设计一个uart项目，包括接收模块和发送模块，其中接收模块和发送模块中存在FIFO模块和状态机

以下是一个包括接收模块和发送模块的UART项目，其中接收模块和发送模块都有FIFO模块和状态机：

接收模块：

module uart_rx (
  input clk,
  input rst,
  input rx,
  output reg [7:0] data_out,
  output reg rx_done,
  output reg [3:0] err
);

  parameter CLK_FREQ = 50000000;
  parameter BAUD_RATE = 9600;

  localparam IDLE = 2'b00;
  localparam START = 2'b01;
  localparam DATA = 2'b10;
  localparam STOP = 2'b11;

  reg [7:0] fifo [0:15];
  reg [3:0] wr_ptr = 0;
  reg [3:0] rd_ptr = 0;
  wire [3:0] count = wr_ptr - rd_ptr;

  reg [1:0] state = IDLE;
  reg [3:0] bit_cnt = 0;
  reg [7:0] data = 0;
  reg rx_busy = 0;
  reg [3:0] rx_err = 0;

  // calculate the baud rate divisor
  reg [15:0] divisor = CLK_FREQ / BAUD_RATE;

  always @ (posedge clk or posedge rst) begin
    if (rst) begin
      wr_ptr <= 0;
      rd_ptr <= 0;
      state <= IDLE;
      bit_cnt <= 0;
      data <= 0;
      rx_done <= 0;
      rx_busy <= 0;
      rx_err <= 0;
      err <= 0;
      data_out <= 0;
    end else begin
      // check for errors
      if (rx == 0 && state != START && state != STOP && rx_busy == 0) begin
        rx_err <= rx_err + 1;
        err <= 1;
      end

      // receive data
      case (state)
        IDLE: begin
          if (rx == 0) begin
            state <= START;
            bit_cnt <= 0;
            data <= 0;
            rx_busy <= 1;
          end
        end
        START: begin
          if (bit_cnt == 0) begin
            if (rx == 1) begin
              state <= IDLE;
              rx_busy <= 0;
              rx_err <= 0;
              err <= 0;
            end else begin
              bit_cnt <= bit_cnt + 1;
            end
          end else if (bit_cnt > 0 && bit_cnt < 9) begin
            data[bit_cnt - 1] <= rx;
            bit_cnt <= bit_cnt + 1;
          end else if (bit_cnt == 9) begin
            if (rx == 1) begin
              state <= STOP;
              bit_cnt <= 0;
            end else begin
              rx_err <= rx_err + 1;
              state <= IDLE;
              rx_busy <= 0;
              err <= 1;
            end
          end
        end
        DATA: begin
          if (bit_cnt < 8) begin
            data[bit_cnt] <= rx;
            bit_cnt <= bit_cnt + 1;
          end else if (bit_cnt == 8) begin
            if (rx == 1) begin
              state <= STOP;
              bit_cnt <= 0;
            end else begin
              rx_err <= rx_err + 1;
              state <= IDLE;
              rx_busy <= 0;
              err <= 1;
            end
          end
        end
        STOP: begin
          if (rx == 1) begin
            fifo[wr_ptr] <= data;
            wr_ptr <= wr_ptr + 1;
            rx_done <= 1;
          end else begin
            rx_err <= rx_err + 1;
            state <= IDLE;
            rx_busy <= 0;
            err <= 1;
          end
        end
      endcase
    end
  end

  assign data_out = fifo[rd_ptr];
  assign count = wr_ptr - rd_ptr;
  assign rd_ptr = (rx_done) ? rd_ptr + 1 : rd_ptr;

endmodule

该接收模块包含一个状态机，用于解析接收到的数据。当探测到起始位时，状态机将进入“START”状态，并根据数据位的数量接收数据。在数据位之后，状态机将检查停止位是否正确，并将数据存储在FIFO中。如果发现错误，状态机将返回“IDLE”状态并丢弃数据。该接收模块还包括一个计数器，用于跟踪FIFO中的数据量，并具有一个输出信号，用于指示FIFO是否为空或已满。

发送模块：

module uart_tx (
  input clk,
  input rst,
  output reg tx,
  input [7:0] data_in,
  input wr_en,
  input rd_en,
  output reg full,
  output reg empty
);

  parameter CLK_FREQ = 50000000;
  parameter BAUD_RATE = 9600;

  localparam IDLE = 2'b00;
  localparam START = 2'b01;
  localparam DATA = 2'b10;
  localparam STOP = 2'b11;

  reg [7:0] fifo [0:15];
  reg [3:0] wr_ptr = 0;
  reg [3:0] rd_ptr = 0;
  wire [3:0] count = wr_ptr - rd_ptr;

  reg [1:0] state = IDLE;
  reg [3:0] bit_cnt = 0;
  reg [7:0] data_out = 0;
  reg tx_busy = 0;

  // calculate the baud rate divisor
  reg [15:0] divisor = CLK_FREQ / BAUD_RATE;

  always @ (posedge clk or posedge rst) begin
    if (rst) begin
      wr_ptr <= 0;
      rd_ptr <= 0;
      state <= IDLE;
      bit_cnt <= 0;
      data_out <= 0;
      tx <= 1;
      tx_busy <= 0;
      full <= 0;
      empty <= 1;
    end else begin
      // check if there is data in the FIFO to transmit
      if (tx_busy == 0 && count > 0) begin
        data_out <= fifo[rd_ptr];
        rd_ptr <= rd_ptr + 1;
        tx_busy <= 1;
      end

      // transmit data
      case (state)
        IDLE: begin
          if (tx_busy == 1) begin
            state <= START;
            bit_cnt <= 0;
            tx <= 0;
          end
        end
        START: begin
          if (bit_cnt == 0) begin
            tx <= 0;
            bit_cnt <= bit_cnt + 1;
          end else if (bit_cnt < 9) begin
            tx <= data_out[bit_cnt - 1];
            bit_cnt <= bit_cnt + 1;
          end else if (bit_cnt == 9) begin
            tx <= 1;
            bit_cnt <= bit_cnt + 1;
          end else if (bit_cnt == 10) begin
            tx_busy <= 0;
            bit_cnt <= 0;
            state <= IDLE;
          end
        end
      endcase

      // write data to FIFO
      if (wr_en && count < 16) begin
        fifo[wr_ptr] <= data_in;
        wr_ptr <= wr_ptr + 1;
        empty <= 0;
      end

      // update status signals
      full <= (count == 16);
    end
  end

endmodule

该发送模块也包含一个状态机，用于发送FIFO中的数据。当FIFO中有数据时，状态机将进入“START”状态，并在每个位时间发送数据。当数据被完全发送后，状态机将返回“IDLE”状态。该发送模块还包括一个计数器，用于跟踪FIFO中的数据量，并具有输出信号，用于指示FIFO是否为空或已满。