library ieee;use ieee.std_logic_1164.all;use ieee.std_logic_signed.all;use ieee.std_logic_arith.all;use std.TEXTIO.all;entity tb isend tb;architecture a_tb of tb is	component Add2In	port(D1:in std_logic_vector(7 downto 0);	     D2:in std_logic_vector(7 downto 0);	     Q: out std_logic_vector(8 downto 0);	     clk:in std_logic);	end component;	signal D1:std_logic_vector(7 downto 0):=(others=>'0');	signal D2:std_logic_vector(7 downto 0):=(others=>'0');	signal Q:std_logic_vector(8 downto 0);	signal clk:std_logic:='0';	signal Dlatch:boolean:=false;	signal SResult: integer;	begin	    dut:Add2In	    port map(D1=>D1,	             D2=>D2,	             Q=>Q,                clk=>clk);       clk<=not clk after 20 us;     	                process                  file InputD:text open read_mode is "TestData.dat";           variable DLine:LINE;           variable good:Boolean;           variable Data1:integer;           variable Data2:integer;                      begin               wait until clk='1' and clk'event;               readline(InputD,DLine);               read(DLine,Data1,good);               read(Dline,Data2,good);               if(good) then                   D1<=CONV_STD_LOGIC_VECTOR(Data1,8);                   D2<=CONV_STD_LOGIC_VECTOR(Data2,8);               else                  assert false report"End of Reading INput File!"                     severity error;               end if;           end process;           process               file InputR:text open read_mode is "Result.dat";               variable RLine :LINE;               variable Result:integer;               begin                   wait until clk='1' and clk'event;                   Dlatch<=true;                   if Dlatch then                       readline(InputR,RLine);                      read(RLine,Result);                      SResult<=Result;                      if SResult/=Q then                          assert false report"Two values are different"                          severity warning;                      end if;                  end if;              end process;          end a_tb;