///////////////////////////////////////////////////If you have any question about this testbench//please get in touch with me:  llbt24@zju.edu.cn///////////////////////////////////////////////////////`timescale 1ns/1nsmodule testHDLC;reg RXD,RXCLK,RESET;wire TXCLK;wire[7:0] TXD;wire[2:0] TXDS;reg isfix;reg[7:0] bytedate;reg[2:0] bytekind;reg iswrong;reg isinsert;integer RXDOUT;integer insertnum;integer bittest;integer bitstream;integer bytecount;integer framecount;integer TXD_REF_int;integer TXDS_REF_int;integer seednum;reg[7:0] TXD_REF;reg[2:0] TXDS_REF;hdlc_recv instance(RXD,RXCLK,RESET,TXD,TXCLK,TXDS);//HDLC instance(RXD,RXCLK,RESET,TXD,TXCLK,TXDS);always #10 RXCLK=!RXCLK;initial   begin      RESET=1; RXCLK=0; RXD=1;      isfix=0; bytedate=0; bytekind=0;      iswrong=0; bitstream=0; bytecount=0; framecount=0; isinsert=1;      TXD_REF=0; TXDS_REF=0;            $hello;      #20 RESET=0;      #20 RESET=1;          seednum=21; $seed(seednum);      #70 task_flag_gen; framecount=framecount+1;   //framecount=1;                   isfix=1; bytedate=8'h23; bytekind=3'b110; task_byte_fix; task_byte_gen; //1-5	  isfix=1; bytedate=8'h67; bytekind=3'b101; task_byte_fix; task_byte_gen; 	  isfix=0; bytedate=8'h00; bytekind=3'b100; task_byte_fix; task_byte_gen;	  isfix=1; bytedate=8'h8F; bytekind=3'b100; task_byte_fix; task_byte_gen;	  isfix=1; bytedate=8'hFE; bytekind=3'b100; task_byte_fix; task_byte_gen;	  isfix=1; bytedate=8'h7F; bytekind=3'b100; task_byte_fix; task_byte_gen; //6-10	  isfix=0; bytedate=8'h00; bytekind=3'b100; task_byte_fix; task_byte_gen;	  isfix=1; bytedate=8'hC3; bytekind=3'b100; task_byte_fix; task_byte_gen;	  isfix=1; bytedate=8'hE7; bytekind=3'b100; task_byte_fix; task_byte_gen;	  isfix=1; bytedate=8'h10; bytekind=3'b100; task_byte_fix; task_byte_gen;	  isfix=1; bytedate=8'h3F; bytekind=3'b011; task_byte_fix; task_byte_gen; //11-15	  //          task_flag_gen;//          insertnum=11; task_ones_insert;          task_flag_gen; framecount=framecount+1;   //framecount=2;	  isfix=0; bytedate=8'h00; bytekind=3'b110; task_byte_fix; task_byte_gen; //1-5	  isfix=1; bytedate=8'h03; bytekind=3'b101; task_byte_fix; task_byte_gen;	  isfix=1; bytedate=8'hF2; bytekind=3'b010; task_byte_fix; task_byte_gen;	  task_flag_gen;	  task_flag_gen;	  task_flag_gen;//	  insertnum=2; task_ones_insert;	  task_flag_gen; framecount=framecount+1;   //framecount=3;	  	  isfix=1; bytedate=8'h45; bytekind=3'b010; task_byte_fix; task_byte_gen; //1-5	  task_flag_gen;	  insertnum=0; task_ones_insert;	  task_flag_gen; framecount=framecount+1;   //framecount=4;	  isfix=0; bytedate=8'h00; bytekind=3'b110; task_byte_fix; task_byte_gen; //1-5	  isfix=1; bytedate=8'h7E; bytekind=3'b101; task_byte_fix; task_byte_gen;	  isfix=1; bytedate=8'hF7; bytekind=3'b100; task_byte_fix; task_byte_gen;	  isfix=1; bytedate=8'h7E; bytekind=3'b011; task_byte_fix; task_byte_gen;	  	  task_flag_gen;	  insertnum=21; task_ones_insert;	  task_flag_gen; framecount=framecount+1;   //framecount=5;	  	  isfix=1; bytedate=8'h37; bytekind=3'b110; task_byte_fix; task_byte_gen; //1-5	  isfix=0; bytedate=8'h00; bytekind=3'b101; task_byte_fix; task_byte_gen;	  repeat(61)    	    begin		isfix=0; bytedate=8'h00; bytekind=3'b100; task_byte_fix; task_byte_gen; //3-63	    end 	  isfix=1; bytedate=8'h1F; bytekind=3'b011; task_byte_fix; task_byte_gen; //64	  	  task_flag_gen;          insertnum=5; task_ones_insert;	  task_flag_gen; framecount=framecount+1;   //framecount=6;	  isfix=1; bytedate=8'h37; bytekind=3'b110; task_byte_fix; task_byte_gen; //1-5	  isfix=0; bytedate=8'h00; bytekind=3'b101; task_byte_fix; task_byte_gen;	  repeat(62)	    begin                isfix=0; bytedate=8'h00; bytekind=3'b100; task_byte_fix; task_byte_gen; //3-64	    end	  isfix=1; bytedate=8'h56; bytekind=3'b001; task_byte_fix; task_byte_gen; //65	  task_flag_gen;	  insertnum=3; task_ones_insert;          task_flag_gen; framecount=framecount+1;   //framecount=7;          isfix=0; bytedate=8'h00; bytekind=3'b110; task_byte_fix; task_byte_gen; //1-5	  isfix=1; bytedate=8'h3E; bytekind=3'b010; task_byte_fix; task_byte_gen;	  task_flag_gen;          insertnum=20; task_ones_insert;          task_flag_gen; framecount=framecount+1;   //framecount=8;          isfix=1; bytedate=8'h54; bytekind=3'b110; task_byte_fix; task_byte_gen; //1-5	  isfix=0; bytedate=8'h00; bytekind=3'b101; task_byte_fix; task_byte_gen;	  repeat(125)	    begin		isfix=0; bytedate=8'h00; bytekind=3'b100; task_byte_fix; task_byte_gen; //3-127	    end	  isfix=1; bytedate=8'h5D; bytekind=3'b001; task_byte_fix; task_byte_gen; //128	  	            task_flag_gen;	  insertnum=7; task_ones_insert;	  task_flag_gen; framecount=framecount+1;          isinsert=0;                    //framecount=9;	  isfix=1; bytedate=8'h37; bytekind=3'b110; task_byte_fix; task_byte_gen; //1-5	  isfix=1; bytedate=8'h17; bytekind=3'b101; task_byte_fix; task_byte_gen;	  isfix=1; bytedate=8'hEC; bytekind=3'b111; task_byte_fix; task_byte_gen;	  isinsert=1;	  isfix=1; bytedate=8'h32; bytekind=3'b111; task_byte_fix; task_byte_gen;	  isfix=0; bytedate=8'h00; bytekind=3'b111; task_byte_fix; task_byte_gen;	  task_flag_gen;	  insertnum=2; task_ones_insert;	  task_flag_gen; framecount=framecount+1;   //framecount=10;	  	  isfix=1; bytedate=8'h34; bytekind=3'b110; task_byte_fix; task_byte_gen; //1-5	  isfix=1; bytedate=8'h5A; bytekind=3'b101; task_byte_fix; task_byte_gen;	  isfix=0; bytedate=8'h00; bytekind=3'b100; task_byte_fix; task_byte_gen;	  isfix=0; bytedate=8'h00; bytekind=3'b100; task_byte_fix; task_byte_gen;	  isfix=0; bytedate=8'h00; bytekind=3'b100; task_byte_fix; task_byte_gen;	  isfix=1; bytedate=8'hC6; bytekind=3'b011; task_byte_fix; task_byte_gen; //6-10	  task_flag_gen;	  insertnum=11; task_ones_insert;          $finish;   endalways @(posedge RXCLK)    task_display_RXD;always @(negedge TXCLK)    begin       $readresult(TXD_REF_int,TXDS_REF_int);       TXD_REF=TXD_REF_int;       TXDS_REF=TXDS_REF_int;//       if(TXD==TXD_REF&&TXDS==TXDS_REF)//	  $display("Current byte is OK\n");//       else//	  $display("Current byte is WRONG\n");    end       task task_flag_gen;   begin      bytecount=0;      #1      $display("------------------------\n");      $display("\tnew flag\n");      $display("------------------------\n");      repeat(8)         @(negedge RXCLK) begin $flag(RXDOUT); RXD=RXDOUT; end          #10;   endendtasktask task_ones_insert;   begin      #1      $display("************************\n");      $display("\tones_insert\n");      $display("************************\n");      repeat(insertnum)         @(negedge RXCLK) RXD=1;      if(insertnum)        #10;   endendtasktask task_byte_fix;   $fix(isfix,bytedate,bytekind);endtasktask task_byte_gen;   begin      bytecount=bytecount+1;      #1      $display("^^^^^^^^^^^^^^^^^^^^^^^^\n");       $display("\tnew byte   %0d-%0d\n",framecount,bytecount);      $display("^^^^^^^^^^^^^^^^^^^^^^^^\n");      while(bitstream<8)          @(negedge RXCLK)              begin       	          $stuff(bittest);		  if(isinsert&&bittest)	             begin RXD=iswrong; $display("--the next bit is bitstuff--\n"); end		  else	             begin $byte(RXDOUT); RXD=RXDOUT; bitstream=bitstream+1; end              end      bitstream=0;      #10;   endendtasktask task_display_RXD;    $display("At time:  %0t\t\t",$time,"RXD=%b",RXD);endtaskendmodule