library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
---- Uncomment the following library declaration if instantiating
---- any Xilinx primitives in this code.
--library UNISIM;
--use UNISIM.VComponents.all;
entity motor_sm is
port (
clk : in std_logic; -- input to determine speed of rotation
rst : in std_logic; -- resets and initializes the circuit
en : in std_logic; -- determines whether motor rotating or holding (0 holding, 1 rotating)
dir : in std_logic; -- motor direction control (0 forward, 1 backward)
position_feedback : in std_logic_vector (3 downto 0); -- motor phase feedback vector (ph1,ph2,ph3,ph4)
ph1 : out std_logic; -- output to motor phase 1
ph2 : out std_logic; -- output to motor phase 2
ph3 : out std_logic; -- output to motor phase 3
ph4 : out std_logic -- output to motor phase 4
);
end motor_sm;
architecture Behavioral of motor_sm is
begin
process (clk)
begin
if (rst = '1') then
ph1 <= '1';
ph2 <= '0';
ph3 <= '0';
ph4 <= '0';
elsif (clk'event and clk = '1') then
if en = '1' then
case position_feedback is
--description of phase1 behaviour
when "1000" =>
--In phase1 -> forward step
if dir = '0' then
ph1 <= '0';
ph2 <= '1';
ph3 <= '0';
ph4 <= '0';
--In phase1 -> backward step
elsif dir = '1' then
ph1 <= '0';
ph2 <= '0';
ph3 <= '0';
ph4 <= '1';
--In phase1 -> stay in phase1
else
ph1 <= '1';
ph2 <= '0';
ph3 <= '0';
ph4 <= '0';
end if;
--description of phase2 behaviour
when "0100" =>
--In phase2 -> forward step
if dir = '0' then
ph1 <= '0';
ph2 <= '0';
ph3 <= '1';
ph4 <= '0';
--In phase2 -> backward step
elsif dir = '1' then
ph1 <= '1';
ph2 <= '0';
ph3 <= '0';
ph4 <= '0';
--In phase2 -> stay in phase2
else
ph1 <= '0';
ph2 <= '1';
ph3 <= '0';
ph4 <= '0';
end if;
--description of phase3 behaviour
when "0010" =>
--In phase3 -> forward step
if dir = '0' then
ph1 <= '0';
ph2 <= '0';
ph3 <= '0';
ph4 <= '1';
--In phase3 -> backward step
elsif dir ='1' then
ph1 <= '0';
ph2 <= '1';
ph3 <= '0';
ph4 <= '0';
--In phase3 -> stay in phase3
else
ph1 <= '0';
ph2 <= '0';
ph3 <= '1';
ph4 <= '0';
end if;
--description of phase4 behaviour
when "0001" =>
--In phase4 -> forward step
if dir = '0' then
ph1 <= '1';
ph2 <= '0';
ph3 <= '0';
ph4 <= '0';
--In phase4 -> backward step
elsif dir = '1' then
ph1 <= '0';
ph2 <= '0';
ph3 <= '1';
ph4 <= '0';
--In phase4 -> stay in phase4
else
ph1 <= '0';
ph2 <= '0';
ph3 <= '0';
ph4 <= '1';
end if;
when others => null;
end case;
end if;
end if;
end process;
end Behavioral;
