iic Verilog代码

这是一个简单的I2C Master模块的Verilog代码，用于与I2C设备进行通信。

module i2c_master(
    input clk,
    input rst,
    input start,
    input stop,
    input [7:0] data_in,
    output reg [7:0] data_out,
    output reg ack,
    output reg busy,
    output reg done
);

parameter IDLE = 0;
parameter SEND_ADDR = 1;
parameter SEND_DATA = 2;
parameter READ_DATA = 3;

reg [2:0] state;
reg [7:0] addr;
reg [7:0] data;
reg [3:0] bit_counter;
reg [2:0] byte_counter;
reg [1:0] cycle_counter;
reg scl;

assign busy = (state != IDLE) || (cycle_counter > 1);

always @(posedge clk or posedge rst) begin
    if (rst) begin
        state <= IDLE;
        bit_counter <= 0;
        byte_counter <= 0;
        cycle_counter <= 0;
        scl <= 1;
        ack <= 0;
        data_out <= 0;
        done <= 0;
    end else begin
        case (state)
            IDLE: begin
                if (start) begin
                    state <= SEND_ADDR;
                    addr <= data_in;
                    bit_counter <= 0;
                    byte_counter <= 0;
                    cycle_counter <= 0;
                end
            end
            SEND_ADDR: begin
                if (cycle_counter == 0) begin
                    scl <= 0;
                    cycle_counter <= cycle_counter + 1;
                end else if (cycle_counter == 1) begin
                    data_out <= (addr >> 7) & 1;
                    cycle_counter <= cycle_counter + 1;
                end else if (cycle_counter == 2) begin
                    scl <= 1;
                    cycle_counter <= cycle_counter + 1;
                end else if (cycle_counter == 3) begin
                    ack <= ~data_in;
                    if (ack) begin
                        if (addr & 1) begin
                            state <= READ_DATA;
                        end else begin
                            state <= SEND_DATA;
                            data <= data_in;
                        end
                    end else begin
                        state <= IDLE;
                    end
                    cycle_counter <= 0;
                end
            end
            SEND_DATA: begin
                if (cycle_counter == 0) begin
                    scl <= 0;
                    cycle_counter <= cycle_counter + 1;
                end else if (cycle_counter == 1) begin
                    data_out <= (data >> (7 - bit_counter)) & 1;
                    cycle_counter <= cycle_counter + 1;
                end else if (cycle_counter == 2) begin
                    scl <= 1;
                    cycle_counter <= cycle_counter + 1;
                end else if (cycle_counter == 3) begin
                    ack <= ~data_in;
                    if (ack) begin
                        if (bit_counter == 7) begin
                            byte_counter <= byte_counter + 1;
                            if (byte_counter == 2) begin
                                state <= IDLE;
                                done <= 1;
                            end else begin
                                state <= SEND_ADDR;
                                addr <= addr + 1;
                                bit_counter <= 0;
                            end
                        end else begin
                            bit_counter <= bit_counter + 1;
                        end
                    end else begin
                        state <= IDLE;
                    end
                    cycle_counter <= 0;
                end
            end
            READ_DATA: begin
                if (cycle_counter == 0) begin
                    scl <= 0;
                    cycle_counter <= cycle_counter + 1;
                end else if (cycle_counter == 1) begin
                    data_out <= 1;
                    cycle_counter <= cycle_counter + 1;
                end else if (cycle_counter == 2) begin
                    scl <= 1;
                    cycle_counter <= cycle_counter + 1;
                end else if (cycle_counter == 3) begin
                    data <= (data << 1) | data_in;
                    bit_counter <= bit_counter + 1;
                    if (bit_counter == 8) begin
                        bit_counter <= 0;
                        byte_counter <= byte_counter + 1;
                        if (byte_counter == 2) begin
                            state <= IDLE;
                            done <= 1;
                        end else begin
                            scl <= 0;
                            cycle_counter <= 0;
                        end
                    end else begin
                        scl <= 0;
                        cycle_counter <= 0;
                    end
                end
            end
        endcase
    end
end

endmodule

请注意，此代码仅用于学习和参考，可能需要根据您的具体需求进行修改。