Codec7segmentos

Library ieee;
use ieee.std_logic_1164.all;

entity bcd_7seg is

    port(
            bcd : in std_logic_vector(3 downto 0);
            D: out std_logic_vector(6 downto 0)
        );

     attribute pin_numbers of bcd_7seg: entity is
    "D(6):21 D(5):20 D(4):19 "
&   "D(3):18 D(2):17 D(1):16 D(0):15 "    -- se deja un espacio despues de g:15 para que al concatenar
&   "BCD(0):11 BCD(1):10 BCD(2):9 BCD(3):8"; -- haya una separacion entre literales

end bcd_7seg;

architecture cto of  bcd_7seg is
constant zero : std_logic_vector(6 downto 0) := "0000001";
constant uno  : std_logic_vector(6 downto 0) := "1001111";
constant dos  : std_logic_vector(6 downto 0) := "0010010";
constant tres : std_logic_vector(6 downto 0) := "0000110";
constant quat : std_logic_vector(6 downto 0) := "1001100";
constant qint : std_logic_vector(6 downto 0) := "0100100";
constant sixt : std_logic_vector(6 downto 0) := "0100000";
constant sept : std_logic_vector(6 downto 0) := "0001111";
constant octo : std_logic_vector(6 downto 0) := "0000000";
constant nono : std_logic_vector(6 downto 0) := "0000100";
constant OFF  : std_logic_vector(6 downto 0) := "-------";

    begin

        Conv_codigo : process(BCD)

        begin

          case bcd is
            when "0000" => D <= zero;
            when "0001" => D <= uno;
            when "0010" => D <= dos;
            when "0011" => D <= tres;
            when "0100" => D <= quat;
            when "0101" => D <= qint;
            when "0110" => D <= sixt;
            when "0111" => D <= sept;
            when "1000" => D <= octo;
            when "1001" => D <= nono;
            when others => D <= OFF;

          end case;

        end process conv_codigo;

    end cto;