ENTITY conta IS PORT(
reset : IN BIT;
carga : IN BIT;
arriba : IN BIT;
clk : IN BIT;
data : IN BIT_VECTOR (3 DOWNTO 0);
valor : BUFFER BIT_VECTOR (3 DOWNTO 0)
);
END conta;
ARCHITECTURE arc_conta OF conta IS
BEGIN
PROCESS (reset, carga, clk)
BEGIN
IF (clk'EVENT AND clk='1') THEN
IF reset='1' THEN
valor <= "0000";
ELSIF carga='1' THEN
valor <= data;
ELSIF arriba='1' THEN
valor <= valor + 1;
ELSE
valor <= valor - 1;
END IF;
END IF;
END PROCESS;
END arc_conta;