("up_down_counter_4bit_behavioral.vcd");
        $dumpvars(0, testbench_up_down_counter_4bit_behavioral);

        // Initialize signals
        clk = 0; rst = 0; up = 0;

        //

 Reset and check initial value
        rst = 1; #10; rst = 0; #10;
        if (count !== 4'b0000) $fatal("Initial value incorrect");

        // Count up to 15
        up = 1; #10; // Set direction to up
        if (count !== 4'b0001) $fatal("Value after 1st clock cycle incorrect");
        #10; if (count !== 4'b0010) $fatal("Value after 2nd clock cycle incorrect");
        #10; if (count !== 4'b0011) $fatal("Value after 3rd clock cycle incorrect");

        // Count down to 0
        up = 0; #10; // Set direction to down
        if (count !== 4'b0010) $fatal("Value after 4th clock cycle incorrect");
        #10; if (count !== 4'b0001) $fatal("Value after 5th clock cycle incorrect");
        #10; if (count !== 4'b0000) $fatal("Value after 6th clock cycle incorrect");

        // Finish simulation
        $finish;
    end
endmodule

4. 4-bit Ring Counter (Behavioral Modeling) with Testbench

module ring_counter_4bit_behavioral(input clk, input rst, output reg [3:0] count);
    always @(posedge clk or posedge rst) begin
        if (rst) begin
            count <= 4'b0001;
        end else begin
            count <= {count[2:0], count[3]};
        end
    end
endmodule

Testbench for 4-bit Ring Counter:

module testbench_ring_counter_4bit_behavioral();
    reg clk, rst;
    wire [3:0] count;

    // Instantiate the ring counter
    ring_counter_4bit_behavioral uut (clk, rst, count);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("ring_counter_4bit_behavioral.vcd");
        $dumpvars(0, testbench_ring_counter_4bit_behavioral);

        // Initialize signals
        clk = 0; rst = 0;

        // Reset and check initial value
        rst = 1; #10; rst = 0; #10;
        if (count !== 4'b0001) $fatal("Initial value incorrect");

        // Count for a few cycles
        #10; if (count !== 4'b0010) $fatal("Value after 1st clock cycle incorrect");
        #10; if (count !== 4'b0100) $fatal("Value after 2nd clock cycle incorrect");
        #10; if (count !== 4'b1000) $fatal("Value after 3rd clock cycle incorrect");
        #10; if (count !== 4'b0001) $fatal("Value after 4th clock cycle incorrect");
        #10; if (count !== 4'b0010) $fatal("Value after 5th clock cycle incorrect");

        // Finish simulation
        $finish;
    end
endmodule

5. 8-bit ALU (Behavioral Modeling) with Testbench

module alu_8bit_behavioral(input [7:0] A, input [7:0] B, input [2:0] opcode,
                           output reg [7:0] result);
    always @* begin
        case(opcode)
            3'b000: result = A + B; // Add operation
            3'b001: result = A - B; // Subtract operation
            3'b010: result = A & B; // Bit-wise AND operation
            3'b011: result = A | B; // Bit-wise OR operation
            default: result = 8'b00000000; // Default case
        endcase
    end
endmodule

Testbench for 8-bit ALU:

module testbench_alu_8bit_behavioral();
    reg [7:0] A, B;
    reg [2:0] opcode;
    wire [7:0] result;

    // Instantiate the 8-bit ALU
    alu_8bit_behavioral uut (A, B, opcode, result);

    // Apply test vectors
    initial begin
        $dumpfile("alu_8bit_behavioral.vcd");
        $dumpvars(0, testbench_alu_8bit_behavioral);

        // Test addition
        A = 8'b01010101; B = 8'b10101010; opcode = 3'b000; #10;
        if (result !== 8'b00000000) $fatal("Addition operation incorrect");

        // Test subtraction
        A = 8'b01010101; B = 8'b10101010; opcode = 3'b001; #10;
        if (result !== 8'b11111111) $fatal("Subtraction operation incorrect");

        // Test bit-wise AND
        A = 8'b01010101; B = 8'b10101010; opcode = 3'b010; #10;
        if (result !== 8'b00000000) $fatal("Bit-wise AND operation incorrect");

        // Test bit-wise OR
        A = 8'b01010101; B = 8'b10101010; opcode = 3'b011; #10;
        if (result !== 8'b11111111) $fatal("Bit-wise OR operation incorrect");

        // Finish simulation
        $finish;
    end
endmodule

6. BCD to Seven Segment Decoder (Behavioral Modeling)

module bcd_to_seven_segment_behavioral(input [3:0] BCD, output reg [6:0] seg_display);
    always @* begin
        case(BCD)
            4'b0000: seg_display = 7'b1000000; // 0
            4'b0001: seg_display = 7'b1111001; // 1
            4'b0010: seg_display = 7'b0100100; // 2
            4'b0011: seg_display = 7'b0110000; // 3
            4'b0100: seg_display = 7'b0011001; // 4
            4'b0101: seg_display = 7'b0010010; // 5
            4'b0110: seg_display = 7'b0000010; // 6
            4'b0111: seg_display = 7'b1111000; // 7
            4'b1000: seg_display = 7'b0000000; // 8
            4'b1001: seg_display = 7'b0010000; // 9
            default: seg_display = 7'b1111111; // Default case (All segments off)
        endcase
    end
endmodule

Certainly! Here's the Verilog code for a 4-bit Ring Counter implemented using behavioral modeling, along with its testbench:

module ring_counter_4bit_behavioral(input clk, input rst, output reg [3:0] count);
    always @(posedge clk or posedge rst) begin
        if (rst) begin
            count <= 4'b0001;
        end else begin
            count <= {count[2:0], count[3]};
        end
    end
endmodule

Testbench for the 4-bit Ring Counter:

module testbench_ring_counter_4bit_behavioral();
    reg clk, rst;
    wire [3:0] count;

    // Instantiate the ring counter
    ring_counter_4bit_behavioral uut (clk, rst, count);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("ring_counter_4bit_behavioral.vcd");
        $dumpvars(0, testbench_ring_counter_4bit_behavioral);

        // Initialize signals
        clk = 0; rst = 0;

        // Reset and check initial value
        rst = 1; #10; rst = 0; #10;
        if (count !== 4'b0001) $fatal("Initial value incorrect");

        // Count for a few cycles
        #10; if (count !== 4'b0010) $fatal("Value after 1st clock cycle incorrect");
        #10; if (count !== 4'b0100) $fatal("Value after 2nd clock cycle incorrect");
        #10; if (count !== 4'b1000) $fatal("Value after 3rd clock cycle incorrect");
        #10; if (count !== 4'b0001) $fatal("Value after 4th clock cycle incorrect");
        #10; if (count !== 4'b0010) $fatal("Value after 5th clock cycle incorrect");

        // Finish simulation
        $finish;
    end
endmodule

In this example, the 4-bit Ring Counter is implemented using behavioral modeling. It consists of a module named ring_counter_4bit_behavioral with an input clock (clk), reset (rst), and a 4-bit output counter (count). The counter shifts its bits to the left on each clock cycle, effectively creating a ring-like behavior.

The testbench applies clock and reset signals and checks the counter's behavior by monitoring its output. The simulation generates a VCD file for waveform viewing.

Save the module and testbench in separate files (e.g., ring_counter_4bit_behavioral.v and testbench_ring_counter_4bit_behavioral.v). Use a simulator like XSIM or ModelSim to run the testbench and observe the counter's behavior.

Certainly! Below is the Verilog code for a 4-bit down counter implemented using behavioral modeling. It includes a clock (clk), reset (rst), and a 4-bit output counter (count). The counter counts down by 1 on each rising edge of the clock, and can be reset to its initial value by asserting the reset signal.

module down_counter_4bit_behavioral(input clk, input rst, output reg [3:0] count);
    always @(posedge clk or posedge rst) begin
        if (rst) begin
            count <= 4'b1111;
        end else begin
            count <= count - 1;
        end
    end
endmodule

Next, we'll implement the 7-segment display decoder. The display will be updated based on the value of the 4-bit counter.

module bcd_to_seven_segment_behavioral(input [3:0] BCD, output reg [6:0] seg_display);
    always @* begin
        case(BCD)
            4'b0000: seg_display = 7'b1000000; // 0
            4'b0001: seg_display = 7'b1111001; // 1
            4'b0010: seg_display = 7'b0100100; // 2
            4'b0011: seg_display = 7'b0110000; // 3
            4'b0100: seg_display = 7'b0011001; // 4
            4'b0101: seg_display = 7'b0010010; // 5
            4'b0110: seg_display = 7'b0000010; // 6
            4'b0111: seg_display = 7'b1111000; // 7
            4'b1000: seg_display = 7'b0000000; // 8
            4'b1001: seg_display = 7'b0010000; // 9
            default: seg_display = 7'b1111111; // Default case (All segments off)
        endcase
    end
endmodule

Now, let's create the testbench that will provide clock and reset signals to the counter and display the count on a 7-segment display.

module testbench_down_counter_7seg_behavioral();
    reg clk, rst;
    wire [3:0] count;
    reg [6:0] seg_display;

    // Instantiate the down counter
    down_counter_4bit_behavioral uut_counter (clk, rst, count);

    // Instantiate the 7-segment display decoder
    bcd_to_seven_segment_behavioral uut_7seg (count, seg_display);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("down_counter_7seg_behavioral.vcd");
        $dumpvars(0, testbench_down_counter_7seg_behavioral);

        // Initialize signals
        clk = 0; rst = 0;

        // Reset and check initial value
        rst = 1; #10; rst = 0; #10;
        if (count !== 4'b1111) $fatal("Initial value incorrect");

        // Count down for a few cycles
        #10; if (count !== 4'b1110) $fatal("Value after 1st clock cycle incorrect");
        #10; if (count !== 4'b1101) $fatal("Value after 2nd clock cycle incorrect");
        #10; if (count !== 4'b1100) $fatal("Value after 3rd clock cycle incorrect");

        // Finish simulation
        $finish;
    end
endmodule

In this testbench, we apply clock and reset signals, and monitor the counter's value. We also instantiate the 7-segment display decoder to display the count. The simulation generates a VCD file for waveform viewing.

Save the modules and testbench in separate files (e.g., down_counter_4bit_behavioral.v, bcd_to_seven_segment_behavioral.v, testbench_down_counter_7seg_behavioral.v). Use a simulator like XSIM or ModelSim to run the testbench and observe the counter's behavior on the 7-segment display.

Certainly! Below are the Verilog modules for the components you requested, implemented using behavioral modeling, along with their respective testbenches:

1. Shift Register

module shift_register_behavioral(input clk, input rst_n, input [7:0] data_in, output reg [7:0] data_out);
    reg [7:0] shift_reg;

    always @(posedge clk or negedge rst_n) begin
        if (~rst_n) begin
            shift_reg <= 8'b0;
        end else begin
            shift_reg <= {shift_reg[6:0], data_in};
        end
    end

    assign data_out = shift_reg;
endmodule

Testbench for Shift Register

module testbench_shift_register_behavioral();
    reg clk, rst_n;
    reg [7:0] data_in;
    wire [7:0] data_out;

    // Instantiate the shift register
    shift_register_behavioral uut (clk, rst_n, data_in, data_out);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("shift_register_behavioral.vcd");
        $dumpvars(0, testbench_shift_register_behavioral);

        // Initialize signals
        clk = 0; rst_n = 1; data_in = 8'b10101010;

        // Reset and check initial value
        rst_n = 0; #10; rst_n = 1; #10;
        if (data_out !== 8'b00000000) $fatal("Initial value incorrect");

        // Shift in data
        data_in = 8'b11110000; #10;
        if (data_out !== 8'b00000001) $fatal("Value after 1st shift cycle incorrect");
        data_in = 8'b00111100; #10;
        if (data_out !== 8'b00000011) $fatal("Value after 2nd shift cycle incorrect");
        data_in = 8'b00001111; #10;
        if (data_out !== 8'b00000110) $fatal("Value after 3rd shift cycle incorrect");
        data_in = 8'b10000000; #10;
        if (data_out !== 8'b00001100) $fatal("Value after 4th shift cycle incorrect");

        // Finish simulation
        $finish;
    end
endmodule

2. Shift Register with Parallel Load

module shift_register_parallel_load_behavioral(input clk, input rst_n, input [7:0] data_in,
                                               input load, output reg [7:0] data_out);
    reg [7:0] shift_reg;

    always @(posedge clk or negedge rst_n) begin
        if (~rst_n) begin
            shift_reg <= 8'b0;
        end else if (load) begin
            shift_reg <= data_in;
        end else begin
            shift_reg <= {shift_reg[6:0], data_in};
        end
    end

    assign data_out = shift_reg;
endmodule

Testbench for Shift Register with Parallel Load

module testbench_shift_register_parallel_load_behavioral();
    reg clk, rst_n, load;
    reg [7:0] data_in;
    wire [7:0] data_out;

    // Instantiate the shift register with parallel load
    shift_register_parallel_load_behavioral uut (clk, rst_n, data_in, load, data_out);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("shift_register_parallel_load_behavioral.vcd");
        $dumpvars(0, testbench_shift_register_parallel_load_behavioral);

        // Initialize signals
        clk = 0; rst_n = 1; load = 0; data_in = 8'b10101010;

        // Reset and check initial value
        rst_n = 0; #10; rst_n = 1; #10;
        if (data_out !== 8'b00000000) $fatal("Initial value incorrect");

        // Load data
        load = 1; #10; load = 0; #10;
        if (data_out !== 8'b10101010) $fatal("Value after 1st load cycle incorrect");

        // Shift in data
        data_in = 8'b11110000; #10;
        if (data_out !== 8'b01010101) $fatal("Value after 1st shift cycle incorrect");
        data_in = 8'b00111100; #10;
        if (data_out !== 8'b10001111) $fatal("Value after 2nd shift cycle incorrect");

        // Finish simulation
        $finish;
    end
endmodule

3. 8-bit Johnson Counter

module johnson_counter_8bit_behavioral(input clk, input rst_n, output reg [7:0] count);
    always @(posedge clk or negedge rst_n) begin
        if (~rst_n) begin
            count <= 8'b00000001;
        end else begin
            count <= {count[6:0], ~count[7]};
        end
    end
endmodule

Testbench for 8-bit Johnson Counter

module testbench_johnson_counter_8bit_behavioral();
    reg clk, rst_n;
    wire [7:0] count;

    // Instantiate the 8-bit Johnson counter
    johnson_counter_8bit_behavioral uut (clk, rst_n, count);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("johnson_counter_8bit_behavioral.vcd");
        $dumpvars(0, testbench_johnson_counter_8bit_behavioral);

        // Initialize signals
        clk = 0; rst_n = 1;

        // Reset and check initial value
        rst_n = 0; #10; rst_n = 1; #10;
        if (count !== 8'b00000001) $fatal("Initial value incorrect");

        // Cycle through Johnson counter states
        #10; if (count !== 8'b00000010) $fatal("Value after 1st clock cycle incorrect");
        #10; if (count !== 8'b00000100) $fatal("Value after 2nd clock cycle incorrect");
        #10; if (count !== 8'b00001000) $fatal("Value after 3rd clock cycle incorrect");
        #10; if (count !== 8'b00010000) $fatal("Value after 4th clock cycle incorrect");
        #10; if (count !== 8'b00100000) $fatal("Value after 5th clock cycle incorrect");
        #10; if (count !== 8'b01000000) $fatal("Value after 6th clock cycle incorrect");
        #

10; if (count !== 8'b10000000) $fatal("Value after 7th clock cycle incorrect");
        #10; if (count !== 8'b00000001) $fatal("Value after 8th clock cycle incorrect");

        // Finish simulation
        $finish;
    end
endmodule

4. Universal Shift Register

module universal_shift_register_behavioral(input clk, input rst_n, input shift_left, input shift_right,
                                          input [7:0] data_in, output reg [7:0] data_out);
    reg [7:0] shift_reg;

    always @(posedge clk or negedge rst_n) begin
        if (~rst_n) begin
            shift_reg <= 8'b0;
        end else begin
            if (shift_left) begin
                shift_reg <= {shift_reg[6:0], data_in};
            end else if (shift_right) begin
                shift_reg <= {data_in, shift_reg[7:1]};
            end
        end
    end

    assign data_out = shift_reg;
endmodule

Testbench for Universal Shift Register

module testbench_universal_shift_register_behavioral();
    reg clk, rst_n, shift_left, shift_right;
    reg [7:0] data_in;
    wire [7:0] data_out;

    // Instantiate the universal shift register
    universal_shift_register_behavioral uut (clk, rst_n, shift_left, shift_right, data_in, data_out);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("universal_shift_register_behavioral.vcd");
        $dumpvars(0, testbench_universal_shift_register_behavioral);

        // Initialize signals
        clk = 0; rst_n = 1; shift_left = 0; shift_right = 0; data_in = 8'b10101010;

        // Reset and check initial value
        rst_n = 0; #10; rst_n = 1; #10;
        if (data_out !== 8'b00000000) $fatal("Initial value incorrect");

        // Shift left
        shift_left = 1; data_in = 8'b11110000; #10;
        if (data_out !== 8'b10101010) $fatal("Value after shift left incorrect");

        // Shift right
        shift_left = 0; shift_right = 1; data_in = 8'b00001111; #10;
        if (data_out !== 8'b11111010) $fatal("Value after shift right incorrect");

        // Finish simulation
        $finish;
    end
endmodule

5. Random Number Generation using Shift Register

module random_number_generator_behavioral(input clk, input rst_n, output reg [7:0] random_number);
    reg [7:0] shift_reg;

    always @(posedge clk or negedge rst_n) begin
        if (~rst_n) begin
            shift_reg <= 8'b0;
        end else begin
            shift_reg <= {shift_reg[6:0], shift_reg[7] ^ shift_reg[3]};
        end
    end

    assign random_number = shift_reg;
endmodule

Testbench for Random Number Generator using Shift Register

module testbench_random_number_generator_behavioral();
    reg clk, rst_n;
    wire [7:0] random_number;

    // Instantiate the random number generator
    random_number_generator_behavioral uut (clk, rst_n, random_number);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("random_number_generator_behavioral.vcd");
        $dumpvars(0, testbench_random_number_generator_behavioral);

        // Initialize signals
        clk = 0; rst_n = 1;

        // Reset and check initial value
        rst_n = 0; #10; rst_n = 1; #10;
        if (random_number !== 8'b00000000) $fatal("Initial value incorrect");

        // Generate random numbers
        #10; // Random number changes over time, no specific check

        // Finish simulation
        $finish;
    end
endmodule

Feel free to save each module in separate files (e.g., shift_register_behavioral.v, shift_register_parallel_load_behavioral.v, etc.) and their respective testbenches. Use a simulator like XSIM or ModelSim to run the testbenches and observe the behavior of each component.

Certainly! Below are the Verilog modules for the components you requested, along with their respective testbenches:

1. N-bit Full Adder

module n_bit_full_adder(input [N-1:0] A, input [N-1:0] B, input Cin, output [N:0] Sum, output Cout);
    assign Sum = A + B + Cin;
    assign Cout = (A[N-1] & B[N-1]) | (A[N-1] & Cin) | (B[N-1] & Cin);
endmodule

Testbench for N-bit Full Adder

module testbench_n_bit_full_adder();
    reg [3:0] A, B;
    reg Cin;
    wire [4:0] Sum;
    wire Cout;

    // Instantiate the 4-bit full adder
    n_bit_full_adder uut (A, B, Cin, Sum, Cout);

    // Apply test vectors
    initial begin
        $dumpfile("n_bit_full_adder.vcd");
        $dumpvars(0, testbench_n_bit_full_adder);

        // Test case 1
        A = 4'b0101; B = 4'b0011; Cin = 0; #10;
        if (Sum !== 5'b10000 || Cout !== 1) $fatal("Test case 1 failed");

        // Test case 2
        A = 4'b1101; B = 4'b1101; Cin = 1; #10;
        if (Sum !== 5'b11111 || Cout !== 1) $fatal("Test case 2 failed");

        // Test case 3
        A = 4'b1010; B = 4'b0110; Cin = 1; #10;
        if (Sum !== 5'b10001 || Cout !== 1) $fatal("Test case 3 failed");

        // Finish simulation
        $finish;
    end
endmodule

2. Clock Divider

module clock_divider(input clk, output reg clk_out);
    reg [24:0] count;

    always @(posedge clk) begin
        count <= count + 1;
        if (count == Divide_factor) begin
            clk_out <= ~clk_out;
            count <= 0;
        end
    end

    initial begin
        count <= 0;
    end
endmodule

Testbench for Clock Divider

module testbench_clock_divider();
    reg clk;
    wire clk_out;

    // Define clock frequency parameters
    parameter freq_in = 50_000_000; // 50 MHz
    parameter freq_out = 1; // 1 Hz
    parameter Divide_factor = freq_in / (2*freq_out);

    // Instantiate the clock divider
    clock_divider uut (clk, clk_out);

    // Apply test vectors
    initial begin
        $dumpfile("clock_divider.vcd");
        $dumpvars(0, testbench_clock_divider);

        // Generate clock pulses
        #5_000; // Run for 100 ms

        // Finish simulation
        $finish;
    end

    // Generate 50 MHz clock
    always #10 clk = ~clk;
endmodule

3. Synchronous vs. Asynchronous Reset

Synchronous Reset Behavioral Model

module synchronous_reset_behavioral(input clk, input rst_n, output reg Q);
    always @(posedge clk or negedge rst_n) begin
        if (~rst_n) begin
            Q <= 1'b0;
        end else begin
            // Your logic here
        end
    end
endmodule

Asynchronous Reset Behavioral Model

module asynchronous_reset_behavioral(input clk, input rst_n, output reg Q);
    always @(posedge clk or negedge rst_n) begin
        if (~rst_n) begin
            Q <= 1'b0;
        end else begin
            // Your logic here
        end
    end
endmodule

Testbench for Synchronous vs. Asynchronous Reset

module testbench_reset_behavioral();
    reg clk, rst_n;
    wire Q;

    // Instantiate the reset module (synchronous or asynchronous)
    // Replace `synchronous_reset_behavioral` with `asynchronous_reset_behavioral` for testing the asynchronous reset
    synchronous_reset_behavioral uut (clk, rst_n, Q);

    // Clock generation
    always #5 clk = ~clk;

    // Apply test vectors
    initial begin
        $dumpfile("reset_behavioral.vcd");
        $dumpvars(0, testbench_reset_behavioral);

        // Initialize signals
        clk = 0; rst_n = 1;

        // Reset and check behavior
        rst_n = 0; #10;
        if (Q !== 1'b0) $fatal("Reset behavior incorrect");

        // Allow some time
        #10;

        // Release reset and check behavior
        rst_n = 1; #10;
        // Your checks here

        // Finish simulation
        $finish;
    end
endmodule

Please replace the comment // Your logic here in the synchronous and asynchronous reset modules with your specific logic for each case. Additionally, adjust the testbench to include your specific checks for the behavior after the reset is released.