LIBRARY ieee;USE ieee.std_logic_1164.all;USE ieee.numeric_std.all;ENTITY control IS  port(    CLK        : in std_logic;   --4096 Hz    RESET      : in std_logic;     KEY1       : in std_logic;     KEY2       : in std_logic;     DISP_HOLD  : out    std_logic;    MEASURE    : out    std_logic;    SET_ZERO   : out    std_logic  );END control ;ARCHITECTURE behavioral_control OF control IS  type T_STATE is (START, MEASURE_CONT, MEASURE_STOP,MEASURE_INTERM);   signal ACTUAL_STATE, NEXT_STATE : T_STATE;  signal IN_DATA : std_logic_vector(1 downto 0);begin  IN_DATA(0) <= KEY1;  IN_DATA(1) <= KEY2;  STATE_TRANSITION_LOGIC: process (ACTUAL_STATE, IN_DATA)  begin    case ACTUAL_STATE is      when START =>        case IN_DATA is          when "01" => NEXT_STATE <= MEASURE_CONT;          when "10" => NEXT_STATE <= START;          when "11" => NEXT_STATE <= MEASURE_CONT;          when others => NEXT_STATE <= START;        end case;      when MEASURE_CONT =>        case IN_DATA is          when "01" => NEXT_STATE <= MEASURE_STOP;          when "10" => NEXT_STATE <= MEASURE_INTERM;          when "11" => NEXT_STATE <= MEASURE_STOP;          when others => NEXT_STATE <= MEASURE_CONT;        end case;      when MEASURE_STOP =>        case IN_DATA is          when "01" => NEXT_STATE <= MEASURE_CONT;          when "10" => NEXT_STATE <= START;          when "11" => NEXT_STATE <= START;          when others => NEXT_STATE <= MEASURE_STOP;        end case;      when MEASURE_INTERM =>	case IN_DATA is	  when "01" => NEXT_STATE <= MEASURE_STOP;	  when "10" => NEXT_STATE <= MEASURE_CONT;	  when "11" => NEXT_STATE <= MEASURE_STOP;	  when others => NEXT_STATE <= MEASURE_INTERM;	end case;       when others => NEXT_STATE <= START;      end case;    end process; -- TRANSITION_STATE_LOGIC        STATE_MEM: process (CLK)    begin      if (CLK'event and CLK = '1' ) then        if (RESET = '1') then          ACTUAL_STATE <= START;        else          ACTUAL_STATE <= NEXT_STATE;        end if;      end if;    end process; -- STATE_MEM        OUTPUT_LOGIC: process (ACTUAL_STATE)    begin      case ACTUAL_STATE is        when START =>          DISP_HOLD <= '0';          MEASURE   <= '0';          SET_ZERO  <= '1';        when MEASURE_CONT =>          DISP_HOLD <= '0';          MEASURE   <= '1';          SET_ZERO  <= '0';        when MEASURE_STOP =>          DISP_HOLD <= '0';          MEASURE   <= '0';          SET_ZERO  <= '0';        when MEASURE_INTERM =>          DISP_HOLD <= '1';          MEASURE   <= '1';          SET_ZERO  <= '0';        end case;      end process; -- OUTPUT_LOGICEND behavioral_control;