iic verilog

IIC (Inter-Integrated Circuit) is a serial communication protocol used to connect low-speed peripherals with microcontrollers or other devices. Verilog is a hardware description language used to design digital circuits.

To implement IIC protocol in Verilog, you need to define the IIC module with input and output ports for data and clock lines. The module should include a state machine that controls the start, stop, and data transfer operations of the IIC bus. Here is an example code for IIC master module in Verilog:

module iic_master(
    input wire clk,
    input wire rst,
    input wire [7:0] addr,
    input wire [7:0] data_in,
    input wire wr_en,
    output reg [7:0] data_out,
    output reg sda,
    output reg scl
);

reg [7:0] data_buf;
reg [3:0] state;

parameter IDLE = 4'b0000;
parameter START = 4'b0001;
parameter ADDR = 4'b0010;
parameter DATA = 4'b0100;
parameter STOP = 4'b1000;

always @(posedge clk, posedge rst)
begin
    if (rst) begin
        state <= IDLE;
        sda <= 1'b1;
        scl <= 1'b1;
    end
    else begin
        case (state)
            IDLE: begin
                if (wr_en) begin
                    data_buf <= data_in;
                    state <= START;
                end
                else begin
                    data_out <= 8'h00;
                    state <= IDLE;
                end
            end
            START: begin
                sda <= 1'b0;
                scl <= 1'b0;
                state <= ADDR;
            end
            ADDR: begin
                for (i=0; i<8; i=i+1) begin
                    sda <= addr[7-i];
                    scl <= 1'b1;
                    scl <= 1'b0;
                end
                sda <= 1'b1;
                scl <= 1'b1;
                state <= DATA;
            end
            DATA: begin
                for (i=0; i<8; i=i+1) begin
                    sda <= data_buf[7-i];
                    scl <= 1'b1;
                    scl <= 1'b0;
                end
                sda <= 1'b1;
                scl <= 1'b1;
                state <= STOP;
            end
            STOP: begin
                sda <= 1'b0;
                scl <= 1'b1;
                sda <= 1'b1;
                scl <= 1'b0;
                state <= IDLE;
                data_out <= data_in;
            end
        endcase
    end
end

endmodule

This Verilog code defines an IIC master module that takes 8-bit address and data inputs and performs write operations to the IIC bus. The module includes a state machine that controls the start, address, data, and stop operations of the IIC bus. The code can be modified for different IIC operations and for slave mode operation.