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-- Company:

-- Engineer:

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-- Create Date:    14:35:25 06/11/2015

-- Design Name:

-- Module Name:    Binary2bcd - Behavioral

-- Project Name:

-- Target Devices:

-- Tool versions:

-- Description:

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-- Dependencies:

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-- Revision:

-- Revision 0.01 - File Created

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library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

use ieee.std_logic_unsigned.all;

entity Binary2bcd is

    Port ( binary_in : in  STD_LOGIC_VECTOR (7 downto 0);

           sela : in  STD_LOGIC;

           selb : in  STD_LOGIC;

           segment7 : out  STD_LOGIC_VECTOR (6 downto 0));

end Binary2bcd;

architecture Behavioral of Binary2bcd is

begin

p1: process (sela, selb, binary_in) is

 variable hex_src : std_logic_vector (4 downto 0) ;

 variable bcd     : std_logic_vector (11 downto 0) ;

 variable act : STD_LOGIC_VECTOR (3 downto 0);

 variable ones : STD_LOGIC_VECTOR (3 downto 0);

 variable tens : STD_LOGIC_VECTOR (3 downto 0);

 variable huns : STD_LOGIC_VECTOR (3 downto 0);

 variable sel : STD_LOGIC_VECTOR (1 downto 0);

begin

    bcd             := (others => '0') ;

    bcd(2 downto 0) := binary_in(7 downto 5) ;

    hex_src         := binary_in(4 downto 0) ;

    sel             := sela & selb;

    for i in hex_src'range loop

        if bcd(3 downto 0) > "0100" then

            bcd(3 downto 0) := bcd(3 downto 0) + "0011" ;

        end if ;

        if bcd(7 downto 4) > "0100" then

            bcd(7 downto 4) := bcd(7 downto 4) + "0011" ;

        end if ;

        -- No roll over for hundred digit, since in 0 .. 2

        bcd := bcd(10 downto 0) & hex_src(hex_src'left) ; -- shift bcd + 1

new entry

        hex_src := hex_src(hex_src'left - 1 downto hex_src'right) & '0' ;

-- shift src + pad with 0

    end loop ;

    huns := bcd(11 downto 8);

    tens := bcd(7  downto 4);

    ones := bcd(3  downto 0);

 case sel is

   when "00" =>   act := huns;

   when "01" =>   act := tens;

   when "10" =>   act := ones;

   when "11" =>   act := ones;

    when others => act := ones;

 end case;

 case act is

    when "0000"=> segment7 <="0000001";  -- '0'

    when "0001"=> segment7 <="1001111";  -- '1'

    when "0010"=> segment7 <="0010010";  -- '2'

    when "0011"=> segment7 <="0000110";  -- '3'

    when "0100"=> segment7 <="1001100";  -- '4'

    when "0101"=> segment7 <="0100100";  -- '5'

    when "0110"=> segment7 <="0100000";  -- '6'

    when "0111"=> segment7 <="0001111";  -- '7'

    when "1000"=> segment7 <="0000000";  -- '8'

    when "1001"=> segment7 <="0000100";  -- '9'

    when others=> segment7 <="1111111";

 end case;

 ---segment7 <= bcd(6 downto 0);

end process;

end Behavioral;