stepper motor

[Sweta Dauhawoo]

Hi I am trying to write codes for half step for stepper motor and I am using a clock divider so as I can choose the frequency of the motor. But I am getting errors can anyone help?? Thanks in advance
#
library IEEE;
use IEEE.STD_LOGIC_1164.all;
use IEEE.STD_LOGIC_unsigned.all;
use IEEE.STD_LOGIC_arith.all;


entity driver is
port(
clk : in STD_LOGIC;
start : in STD_LOGIC;
Dout : out STD_LOGIC_VECTOR(3 downto 0)
);
end driver;



architecture driver of driver is
component clkdiv
port
(
mclk : in STD_LOGIC;
clr : in STD_LOGIC_VECTOR(0 downto 0);
clk94: out STD_LOGIC
);
end component;
signal clk94 : STD_LOGIC;
begin
U1 : clkdiv
port map
(
mclk => mclk, clr => clr, clk94 => clk
);

process ( clk, start)is
variable m: std_logic_vector ( 2 downto 0);
begin
if (start ='1')then
if (rising_edge (clk)) then
m:= m +1 ;
end if;
end if;
case m is
when "000" => Dout <= "1000";
when "001" => Dout <= "1100";
when "010" => Dout <= "0100";
when "011" => Dout <= "0110";
when "100" => Dout <= "0010";
when "101" => Dout <= "0011";
when "110" => Dout <= "0001";
when others => Dout <= "1001";
end case;
end process;
end driver;

/////////////////////////
for clkdiv
library IEEE;
use IEEE.STD_LOGIC_1164.all;
use IEEE.STD_LOGIC_unsigned.all;
use IEEE.STD_LOGIC_arith.all;


entity clkdiv is
port(
mclk : in STD_LOGIC;
clr : in STD_LOGIC_VECTOR(0 downto 0);
clk94: out STD_LOGIC;
clk : out STD_LOGIC_VECTOR (2 downto 0)

);
end clkdiv;


architecture clkdiv of clkdiv is
signal q: STD_LOGIC_VECTOR (23 downto 0);

begin


process (mclk ,clr(0))
begin
if clr(0)= '1' then
q <= X"000000" ;
elsif mclk 'event and mclk = '1' then
q <= q + 1;
end if ;
end process;
clk(0)<= q(0);
clk(1)<= q(1);
clk(2)<= q(21);
clk94 <= q(19);


end clkdiv;
////////////////////////////////////////////////////////////////////////