45_test_63.vhd

这是一个对于初学者很好的vhdl实验的一些例子,希望站长的支持哦

--Page          :298 299

--Objective     :Procedure location option 

--Filename      :test_63.vhd

--Author        :Joseph Pick

entity Test_63 is
end Test_63;

architecture Behave_1 of Test_63 is
  signal Sig_Nat      : NATURAL := 0;
  signal Sig_Nat_Procedure : NATURAL := 0;

begin 

  Proc_Scope:
  process
	 variable Count      : Natural := 0;
	 variable Count_Temp_1 : Natural := 0;
	 variable Count_Temp_2 : Natural := 0;
	 variable Exit_Loop    : BOOLEAN := FALSE;
	 procedure Set_55 is
		begin 
		  If Sig_Nat = 0 then 
			 wait until Sig_Nat = 2;
			 if Count_Temp_2 /= 55 then 
				Sig_Nat_Procedure <= 55;
				Count :=55;
             Exit_Loop := TRUE ;
			 end if;
           end if;
         end Set_55;
  begin 
	Loop_1:
	loop
	  Count_Temp_2 :=Count_Temp_1 + 1;
      Set_55;
	  If Exit_Loop =TRUE then
		Count_Temp_1 := Count;
		wait on Sig_Nat_Procedure'TRANSACTION;
		Count_Temp_2 := Sig_Nat_Procedure;
		exit Loop_1;
      end if ;
	  wait for 15 ns;
    end loop loop_1;
	Count := Count + 1;
	wait for 20 ns;
  end process Proc_Scope;
  Gen_Sig_Nat:
  process
  begin
	wait for 10 ns;
	Sig_Nat <= Sig_Nat + 1;
  end process Gen_Sig_Nat;

end Behave_1;