用verilog写一段串口通信

以下是使用Verilog实现串口通信的示例代码：

module uart_tx_rx ( input clk, //时钟信号 input rst, //复位信号 input tx_en, //发送使能信号 input [7:0] tx_data, //发送数据 input rx_en, //接收使能信号 output reg [7:0] rx_data, //接收数据 output reg rx_done //接收完成信号 );

//定义计数器 reg [3:0] count;

//定义发送寄存器 reg [7:0] tx_reg;

//定义接收寄存器 reg [7:0] rx_reg;

//定义发送状态机状态 reg [1:0] tx_state;

//定义接收状态机状态 reg [2:0] rx_state;

//定义波特率计数器 localparam BAUD_RATE = 9600; reg [15:0] baud_count = 0;

//定义发送状态机状态 parameter IDLE = 2'b00; parameter START = 2'b01; parameter DATA = 2'b10; parameter STOP = 2'b11;

//定义接收状态机状态 parameter RX_IDLE = 3'b000; parameter RX_START = 3'b001; parameter RX_DATA = 3'b010; parameter RX_PARITY = 3'b011; parameter RX_STOP = 3'b100;

//发送状态机 always @ (posedge clk or negedge rst) begin if (rst == 0) begin tx_state <= IDLE; tx_reg <= 0; count <= 0; end else begin case (tx_state) IDLE: begin count <= 0; if (tx_en) begin tx_reg <= tx_data; tx_state <= START; end end START: begin count <= count + 1; if (count >= 3) begin count <= 0; tx_state <= DATA; end end DATA: begin count <= count + 1; if (count >= 8) begin count <= 0; tx_state <= STOP; end end STOP: begin count <= count + 1; if (count >= 3) begin count <= 0; tx_state <= IDLE; end end endcase end end

//接收状态机 always @ (posedge clk or negedge rst) begin if (rst == 0) begin rx_state <= RX_IDLE; rx_reg <= 0; count <= 0; baud_count <= 0; end else begin case (rx_state) RX_IDLE: begin count <= 0; baud_count <= 0; if (rx_en) begin rx_state <= RX_START; end end RX_START: begin count <= count + 1; if (count >= 3) begin count <= 0; baud_count <= 0; rx_state <= RX_DATA; end end RX_DATA: begin count <= count + 1; baud_count <= baud_count + 1; if (baud_count == BAUD_RATE) begin baud_count <= 0; rx_reg <= {rx_reg[6:0], rx_en}; end if (count >= 8) begin count <= 0; rx_state <= RX_PARITY; end end RX_PARITY: begin count <= count + 1; if (count >= 1) begin count <= 0; rx_state <= RX_STOP; end end RX_STOP: begin count <= count + 1; if (count >= 3) begin count <= 0; rx_done <= 1; rx_data <= rx_reg; rx_state <= RX_IDLE; end end endcase end end

endmodule

上述代码实现了一个简单的串口通信模块，其中包含了发送和接收状态机。该模块可以通过调整BAUD_RATE参数来实现不同的波特率。同时，该模块也可以通过调整tx_en和rx_en信号来控制发送和接收的启用状态。