-- Registre 4 bits

ENTITY accu IS
  PORT (
		i 	: in bit_vector(3 downto 0);
		ck      : in bit;
		o 	: out bit_vector(3 downto 0);
                vdd     : in bit;
                vss     : in bit
    );
END accu;

-- Architecture Declaration

ARCHITECTURE structural_view OF accu IS


  COMPONENT sff1_x4
    PORT (
	  ck	 : in  BIT;
	  i	 : in  BIT;
	  q	 : out BIT;
	  vdd	 : in  BIT;
	  vss	 : in  BIT
	  );
  END COMPONENT;

-- Assemblage des instances

BEGIN

-- generation des sorties 

  reg_0 : sff1_x4 port map(ck, i(0), o(0), vdd, vss);

  reg_1 : sff1_x4 port map(ck, i(1), o(1), vdd, vss);

  reg_2 : sff1_x4 port map(ck, i(2), o(2), vdd, vss);

  reg_3 : sff1_x4 port map(ck, i(3), o(3), vdd, vss);

end structural_view;