VHDL Input 8 Bit to 4 Bit BCD Seven Segment

Rangkaian Logika dengan bahasa VHDL,
contoh soal:
"Write the behavioral VHDL code for converting an 8-bit unsigned binary number to two 4-bit BCD numbers. These two BCD numbers represent the tenth and unit digits of a decimal number. Also, turn on the decimal point LED for the unit digit if the 8-bit binary number is in the one hundreds range, and turn on the decimal point LED for the tenth digit if the 8-bit binary number is in the two hundreds range. This circuit is used as the output circuit for many designs in later chapters."

Jawabannya :

library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

use IEEE.NUMERIC_STD.ALL;

-- Uncomment the following library declaration if using

-- arithmetic functions with Signed or Unsigned values

--use IEEE.NUMERIC_STD.ALL;

-- Uncomment the following library declaration if instantiating

-- any Xilinx primitives in this code.

--library UNISIM;

--use UNISIM.VComponents.all;

entity Tugas2 is

    Port ( 

                   number   : in  std_logic_vector (7 downto 0);

      hundreds : out std_logic_vector (6 downto 0);

      tens     : out std_logic_vector (6 downto 0);

      ones     : out std_logic_vector (6 downto 0)

                                );

end Tugas2;

architecture Behavioral of Tugas2 is

signal ratusan,puluhan,satuan : STD_LOGIC_VECTOR (3 downto 0);

begin

   bin_to_bcd : process (number)

      -- Internal variable for storing bits

      variable shift : unsigned(19 downto 0);

      -- Alias for parts of shift register

      alias num is shift(7 downto 0);

      alias one is shift(11 downto 8);

      alias ten is shift(15 downto 12);

      alias hun is shift(19 downto 16);

   begin

      -- Clear previous number and store new number in shift register

      num := unsigned(number);

      one := X"0";

      ten := X"0";

      hun := X"0";

      -- Loop eight times

      for i in 1 to num'Length loop

         -- Check if any digit is greater than or equal to 5

         if one >= 5 then

            one := one + 3;

         end if;

         if ten >= 5 then

            ten := ten + 3;

         end if;

         if hun >= 5 then

            hun := hun + 3;

         end if;

         -- Shift entire register left once

         shift := shift_left(shift, 1);

      end loop;

      -- Push decimal numbers to output

      ratusan     <= std_logic_vector(hun);

      puluhan     <= std_logic_vector(ten);

      satuan      <= std_logic_vector(one);

   end process;

               

                                PROCESS (ratusan) --seven segmen 1

                begin

                case  ratusan is

                when "0000"=> hundreds <="0000001";  -- '0'

                when "0001"=> hundreds <="1001111";  -- '1'

                when "0010"=> hundreds <="0010010";  -- '2'

                when "0011"=> hundreds <="0000110";  -- '3'

                when "0100"=> hundreds <="1001100";  -- '4'

                when "0101"=> hundreds <="0100100";  -- '5'

                when "0110"=> hundreds <="0100000";  -- '6'

                when "0111"=> hundreds <="0001111";  -- '7'

                when "1000"=> hundreds <="0000000";  -- '8'

                when "1001"=> hundreds <="0000100";  -- '9'

                when others=> hundreds <="1111111";

                end case;

                end process;

               

                PROCESS (puluhan) --seven segmen 2

                begin

                case  puluhan is

                when "0000"=> tens <="0000001";  -- '0'

                when "0001"=> tens <="1001111";  -- '1'

                when "0010"=> tens <="0010010";  -- '2'

                when "0011"=> tens <="0000110";  -- '3'

                when "0100"=> tens <="1001100";  -- '4'

                when "0101"=> tens <="0100100";  -- '5'

                when "0110"=> tens <="0100000";  -- '6'

                when "0111"=> tens <="0001111";  -- '7'

                when "1000"=> tens <="0000000";  -- '8'

                when "1001"=> tens <="0000100";  -- '9'

                when others=> tens <="1111111";

                end case;

                end process;

               

                PROCESS (satuan) --seven segmen 3

                begin

                case  satuan is

                when "0000"=> ones <="0000001";  -- '0'

                when "0001"=> ones <="1001111";  -- '1'

                when "0010"=> ones <="0010010";  -- '2'

                when "0011"=> ones <="0000110";  -- '3'

                when "0100"=> ones <="1001100";  -- '4'

                when "0101"=> ones <="0100100";  -- '5'

                when "0110"=> ones <="0100000";  -- '6'

                when "0111"=> ones <="0001111";  -- '7'

                when "1000"=> ones <="0000000";  -- '8'

                when "1001"=> ones <="0000100";  -- '9'

                when others=> ones <="1111111";

                end case;

                end process;

               

end Behavioral;