For loop, array and a step motor, VHDL

Looking the code it seems you are a C programmer. The for loop statement in vhdl it's different from the for sentence of C. For loop is not a sequential statement. It is used when you need to copy paste many times a circuit cell ( iterative circuit ).

Probably you're tried to explore the 8 output value you write in secuencia. A counter may solve it:

architecture Behavioral of main is

signal sec_reg, sec_next : unsigned(2 downto 0);

secuencia := ("0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111");

begin

process( clr_n, clk )

begin

if( clr_n = '0' ) then

sec_reg <= ( others => '0' );

sal_reg <= "0000";

elsif( clk'event and clk = '1 ) then

sec_reg <= sec_next;

sal_next <= sal_next;

end if;

end process;

sec_next <= sec_reg + 1;

motor <= sal_reg;

process(sec_reg)

begin

case sec_reg is

when "0000" =>

sal_next <= "0000";

when "0001" =>

sal_next <= "0001";

-- complete the rest

end case;

end process;

end Behavioral;

There something missing in this code. To drive a stepper motor you need to slow down the clock.