为什么我在 SV Testbench 模块驱动程序和监视器中通过槽设计后没有得到输出?

问题描述 投票:0回答:1

这里我附上了 sv 中的设计和测试平台环境代码: 这是设计模块

// Code your design here
// Code your design here
module router_1x3 (
    input wire clk,
    input wire rst,
    input wire [7:0] data_in,  // 8-bit data input
    input wire [1:0] sel,      // 2-bit select signal
    output reg [7:0] out0,     // Output channel 0
    output reg [7:0] out1,     // Output channel 1
    output reg [7:0] out2      // Output channel 2
);

    always @(posedge clk or posedge rst) begin
        if (rst) begin
            out0 <= 8'b0; // Reset output 0
            out1 <= 8'b0; // Reset output 1
            out2 <= 8'b0; // Reset output 2
        end else begin
            case (sel)
                2'b00: begin
                    out0 <= data_in;
                    out1 <= 8'b0;
                    out2 <= 8'b0;
                end
                2'b01: begin
                    out0 <= 8'b0;
                    out1 <= data_in;
                    out2 <= 8'b0;
                end
                2'b10: begin
                    out0 <= 8'b0;
                    out1 <= 8'b0;
                    out2 <= data_in;
                end
                default: begin
                    out0 <= 8'b0;
                    out1 <= 8'b0;
                    out2 <= 8'b0;
                end
            endcase
        end
    end

endmodule

接口.sv

interface intf();
    logic clk;
    logic rst;
    logic [7:0] data_in;
    logic [1:0] sel;
    logic [7:0] out0;
    logic [7:0] out1;
    logic [7:0] out2;
endinterface

交易.sv

class transaction;
  rand bit [7:0] data_in;
  rand bit [1:0] sel;
  bit [7:0] out0;
  bit [7:0] out1;
  bit [7:0] out2;
  
  constraint valid_sel {sel <= 2'b10;}
  
  function void display(string name);
    $display("---------- %s --------- %t", name, $time);
    $display("data_in=%h, sel=%h, out0=%h, out1=%h, out2=%h", 
             data_in, sel, out0, out1, out2);
  endfunction
endclass

生成器.sv

class generator;
  
    transaction tx;
    mailbox gen2drv;
  
    // Constructor
    function new(mailbox gen2drv);
        this.gen2drv = gen2drv;
    endfunction

    task main();
        tx = new();
      if (tx.randomize()) begin
        tx.display("generator");
        gen2drv.put(tx);
        
        end
    endtask
endclass

驱动程序.sv

class driver;
  transaction trans;
  virtual intf vif;
  
  mailbox gen2driv;
  
  function new(virtual intf vif, mailbox gen2driv);
    this.vif = vif;
    this.gen2driv = gen2driv;
  endfunction
  
  task main();
    
    repeat(1)
      begin
        
        gen2driv.get(trans);
        
        trans.display("Driver");
        
//         vif.data_in = trans.data_in;
//         vif.sel = trans.sel;
        
//         vif.out0 = trans.out0;
//      vif.out1 = trans.out1;
//         vif.out2 = trans.out2 ;
        
        vif.data_in <= trans.data_in;
        vif.sel <= trans.sel;
        
        vif.out0 <= trans.out0;
        vif.out1 <= trans.out1;
        vif.out2 <= trans.out2 ;
        
        
        
      end
  endtask
  
endclass

监视器.sv

class monitor;
  virtual intf vif;
  mailbox mon2sbc;
  transaction trans;
  function new(virtual intf vif, mailbox mon2sbc);
    this.vif = vif;
    this.mon2sbc = mon2sbc;
    
  endfunction
  
  task main();
    repeat(1)
      #3;
      begin
        
        trans = new();
        trans.data_in = vif.data_in;
        trans.sel = vif.sel;
        
//         trans.out0 = vif.out0;
//         trans.out1 = vif.out1;
//         trans.out2 = vif.out2;
        
         vif.out0 = trans.out0;
         vif.out1 = trans.out1;
         vif.out2 = trans.out2;
        
        
        mon2sbc.put(trans);
        #1
        trans.display("Monitor");
      end
  endtask
endclass

记分板.sv

class scoreboard;
   mailbox mon2sbc;
   transaction trans;
  function new(mailbox mon2sbc);
    this.mon2sbc = mon2sbc;
    
  endfunction
  
  task main();
    
    repeat(1)
      begin
        
        mon2sbc.get(trans);
        

        trans.display("Scoreboard");
        
          
      end
  endtask
   
endclass

环境.sv

`include "transaction.sv"
`include "generator.sv"
`include "driver.sv"
`include "scoreboard.sv"
`include "monitor.sv"

class environment;// it's complete environment of dut
                    // which is contain all component of testbench and connect tham  
  generator gen;    
  driver driv;
  monitor mon;
  scoreboard scb;
  
  mailbox m1;
  mailbox m2;
  
  virtual intf vif;
  
  function new(virtual intf vif);
    this.vif = vif;
    
    m1 = new();
    m2 = new();
    gen = new(m1);
    driv = new(vif,m1);
    mon = new(vif, m2);
    scb = new(m2);
    
  endfunction
  
  task test();
    fork
      gen.main();
      driv.main();
      mon.main();
      scb.main();
      
    join_none
  endtask
  
  task run;
    test();
    #100
    $finish;
  endtask
  
endclass

测试.sv

`include "environment.sv"

program test(intf i_intf);//this connect interface to testbech environment
  environment env;
  
  initial
  begin
    env = new(i_intf);
    env.run();
    
  end
endprogram

testbenchtop.sv

// Code your testbench here
// or browse Examples
`include "interface.sv"
`include "test.sv"

module tbench_top;
  intf router_vif();
  test t1(router_vif);
  
 router_1x3 dut (
        .clk(router_vif.clk),
        .rst(router_vif.rst),
        .data_in(router_vif.data_in),
        .sel(router_vif.sel),
        .out0(router_vif.out0),
        .out1(router_vif.out1),
        .out2(router_vif.out2)
    );

  
  // Clock generation
    initial begin
        router_vif.clk = 0;
        forever #5 router_vif.clk = ~router_vif.clk;
    end

    // Reset logic
    initial begin
        router_vif.rst = 1;
        #20;
        router_vif.rst = 0;
    end

  initial
    begin
      $dumpfile("dump.vcd");
      $dumpvars;
    end
  
endmodule
 

通过在 eda 中运行此代码(代码链接:https://edaplayground.com/x/F7jS)我得到以下输出

ERNEL: ASDB file was created in location /home/runner/dataset.asdb
# KERNEL: ---------- generator ---------                    0
# KERNEL: data_in=35, sel=2, out0=00, out1=00, out2=00
# KERNEL: ---------- Driver ---------                    0
# KERNEL: data_in=35, sel=2, out0=00, out1=00, out2=00
# KERNEL: ---------- Scoreboard ---------                    3
# KERNEL: data_in=35, sel=2, out0=00, out1=00, out2=00
# KERNEL: ---------- Monitor ---------                    4
# KERNEL: data_in=35, sel=2, out0=00, out1=00, out2=00
# RUNTIME: Info: RUNTIME_0068 environment.sv (44): $finish called.

正如我预期的那样,当监视器运行时,out2=35,但没有给出

请建议我需要在代码中更改一些内容?

verilog system-verilog
1个回答
0
投票

问题出在显示器上。

  task main();
    repeat(1)
      #3;

第一个问题是延迟:

#3;

main
任务在时间0开始运行。
#3
延迟将时间提前3个时间单位(3ns)。 也就是说,当您在监视器中构造
trans
对象时。 当您查看波形时,
out2
在 3ns 处为 0。 您需要等到
out2
在 25ns 时刻变为 'h35。 您可以通过将延迟更改为:

#30ns;
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