interface_hcsr04.vhd

--------------------------------------------------------------------
-- Arquivo   : interface_hcsr04.vhd
-- Projeto   : Experiencia 4 - Interface com sensor de distancia
--------------------------------------------------------------------
-- Descricao : circuito
--             da interface HC-SR04
--------------------------------------------------------------------

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

entity interface_hcsr04 is
    port (
        clock      : in std_logic;
        reset      : in std_logic;
        medir      : in std_logic;
        echo       : in std_logic;
        trigger    : out std_logic;
        medida     : out std_logic_vector(11 downto 0); -- 3 digitos BCD
        pronto     : out std_logic;
        db_estado  : out std_logic_vector(3 downto 0) -- estado da UC
    );
end entity;

architecture interface_hcsr04_structure of interface_hcsr04 is

    component interface_hcsr04_fd is
        port(
            clock       : in std_logic;
            pulso       : in std_logic;
            gera        : in std_logic;
            zera        : in std_logic;
            registra    : in std_logic;
            fim_medida  : out std_logic;
            distancia   : out std_logic_vector(11 downto 0);
            trigger     : out std_logic
        );
    end component;

    component interface_hcsr04_uc is
        port ( 
            clock      : in  std_logic;
            reset      : in  std_logic;
            medir      : in  std_logic;
            echo       : in  std_logic;
            fim_medida : in  std_logic;
            zera       : out std_logic;
            gera       : out std_logic;
            registra   : out std_logic;
            pronto     : out std_logic;
            db_estado  : out std_logic_vector(3 downto 0) 
        );
    end component;

    signal s_gera, s_zera, s_registra, s_fim_medida : std_logic;

begin

    FD: interface_hcsr04_fd
        port map(
            clock       => clock,    
            pulso       => echo,
            gera        => s_gera,
            zera        => s_zera,
            registra    => s_registra,
            fim_medida  => s_fim_medida,
            distancia   => medida,
            trigger     => trigger
        );

    UC: interface_hcsr04_uc
        port map(
            clock       => clock,
            reset       => reset,
            medir       => medir,
            echo        => echo,
            fim_medida  => s_fim_medida,
            zera        => s_zera,
            gera        => s_gera,
            registra    => s_registra,
            pronto      => pronto,
            db_estado   => db_estado
        );


end architecture;