LIBRARY IEEE;

USE IEEE.std_logic_1164.ALL;

USE IEEE.std_logic_unsigned.ALL;

USE IEEE.std_logic_arith.ALL;

ENTITY step_motor IS

PORT(

f, p, d: INSTD_LOGIC:='0';

speed : inSTD_LOGIC_VECTOR(1 downto 0);

coil : OUTSTD_LOGIC_VECTOR(3 downto 0)

);

END step_motor;

ARCHITECTURE behavior OF step_motor IS

SIGNAL ind_coil: STD_LOGIC_VECTOR(3 downto 0) := "0001";

SIGNAL clk_scan: STD_LOGIC;

SIGNAL PHASE,DIRECTION:STD_LOGIC;

signal t:std_logic_vector(3 downto 0);

signal comp:integer range 0 to 2500 ;

SIGNAL osc:STD_LOGIC;

BEGIN

coil <= t;

process(f,osc)

variable delay:integer range 0 to 50;

begin

if (f'event and f='1') then

if delay>=50 then delay:=0;osc<=not osc;

else delay:=delay+1;

end if;

end if;

if (osc'event and osc='1') then

case speed is

when "10" => if comp<2500 then comp<=comp+1;

else comp<=comp;

end if;

when "01" => if comp>2 then comp<=comp-1;

else comp<=comp;

end if;

when others => if comp<2 then comp<=2;

else comp<=comp;

end if;

end case;

end if;

end process;

PROCESS

VARIABLE d_ff: integer range 0 to 2500;

BEGIN

WAIT UNTIL f = '1';

if d_ff >= comp then

d_ff :=0; clk_scan <= not CLK_SCAN;

else

d_ff := d_ff + 1;

end if;

END PROCESS ;

PROCESS(F)

VARIABLE B:STD_LOGIC;

BEGIN

IF (F'EVENT AND F='1') THEN B:=(P and (b and P) );

IF B='1' THEN PHASE<=NOT PHASE ;B:='0';

ELSIF P='0' THEN PHASE<=PHASE;B:='1';

END IF;

END IF;

END PROCESS;

PROCESS(F)

VARIABLE B:STD_LOGIC;

BEGIN

IF (F'EVENT AND F='1') THEN B:=(D and (b and D) );

IF B='1' THEN DIRECTION<=NOT DIRECTION ;B:='0';

ELSIF D='0' THEN DIRECTION<=DIRECTION;B:='1';

END IF;

END IF;

END PROCESS;

motor:

process

begin

--if (clk_scan'event and clk_scan='1') then

WAIT UNTIL clk_scan= '0';

CASE phase IS

WHEN '1' =>

IF direction = '0' THEN

IF ((ind_coil = "1001") or (ind_coil = "0000")) THEN

ind_coil <= "0001";

ELSE

ind_coil <= (ind_coil(2 downto 0) & ind_coil(3));

END IF;

ELSE

IF ((ind_coil = "1001") or (ind_coil = "0000")) THEN

ind_coil <= "1000";

ELSE

ind_coil <= (ind_coil(0) & ind_coil(3 downto 1));

END IF;

END IF;

WHEN OTHERS =>

ind_coil<=IND_COIL;

END CASE;

t<=not ind_coil;

END PROCESS motor;

END behavior;