You are an expert Verilog hardware designer working on a complete FPGA or ASIC project. You are given the full source code of a Verilog project. One of the modules in the project is incomplete — its implementation is missing and marked with:

// >>> Module Implementation Begin

// <<< Module Implementation End

Your task is to complete the missing implementation so that the entire project functions correctly. You must infer what the missing module or logic is supposed to do by analyzing the rest of the codebase: module names, signal connections, instantiations, comments, and usage patterns.

Follow these rules:

1. Only generate Verilog code to go between the `// >>> Module Implementation Begin` and `// <<< Module Implementation End` comments.
2. Use Verilog-2001 syntax. Ensure the code is synthesizable.
3. Assume the goal is a working, integrated hardware design — your code must make the whole system function as intended.
4. Analyze the naming, I/O ports, and how the module is instantiated or used in other parts of the project.
5. Implement correct behavior based on design context. Do not guess randomly — reason it out.
6. Avoid vendor-specific features unless explicitly required.
7. Do not output comments, explanation, or anything outside the required code region unless explicitly asked.

Your output should contain **only the Verilog code** that fits inside the marked region.

/*
 * Copyright (c) 2024 Jun-ichi OKAMURA (jun1okamura@gmail.com)
 * SPDX-License-Identifier: Apache-2.0
 */

`default_nettype none

/* verilator lint_off UNUSEDSIGNAL */

module tt_um_jun1okamura_test0 #( parameter MAX_COUNT = 16'd10_000 ) (
    input  wire [7:0] ui_in,    // Dedicated inputs - connected to the input switches
    output wire [7:0] uo_out,   // Dedicated outputs - connected to the 7 segment display
    input  wire [7:0] uio_in,   // IOs: Bidirectional Input path
    output wire [7:0] uio_out,  // IOs: Bidirectional Output path
    output wire [7:0] uio_oe,   // IOs: Bidirectional Enable path (active high: 0=input, 1=output)
    input  wire       ena,      // will go high when the design is enabled
    input  wire       clk,      // clock
    input  wire       rst_n     // reset_n - low to reset
);

    wire reset = !rst_n;
    wire [6:0] segment_out;
    wire sel0  = ui_in[0];
    wire sel1  = ui_in[1];

    // use output as 7 segments LED
    assign uo_out = {1'b0, segment_out};

    // use bidirectionals as outputs
    assign uio_oe = 8'b11111111;

    // put bottom 8 bits of second counter out on the bidirectional gpio
    // assign uio_out = counter[23:16];
    assign uio_out = lfsr[7:0];

    // external clock is 10KHz then 1Hz, so need 16 bit counter
    reg  [15:0] counter;		// 16bit main counter
    reg  [3:0]  digit;			// digit counter
    reg   	    clk2; 		    // divided clock
    reg   	    clk2d;		    // divided clock
    wire [4:0]  data;			// data
    wire [7:0]  lfsr;			// LFSR 8
	wire [15:0] compare; 		// 
    wire        strb;           //

	assign compare = sel0 == 0 ? MAX_COUNT : {3'b001,lfsr[7:0],5'b00000}; 
    assign data    = sel1 == 0 ? {1'b0, digit} : {1'b1, digit};

    always @(posedge clk or posedge reset) begin
        if (reset) begin        // if reset, set counter to 0
            clk2d   <= 1'b0;
		end else begin			// LOOP
            // Generate clk2
            clk2d   <= clk2;
		end
    end


    assign strb = clk2 ^ clk2d;

    always @(posedge clk or posedge reset) begin
        if (reset) begin        // if reset, set counter to 0
            counter <= 16'h0000;
            digit   <= 4'b0000;
            clk2    <= 1'b0;
		end else begin			// LOOP
            // if up to 10M or LFSR value
            if (counter >= compare) begin
	            clk2    <= !clk2;
                // reset counter
                counter <= 16'h0000;
                // digit <= digit + 1;
                digit   <= digit + 1'b1;
                // only count from 0 to F
				if (digit == 4'd9)
					digit <= 0;
			end else begin
                // increment counter
                counter <= counter + 1'b1;
	        end
	    end
	end

	// lfsr module circuit
	LFSR lfsr_mod(.lfsr_out(lfsr), .clk(clk), .enb(strb), .rst(reset));

	// Seven segment circuit
    DEC_7SEG seven_seg(.hex(data), .segment(segment_out));

endmodule



/*
 * Copyright (c) 2024 Jun-ichi OKAMURA
 * SPDX-License-Identifier: Apache-2.0

      -- 1 --
     |       |
     6       2
     |       |
      -- 7 --
     |       |
     5       3
     |       |
      -- 4 --
*/

module DEC_7SEG(hex, segment);
// >>> Module Implementation Begin

// <<< Module Implementation End
endmodule




/*
 * Copyright (c) 2024 Jun-ichi OKAMURA
 * SPDX-License-Identifier: Apache-2.0
 */

`default_nettype none

module LFSR (			
	output wire [7:0] lfsr_out, 
    input  wire clk,
    input  wire enb,
    input  wire rst
);
    //
	wire [7:0]  mux8;
	wire [15:0] mux16;
    // Instances
    lfsr8     sel8(.lfsr_out(mux8),  .clk(clk), .enb(enb), .rst(rst));
    lfsr16    data(.lfsr_out(mux16), .clk(clk), .enb(enb), .rst(rst));
    mux_16to8 mux1(.inputs(mux16), .sel8(mux8), .outputs(lfsr_out));

endmodule

// ======================== lfsr8 module =============================
module lfsr8 (			
	output reg  [7:0] lfsr_out, 
    input  wire clk,
    input  wire enb,
    input  wire rst
);
	//LFSR feedback
	wire   feedback;
	assign feedback = ~(lfsr_out[7] ^ lfsr_out[5] ^ lfsr_out[4] ^ lfsr_out[3]);
    //
	always @(posedge clk or posedge rst) begin
		if (rst)
			lfsr_out <= 8'h00;
		else begin
			if (enb) 
				lfsr_out <= {lfsr_out[6:0],feedback};
		end
	end
	
endmodule

// ======================== lfsr16 module =============================
module lfsr16(
	output reg  [15:0] lfsr_out, 
	input  wire clk, 
    input  wire enb,
	input  wire rst 
);
	//LFSR register block 
	wire   feedback;
	assign feedback = ~(lfsr_out[15] ^ lfsr_out[14] ^ lfsr_out[12] ^ lfsr_out[10]);
    //
	always @(posedge clk or posedge rst) begin
		if (rst)
			lfsr_out <= 16'h0000;
		else begin
			if (enb) 
				lfsr_out <= {lfsr_out[14:0],feedback};
		end
	end
  
endmodule

// ======================== mux 16 > 8 module =============================
module mux_16to8 (
    input  wire [15:0] inputs, // 16 inputs
    input  wire [7:0]  sel8,   // 8 control inputs
    output wire [7:0]  outputs // 8 outputs
);
    // 
	genvar j;
	generate
		for (j = 0; j < 8; j = j + 1) begin : mux_inst8
		    assign outputs[j] = sel8[j] ? inputs[j * 2 + 1] : inputs[j * 2];
		end
	endgenerate
    //

endmodule


Reference solution:
rtl/generated.v: 	input wire [4:0] hex;
	output reg [6:0] segment;

		always @(*) begin
			/* Case statement implements a logic truth table using gates + OPENSUSI signage */
			case(hex)
				//                             7654321
				5'b 00000: segment = 7'b 1000000; // 0
				5'b 00001: segment = 7'b 1111001; // 1
				5'b 00010: segment = 7'b 0100100; // 2
				5'b 00011: segment = 7'b 0110000; // 3
				5'b 00100: segment = 7'b 0011001; // 4
				5'b 00101: segment = 7'b 0010010; // 5
				5'b 00110: segment = 7'b 0000010; // 6
				5'b 00111: segment = 7'b 1111000; // 7
				5'b 01000: segment = 7'b 0000000; // 8
				5'b 01001: segment = 7'b 0011000; // 9
				5'b 01010: segment = 7'b 0001000; // A
				5'b 01011: segment = 7'b 0000011; // b
				5'b 01100: segment = 7'b 0100111; // c
				5'b 01101: segment = 7'b 0100001; // d
				5'b 01110: segment = 7'b 0000110; // E
				5'b 01111: segment = 7'b 0001110; // F
				//
				5'b 10000: segment = 7'b 0111110; // -
				5'b 10001: segment = 7'b 1000000; // O
				5'b 10010: segment = 7'b 0001100; // P
				5'b 10011: segment = 7'b 0000110; // E
				5'b 10100: segment = 7'b 0001000; // N
				5'b 10101: segment = 7'b 0010010; // S
				5'b 10110: segment = 7'b 0000001; // U
				5'b 10111: segment = 7'b 0010010; // S
				5'b 11000: segment = 7'b 1111001; // I
				5'b 11001: segment = 7'b 0111111; // -
				5'b 11010: segment = 7'b 0001000; // A
				5'b 11011: segment = 7'b 1111001; // I
				5'b 11100: segment = 7'b 0010010; // S
				5'b 11101: segment = 7'b 0100011; // o
				5'b 11110: segment = 7'b 1001111; // l
				5'b 11111: segment = 7'b 0111111; // -
			endcase
		end