제가 리모콘 버튼을 누르면 라인트레이서가 전진하고
버튼을 떄면 그 전진한 거리를 기억하여 제자리로 후진하게 만들고
다시 그 전후진한 거리를 기억하여 전후진을 반복하는 소스코드를 짜고있습니다.
아래 코드중 틀린 부분을 설명과 어떻게 바꿔야하는지 질문입니다.
 
-- IRobLab 3000
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
entity rf_robot2 is
Port ( rstb : in std_logic;
           clk_4m : in std_logic;
     restore : in std_logic;
           rf_data : in std_logic_vector(2 downto 0);
           mtl : out std_logic_vector(3 downto 0);
           mtr : out std_logic_vector(3 downto 0));
end rf_robot2;
architecture Behavioral of rf_robot2 is
signal forward : std_logic;
signal mtl_speed : std_logic_vector(1 downto 0);
signal mtr_speed : std_logic_vector(1 downto 0);
signal speed_l : integer range 0 to 250000;
signal speed_r : integer range 0 to 250000;
signal motor_lcnt : integer range 0 to 250000;
signal phase_lclk : std_logic;
signal phase_clk : std_logic;
signal restore1 : std_logic;
signal motor_rcnt : integer range 0 to 250000;
signal mcnt : integer range 0 to 250000;
signal phase_rclk : std_logic;
signal phase_lcnt : std_logic_vector(1 downto 0);
signal phase_lout : std_logic_vector(3 downto 0);
signal phase_rcnt : std_logic_vector(1 downto 0);
signal phase_rout : std_logic_vector(3 downto 0);
signal cnt : integer range 0 to 250000;
begin
 process(rf_data)
 begin
 forward <= rf_data(2);
  case rf_data is
    when "100" =>   -- forward
     mtl_speed <= "11";
     mtr_speed <= "11";
 when "000" =>   -- reverse
     mtl_speed <= "11";
     mtr_speed <= "11";
    when "110" =>   -- turn right
     mtl_speed <= "11";
     mtr_speed <= "00";
    when "101" =>   -- turn left
     mtl_speed <= "00";
     mtr_speed <= "11";
    when "010" =>   -- reverse turn right
     mtl_speed <= "00";
     mtr_speed <= "11";
    when "001" =>   -- turn left
     mtl_speed <= "11";
     mtr_speed <= "00";
    when others =>
     mtl_speed <= "00";
     mtr_speed <= "00";
   end case;
 end process;
 process(mtl_speed,phase_clk,cnt,restore1)
 begin
  if(cnt=0 and restore1 ='1') then
 speed_l <=0;
  elsif rising_edge(phase_clk) then
   case mtl_speed is
   when "00" =>
    speed_l <= 0;
   when "01" =>
    speed_l <= 124999;
   when "10" =>
    speed_l <= 62500;
   when "11" =>
    speed_l <= 50000;
   when others =>
    speed_l <= 50000;
  end case;
  end if;
  end process;
 process(mtr_speed,phase_clk,cnt,restore1)
 begin
  if(cnt=0 and restore1 ='1') then
 speed_r <=0;
  elsif rising_edge(phase_clk) then
   case mtr_speed is
   when "00" =>
    speed_r <= 0;
   when "01" =>
    speed_r <= 124999;
   when "10" =>
    speed_r <= 62500;
   when "11" =>
    speed_r <= 50000;
   when others =>
    speed_r <= 50000;
  end case;
  end if;
  end process;
process(rstb,clk_4m)
 begin
   if rstb = '0' then
   phase_clk <= '0';
   mcnt <=0;
  elsif rising_edge(clk_4m) then
   if mcnt >= 50000 then
    phase_clk <= not phase_clk;
  mcnt <=0;
   else
     mcnt <=mcnt+1;
   end if;
  end if;
 end process;
process(rstb, speed_l, clk_4m, motor_lcnt)
 begin
   if rstb = '0' or speed_l = 0 then
   motor_lcnt <= 0;
   phase_lclk <= '0';
  elsif rising_edge(clk_4m) then
   if motor_lcnt >= speed_l then
    motor_lcnt <= 0;
    phase_lclk <= not phase_lclk;
   else
    motor_lcnt <= motor_lcnt + 1;
   end if;
  end if;
 end process;
process(rstb, speed_r, clk_4m, motor_rcnt)
 begin
   if rstb = '0' or speed_r = 0 then
   motor_rcnt <= 0;
   phase_rclk <= '0';
  elsif rising_edge(clk_4m) then
   if motor_rcnt >= speed_r then
    motor_rcnt <= 0;
    phase_rclk <= not phase_rclk;
   else
    motor_rcnt <= motor_rcnt + 1;
   end if;
  end if;
 end process;
process(rstb, phase_lclk, phase_lcnt)
 begin
  if rstb = '0' then
   phase_lcnt <= (others => '0');
  elsif rising_edge(phase_lclk) then
   phase_lcnt <= phase_lcnt + 1;
  end if;
 end process;
process(rstb, phase_lcnt)
 begin
  if rstb = '0' then
   phase_lout <= (others => '0');
  else
   case (phase_lcnt) is
    when "00" => phase_lout <= "1000";
    when "01" => phase_lout <= "0100";
    when "10" => phase_lout <= "0010";
    when "11" => phase_lout <= "0001";
    when others => phase_lout <= "0000";
   end case;
  end if;
 end process;
process(rstb, phase_rclk, phase_rcnt)
 begin
  if rstb = '0' then
   phase_rcnt <= (others => '0');
  elsif rising_edge(phase_rclk) then
   phase_rcnt <= phase_rcnt + 1;
       if(restore1 = '0') then
   cnt <= cnt +1;
 elsif (cnt/=0) then
   cnt <=cnt-1;
 end if;
  end if;
 end process;
process(rstb, phase_rcnt)
 begin
  if rstb = '0' then
   phase_rout <= (others => '0');
  else
   case (phase_rcnt) is
    when "00" => phase_rout <= "1000";
    when "01" => phase_rout <= "0100";
    when "10" => phase_rout <= "0010";
    when "11" => phase_rout <= "0001";
    when others => phase_rout <= "0000";
   end case;
  end if;
 end process;
process(restore, phase_clk)
 begin
  if rising_edge(phase_clk) then
   restore1 <= restore;
  end if;
 end process;
 
 mtl(0) <= phase_lout(0) when restore1 ='0' else phase_lout(3);
 mtl(1) <= phase_lout(1) when restore1 ='0' else phase_lout(2);
 mtl(2) <= phase_lout(2) when restore1 ='0' else phase_lout(1);
 mtl(3) <= phase_lout(3) when restore1 ='0' else phase_lout(0);
 mtr(0) <= phase_rout(3) when restore1 ='0' else phase_rout(0);
 mtr(1) <= phase_rout(2) when restore1 ='0' else phase_rout(1);
 mtr(2) <= phase_rout(1) when restore1 ='0' else phase_rout(2);
 mtr(3) <= phase_rout(0) when restore1 ='0' else phase_rout(3);
end Behavioral;