bcd_add_1dig.vhd

將正在順時針或逆時針旋轉的步進馬達目前角度顯示在ＬＣＭ上。

--***************************************
--*        1 Digital BCD Adder		*
--*    Filename : BCD_ADD_1DIG.VHD 	*
--***************************************

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
use work.STEP_MOTOR_DEGREE_FORWARD_REVERSE_LCD_PACK.all;

entity BCD_ADD_1DIG is
    Port ( CIN   : in std_logic;
           X     : in std_logic_vector(3 downto 0);
           Y     : in std_logic_vector(3 downto 0);
           SUM   : out std_logic_vector(3 downto 0);
           CARRY : out std_logic);
end BCD_ADD_1DIG;

architecture Behavioral of BCD_ADD_1DIG is
  signal C_OUT        : std_logic;
  signal FLAG         : std_logic;
  signal SUM_BIN      : std_logic_vector(3 downto 0);
  signal COMPENSATION : std_logic_vector(3 downto 0);
begin
  FLAG         <= C_OUT or (SUM_BIN(1) and SUM_BIN(3)) or (SUM_BIN(2) and SUM_BIN(3)); 
  COMPENSATION <= "0110" when FLAG = '1' else "0000";
  CARRY        <= FLAG;

BIN_ADD1: BIN_ADD_4BIT port map (CIN,X,Y,SUM_BIN,C_OUT);
BIN_ADD2: BIN_ADD_4BIT port map ('0',SUM_BIN,COMPENSATION,SUM);   

end Behavioral;