用verilog写一个fpga内部i2c总线控制器

以下是一个简单的Verilog代码示例，用于实现FPGA内部的I2C总线控制器。

module i2c_controller
(
    input clk,              //时钟信号
    input rst,              //复位信号
    input scl,              //I2C时钟信号
    inout sda               //I2C数据信号
);

// 端口定义
// ...

// 控制状态定义
parameter IDLE_STATE = 2'b00;
parameter START_STATE = 2'b01;
parameter ADDR_STATE = 2'b10;
parameter DATA_STATE = 2'b11;

// 寄存器定义
reg [7:0] slave_address;
reg [7:0] data_out;
reg [7:0] data_in;
reg [7:0] data_cnt;
reg [1:0] state;
reg        rw;
reg        acknowledge;

// 状态机
always @(posedge clk or posedge rst) begin
    if (rst) begin
        state <= IDLE_STATE;
        data_cnt <= 0;
        acknowledge <= 0;
    end else begin
        case (state)
            IDLE_STATE: begin
                if (!scl && sda) begin
                    state <= START_STATE;
                end
            end
            START_STATE: begin
                sda <= 0;
                state <= ADDR_STATE;
            end
            ADDR_STATE: begin
                if (scl && !sda) begin
                    slave_address <= data_out;
                    acknowledge <= 1;
                    state <= DATA_STATE;
                end
            end
            DATA_STATE: begin
                if (scl && !sda) begin
                    if (data_cnt == 0) begin
                        rw <= sda;
                        acknowledge <= 1;
                        data_cnt <= 7;
                    end else begin
                        if (rw) begin
                            data_in[data_cnt] <= sda;
                        end else begin
                            sda <= data_out[data_cnt];
                        end
                        acknowledge <= 1;
                        data_cnt <= data_cnt - 1;
                    end
                    if (data_cnt == 0) begin
                        sda <= 1;
                        state <= IDLE_STATE;
                    end
                end
            end
        endcase
    end
end

// 数据输入输出
always @(posedge clk) begin
    if (state == DATA_STATE) begin
        if (!scl && !sda) begin
            if (rw) begin
                data_out <= 0;
            end else begin
                data_out <= data_in;
            end
        end
    end
end

endmodule

这段代码实现了一个基本的I2C总线控制器，包括状态机、寄存器和数据输入输出等。在具体应用中，需要根据实际情况进行配置和修改。