`timescale 1ns / 1ps module liushuideng( input clk, input rst_n, output reg [7:0] led ); reg [25:0] cnt; always @(posedge clk or negedge rst_n) if(!rst_n) cnt<=26'd0; else if(cnt==26'd25000000-1'd1) cnt<=26'd0; else cnt<=cnt+1'd1 ; reg clk_1hz; always @(posedge clk or negedge rst_n ) if (!rst_n) clk_1hz<=1'd0; else if(cnt==26'd25000000-1'd1) clk_1hz<=~clk_1hz; else clk_1hz<= clk_1hz; reg [7:0] count; always @(posedge clk_1hz or negedge rst_n ) if (!rst_n) count <=8'd0; else if (count==8'd23) count<=8'd0; else count<=count+1'd1; always @(posedge clk_1hz or negedge rst_n) if (!rst_n) led<=8'b1000_0001; else if (count == 8'd0) led<=8'b1000_0001; else if (count>=8'd0 && count<=8'd3) led<={led[4],led[7:5],led[2:0],led[3]}; else if (count == 8'd4) led<=8'b0001_1000; else if (count>=8'd4 && count<=8'd7) led<={led[6:4],led[7],led[0],led[3:1]}; else if (count == 8'd8) led<=8'b1000_0000; else if (count>=8'd8 && count <=8'd15) led<={led[0],led[7:1]}; else if (count>=8'd16 && count <=8'd23) led<={led[6:0],led[7]}; else led<=led; endmodule测试激励文件怎么写

以下是一个简单的 Verilog 激励文件示例，用于测试 liushuideng 模块：

`timescale 1ns / 1ps

module liushuideng_tb();

    reg clk;
    reg rst_n;
    wire [7:0] led;

    liushuideng dut(.clk(clk), .rst_n(rst_n), .led(led));

    initial begin
        clk = 0;
        forever #5 clk = ~clk;
    end

    initial begin
        rst_n = 0;
        #100 rst_n = 1;
        #5000 $finish;
    end

endmodule

该激励文件定义了一个 liushuideng_tb 模块，该模块实例化了 liushuideng 模块，并为其连接了时钟信号 clk、复位信号 rst_n 和 LED 灯输出 led。在 initial 块中，时钟信号 clk 被定义为一个周期为 10 ns 的方波，并通过 forever 循环不断翻转。复位信号 rst_n 在初始时被设为 0，经过 100 ns 后被设为 1，模拟了一个下降沿复位的场景。最后，通过 #5000 延时使仿真停止，并使用 $finish 命令结束仿真。你可以根据需要修改激励文件的内容，以适应你的测试需求。

相关问题

代码为：module dut(clk,rst_n,rxd,rx_dv,txd,tx_en); input clk; input rst_n; input [7:0]rxd; input rx_dv; output [7:0]txd; output tx_en; reg[7:0] txd; reg tx_en; always @(posedge clk) begin if (!rst_n) begin txd <= 8'b0; tx_en <= 1'b0; end else begin txd <= rxd; tx_en <= rx_dv; end end endmodule

好的，基于您提供的代码，我可以为您编写UVM验证代码。下面是可能的实现方式：

`timescale 1ns / 1ns

module dut(clk,rst_n,rxd,rx_dv,txd,tx_en);
  input clk;
  input rst_n;
  input [7:0]rxd;
  input rx_dv;
  output [7:0]txd;
  output tx_en;

  reg[7:0] txd;
  reg tx_en;

  always @(posedge clk) begin
    if (!rst_n) begin
      txd <= 8'b0;
      tx_en <= 1'b0;
    end
    else begin
      txd <= rxd;
      tx_en <= rx_dv;
    end
  end
endmodule

module dut_tb;

  // Declare the interface signals
  logic clk;
  logic rst_n;
  logic [7:0]rxd;
  logic rx_dv;
  logic [7:0]txd;
  logic tx_en;

  // Instantiate the DUT
  dut dut_inst(
    .clk(clk),
    .rst_n(rst_n),
    .rxd(rxd),
    .rx_dv(rx_dv),
    .txd(txd),
    .tx_en(tx_en)
  );

  // Declare the UVM environment
  my_env env;

  // Declare the UVM agent
  my_agent agent;

  // Declare the UVM virtual interface
  my_vif vif;

  // Instantiate the UVM environment and agent
  initial begin
    env = my_env::type_id::create("env");
    agent = my_agent::type_id::create("agent", env);
  end

  // Instantiate the UVM virtual interface and connect it to the DUT
  initial begin
    vif = my_vif::type_id::create("vif");
    vif.clk = clk;
    vif.rst_n = rst_n;
    vif.rxd = rxd;
    vif.rx_dv = rx_dv;
    vif.txd = txd;
    vif.tx_en = tx_en;
  end

  // Connect the agent to the virtual interface
  initial begin
    agent.vif = vif;
  end

  // Start the test
  initial begin
    run_test();
  end

endmodule

class my_env extends uvm_env;
  // Declare the components of the environment
  my_agent agent;

  // Override the build_phase method to create the agent
  function void build_phase(uvm_phase phase);
    super.build_phase(phase);
    agent = my_agent::type_id::create("agent", this);
  endfunction

  // Override the connect_phase method to connect the agent to the virtual interface
  function void connect_phase(uvm_phase phase);
    super.connect_phase(phase);
    agent.vif = vif;
  endfunction

endclass

class my_agent extends uvm_agent;
  // Declare the components of the agent
  my_driver driver;
  my_monitor monitor;

  // Declare the virtual interface
  my_vif vif;

  // Override the build_phase method to create the driver and monitor
  function void build_phase(uvm_phase phase);
    super.build_phase(phase);
    driver = my_driver::type_id::create("driver", this);
    monitor = my_monitor::type_id::create("monitor", this);
  endfunction

  // Override the connect_phase method to connect the driver and monitor to the virtual interface
  function void connect_phase(uvm_phase phase);
    super.connect_phase(phase);
    driver.vif = vif;
    monitor.vif = vif;
  endfunction

endclass

class my_driver extends uvm_driver #(my_pkt);
  // Declare the virtual interface
  my_vif vif;

  // Override the run_phase method to send packets to the DUT
  task run_phase(uvm_phase phase);
    super.run_phase(phase);
    // Send packets to the DUT
  endtask

endclass

class my_monitor extends uvm_monitor #(my_pkt);
  // Declare the virtual interface
  my_vif vif;

  // Override the run_phase method to monitor packets from the DUT
  task run_phase(uvm_phase phase);
    super.run_phase(phase);
    // Monitor packets from the DUT
  endtask

endclass

class my_pkt extends uvm_sequence_item;
  // Declare the properties of the packet
  // ...

  // Override the do_print method to print the packet
  function void do_print(uvm_printer printer);
    super.do_print(printer);
    // Print the packet
  endfunction

endclass

class my_vif extends uvm_vif;
  // Declare the signals of the virtual interface
  logic clk;
  logic rst_n;
  logic [7:0]rxd;
  logic rx_dv;
  logic [7:0]txd;
  logic tx_en;

endclass

这是一个简单的UVM测试框架，其中包含一个仿真环境、一个代理、一个驱动程序、一个监视器、一个数据包和一个虚拟接口。这个框架可以用于验证您提供的DUT模块。您需要根据实际情况进行修改和扩展。

`timescale 1ns / 1ps module pc_main( input clk, input rst, input wire [31:0] npc, output reg [31:0] pc ); reg state; always@(posedge clk or negedge rst)begin if(~rst) state <= 0; else state <= 1; end always@(posedge clk or negedge rst)begin if(~rst) pc <= 0; else pc <= state?npc:0; end endmodule

这是一个Verilog HDL语言编写的程序计数器模块(pc_main)。下面是对各个部分的解释：

- clk：输入时钟端口，用于同步程序计数器的计数；
- rst：输入复位端口，当高电平时，将程序计数器清零；
- npc：输入端口，表示下一条指令的地址；
- pc：输出端口，表示当前指令的地址；

其中，`timescale 1ns / 1ps`表示时间单位，1ns为时间单位，1ps为时间精度，即1ns内的时钟周期数。

在模块中定义了一个状态变量state，表示程序计数器的工作状态，当rst为高电平时，将state变量清零。

always@(posedge clk or negedge rst)begin...end语句表示在时钟上升沿或者复位信号下降沿时，根据rst的值，将程序计数器pc赋值。当rst为高电平时，将pc清零；当rst为低电平时，根据state的值，将pc赋值为npc或者0。