一个完整的sdi编解码的verilog实现和逐行注释

SDI（Serial Digital Interface）是一种数字视频传输标准，可用于将高清视频和音频信号从一个设备传输到另一个设备。本文将提供一个简单的SDI编解码器的Verilog实现，并进行逐行注释。

【注】本文不涉及SDI标准的详细介绍，如需了解更多请参考相关文献。

## SDI编码器

### 模块接口

module sdi_encoder(
    input clk,           // 时钟信号
    input rst,           // 复位信号
    input [7:0] data_in, // 输入数据
    output sdi_out       // SDI输出
);

### 模块实现

module sdi_encoder(
    input clk,
    input rst,
    input [7:0] data_in,
    output sdi_out
);
    reg [9:0] cnt;       // 计数器
    reg [7:0] data_out;  // 输出数据
    reg [3:0] state;     // 状态机状态

    parameter IDLE = 0,  // 空闲状态
              F1   = 1,  // 字节1状态
              F2   = 2,  // 字节2状态
              F3   = 3,  // 字节3状态
              F4   = 4,  // 字节4状态
              F5   = 5,  // 字节5状态
              F6   = 6,  // 字节6状态
              F7   = 7,  // 字节7状态
              F8   = 8,  // 字节8状态
              F9   = 9,  // 字节9状态
              F10  = 10; // 字节10状态

    always @(posedge clk or posedge rst) begin
        if (rst) begin  // 复位状态
            cnt <= 0;
            data_out <= 0;
            state <= IDLE;
        end else begin
            case (state)  // 状态机
                IDLE: begin
                    cnt <= 0;
                    data_out <= 0;
                    state <= F1;
                end
                F1: begin
                    cnt <= cnt + 1;
                    data_out <= data_in;
                    state <= F2;
                end
                F2: begin
                    cnt <= cnt + 1;
                    data_out <= data_out ^ 8'hFF;
                    state <= F3;
                end
                F3: begin
                    cnt <= cnt + 1;
                    data_out <= (cnt == 8'h1F) ? 8'h01 : 8'h03;
                    state <= F4;
                end
                F4: begin
                    cnt <= cnt + 1;
                    data_out <= (cnt == 8'h1F) ? 8'h80 : 8'h10;
                    state <= F5;
                end
                F5: begin
                    cnt <= cnt + 1;
                    data_out <= (cnt == 8'h1F) ? 8'h01 : 8'h03;
                    state <= F6;
                end
                F6: begin
                    cnt <= cnt + 1;
                    data_out <= (cnt == 8'h1F) ? 8'h80 : 8'h20;
                    state <= F7;
                end
                F7: begin
                    cnt <= cnt + 1;
                    data_out <= (cnt == 8'h1F) ? 8'h01 : 8'h03;
                    state <= F8;
                end
                F8: begin
                    cnt <= cnt + 1;
                    data_out <= (cnt == 8'h1F) ? 8'h80 : 8'h40;
                    state <= F9;
                end
                F9: begin
                    cnt <= cnt + 1;
                    data_out <= (cnt == 8'h1F) ? 8'h01 : 8'h03;
                    state <= F10;
                end
                F10: begin
                    cnt <= 0;
                    data_out <= 0;
                    state <= IDLE;
                end
            endcase
        end
    end

    assign sdi_out = data_out;  // SDI输出
endmodule

## SDI解码器

### 模块接口

module sdi_decoder(
    input clk,           // 时钟信号
    input rst,           // 复位信号
    input sdi_in,        // SDI输入
    output reg [7:0] data_out // 输出数据
);

### 模块实现

module sdi_decoder(
    input clk,
    input rst,
    input sdi_in,
    output reg [7:0] data_out
);
    reg [3:0] state;     // 状态机状态
    reg [9:0] cnt;       // 计数器
    reg [7:0] data_in;   // 输入数据

    parameter IDLE = 0,  // 空闲状态
              F1   = 1,  // 字节1状态
              F2   = 2,  // 字节2状态
              F3   = 3,  // 字节3状态
              F4   = 4,  // 字节4状态
              F5   = 5,  // 字节5状态
              F6   = 6,  // 字节6状态
              F7   = 7,  // 字节7状态
              F8   = 8,  // 字节8状态
              F9   = 9,  // 字节9状态
              F10  = 10; // 字节10状态

    always @(posedge clk or posedge rst) begin
        if (rst) begin  // 复位状态
            state <= IDLE;
            cnt <= 0;
            data_in <= 0;
            data_out <= 0;
        end else begin
            case (state)  // 状态机
                IDLE: begin
                    if (sdi_in == 8'hFF) begin
                        state <= F1;
                        cnt <= 0;
                        data_in <= 0;
                    end
                end
                F1: begin
                    cnt <= cnt + 1;
                    data_in <= sdi_in;
                    state <= F2;
                end
                F2: begin
                    cnt <= cnt + 1;
                    data_in <= data_in ^ 8'hFF;
                    state <= F3;
                end
                F3: begin
                    cnt <= cnt + 1;
                    if (cnt == 8'h1F) begin
                        if (data_in == 8'h01) begin
                            state <= F4;
                            cnt <= 0;
                        end else if (data_in == 8'h03) begin
                            state <= F5;
                            cnt <= 0;
                        end
                    end
                end
                F4: begin
                    cnt <= cnt + 1;
                    if (cnt == 8'h1F) begin
                        if (data_in == 8'h80) begin
                            state <= F5;
                            cnt <= 0;
                        end
                    end
                end
                F5: begin
                    cnt <= cnt + 1;
                    if (cnt == 8'h1F) begin
                        if (data_in == 8'h01) begin
                            state <= F6;
                            cnt <= 0;
                        end else if (data_in == 8'h03) begin
                            state <= F7;
                            cnt <= 0;
                        end
                    end
                end
                F6: begin
                    cnt <= cnt + 1;
                    if (cnt == 8'h1F) begin
                        if (data_in == 8'h80) begin
                            state <= F7;
                            cnt <= 0;
                        end
                    end
                end
                F7: begin
                    cnt <= cnt + 1;
                    if (cnt == 8'h1F) begin
                        if (data_in == 8'h01) begin
                            state <= F8;
                            cnt <= 0;
                        end else if (data_in == 8'h03) begin
                            state <= F9;
                            cnt <= 0;
                        end
                    end
                end
                F8: begin
                    cnt <= cnt + 1;
                    if (cnt == 8'h1F) begin
                        if (data_in == 8'h80) begin
                            state <= F9;
                            cnt <= 0;
                        end
                    end
                end
                F9: begin
                    cnt <= cnt + 1;
                    if (cnt == 8'h1F) begin
                        if (data_in == 8'h01) begin
                            state <= F10;
                            cnt <= 0;
                            data_out <= data_out + 1;
                        end else if (data_in == 8'h03) begin
                            state <= F10;
                            cnt <= 0;
                            data_out <= data_out - 1;
                        end
                    end
                end
                F10: begin
                    state <= IDLE;
                    cnt <= 0;
                end
            endcase
        end
    end
endmodule

以上就是一个简单的SDI编解码器的Verilog实现及逐行注释。需要注意的是，这只是一个基础的实现，实际应用中还需要考虑更多的细节和异常处理。