generator模块

`ifndef GENERATOR
`define GENERATOR

class generator;

  mailbox gen2drv;
  
  function new (mailbox gen2drv_new);
    if(gen2drv_new == null)begin
      $display("%0t -> generator : ERROR -> gen2drv is null",$time);
      $finish;
    end
    else
      this.gen2drv = gen2drv_new;
  endfunction 

  task run(int num_tr = 200);
    transaction tr;
    
    //random
    repeat(num_tr)begin
      tr = new();
      assert(tr.randomize());
      $display("%0t -> generator : tr is %s",$time,tr.convert2string_in());
      gen2drv.put(tr);
    end

    //constraint operand with 'h00 or 'hff
    repeat(num_tr)begin
      tr = new();
      assert(tr.randomize() with {A inside {'h0,'hff}; B inside {'h0,'hff};});
      $display("%0t -> generator : tr is %s",$time,tr.convert2string_in());
      gen2drv.put(tr);
    end

  endtask

endclass  

`endif