给一个带有FIFO模块的uart项目

以下是一个带有FIFO模块的UART项目的示例:

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

  parameter BAUD_RATE = 9600;
  parameter CLK_FREQ = 50000000;

  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 tx_busy = 0;
  reg [7:0] tx_data;
  reg [3:0] bit_cnt = 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;
      tx_busy <= 0;
      bit_cnt <= 0;
      data_out <= 0;
    end else begin
      // check if there is data in the FIFO to transmit
      if (tx_busy == 0 && count > 0) begin
        tx_data <= fifo[rd_ptr];
        rd_ptr <= rd_ptr + 1;
        tx_busy <= 1;
      end

      // transmit data
      if (tx_busy) begin
        if (bit_cnt == 0) begin
          tx <= 0;
          bit_cnt <= bit_cnt + 1;
        end else if (bit_cnt < 9) begin
          tx <= tx_data[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;
        end
      end

      // receive data
      if (rx == 0 && bit_cnt == 0) begin
        bit_cnt <= bit_cnt + 1;
      end else if (bit_cnt > 0 && bit_cnt < 9) begin
        data_in[bit_cnt - 1] <= rx;
        bit_cnt <= bit_cnt + 1;
      end else if (bit_cnt == 9) begin
        bit_cnt <= 0;
        if (wr_en && count < 16) begin
          fifo[wr_ptr] <= data_in;
          wr_ptr <= wr_ptr + 1;
        end
      end
    end
  end

  assign full = (count == 16);
  assign empty = (count == 0);
  assign data_out = fifo[rd_ptr];

  // set the initial state of the output
  initial begin
    tx <= 1;
  end

endmodule

该项目包含一个带有16字节FIFO缓存的UART模块，并支持读写控制信号。它还有一个计数器，用于跟踪FIFO中的数据量，并且有一个输出信号，用于指示FIFO是否为空或已满。在时钟的上升沿上，该模块将执行数据的传输和接收，并且在必要时更新FIFO指针。