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 Sebastien Paradis
 * SPDX-License-Identifier: Apache-2.0
 */

`default_nettype none

// Top Module
module tt_um_sebastienparadis_hamming_top (
    input  wire [7:0] ui_in,    // Dedicated inputs
    output wire [7:0] uo_out,   // Dedicated outputs
    input  wire [7:0] uio_in,   // IOs: Input path
    output wire [7:0] uio_out,  // IOs: Output path
    output wire [7:0] uio_oe,   // IOs: Enable path (active high: 0=input, 1=output)
    input  wire       ena,      // always 1 when the design is powered, so you can ignore it
    input  wire       clk,      // clock
    input  wire       rst_n     // reset_n - low to reset
);

    // Mode selection
    wire mode = ui_in[7];            // MSB of ui_in as mode selector (0 => Encode, 1 => Decode)

    // Input signals
    wire [3:0] data_in = ui_in[3:0]; // 4-bit data for encoding mode
    wire [6:0] code_in = ui_in[6:0]; // 7-bit code for decoding mode

    // Internal signals for encoded and decoded outputs
    wire [6:0] encoded_code;
    wire [6:0] decoded_data;

    // Instantiating Hamming Controller
    hamming_controller hamming_inst (
        .data(data_in),
        .code(code_in),
        .mode(mode),
        .encoded_code(encoded_code),
        .decoded_data(decoded_data)
    );

    // Output assignments based on mode
    assign uo_out = (mode == 0) ? {1'b0, encoded_code} : {1'b0, decoded_data};

    assign uio_out = 8'b0;                 // Unused I/O output
    assign uio_oe  = 8'b0;                 // Unused I/O enable

    // Prevent warnings by listing unused inputs
    wire _unused = &{ena, clk, rst_n, uio_in, 1'b0};
endmodule

// Hamming Controller
module hamming_controller (
    input wire [3:0] data,           // 4-bit input data for encoding
    input wire [6:0] code,           // 7-bit input code for decoding
    input wire mode,                 // Mode selector: 0 for encode, 1 for decode
    output wire [6:0] encoded_code,  // Encoded output code
    output wire [6:0] decoded_data    // Decoded output data
);
// >>> Module Implementation Begin

// <<< Module Implementation End
endmodule



/*
 * Copyright (c) 2024 Sebastien Paradis
 * SPDX-License-Identifier: Apache-2.0
 */

// Hamming Decoder
module hamming_decoder (
    input wire [6:0] code,            // 7-bit codeword input
    output wire [6:0] data_out       // 7-bit corrected data output
);

    wire [6:0] corrected_code; // 7-bit corrected codeword
    wire [2:0] syndrome; // Syndrome Bits

    assign syndrome[0] = code[6] ^ code[4] ^ code[2] ^ code[0]; // S0
    assign syndrome[1] = code[5] ^ code[4] ^ code[1] ^ code[0]; // S1
    assign syndrome[2] = code[3] ^ code[2] ^ code[1] ^ code[0]; // S2

    // Bit Correction
    assign corrected_code = (syndrome != 3'b000) ? (code ^ (1 << (7 - syndrome))) : code;

    assign data_out = corrected_code;
endmodule


/*
 * Copyright (c) 2024 Sebastien Paradis
 * SPDX-License-Identifier: Apache-2.0
 */


// Hamming Encoder
module hamming_encoder (
    input wire [3:0] data,   // 4 data bits
    output wire [6:0] code   // 7-bit codeword
);

    wire p1, p2, p3;

    //data: d1 d2 d3 d4
    //parity: p1 p2 p3

    assign p1 = data[3] ^ data[2] ^ data[0]; // p1 is the parity bit for bits 1, 2, and 4
    assign p2 = data[3] ^ data[1] ^ data[0]; // p2 is the parity bit for bits 1, 3, and 4
    assign p3 = data[2] ^ data[1] ^ data[0]; // p3 is the parity bit for bits 2, 3, and 4

    assign code = {p1, p2, data[3], p3, data[2], data[1], data[0]}; // p1 p2 d1 p3 d2 d3 d4
endmodule

Reference solution:
rtl/generated.v: 
    // Internal signals
    wire [6:0] encoder_code;         // Codeword output from encoder
    wire [6:0] decoder_data;         // Data output from decoder

    // Instantiating Hamming Encoder
    hamming_encoder encoder (
        .data(data),
        .code(encoder_code)
    );

    // Instantiating Hamming Decoder
    hamming_decoder decoder (
        .code(code),
        .data_out(decoder_data)
    );

    // // Output based on mode
    assign encoded_code = (mode == 0) ? encoder_code : 7'b0; // Output encoded code only in encoding mode
    assign decoded_data = (mode == 1) ? decoder_data : 7'b0; // Output decoded data only in decoding mode