cnt_nuevo.vhd

Sobel--Image Filter (I). An Image filtering is made over data loaded into the on board RAM and prese

library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_arith.all;
use IEEE.std_logic_unsigned.all;

entity cnt is

	generic (
		nb_width : integer:=6;
		nb_lenght : integer:=6;
		width : integer:= 63;
		lenght: integer:= 63
	);

	port (
		asinc_reset, enable_cnt : in std_logic;
		i : in std_logic_vector(nb_width-1 downto 0);
		j : in std_logic_vector(nb_lenght-1 downto 0);
		fila : out std_logic_vector(nb_lenght-1 downto 0);
		columna : out std_logic_vector(nb_width-1 downto 0);
		desborde : out std_logic
	);

end cnt;

architecture cnt_arch of cnt is

type state_values is(st0,st1,st2,st3,st4,st5,st6,st7,st8);
signal estado_presente, estado_futuro : state_values;
signal aux_desborde : std_logic;
signal aux_fil : std_logic_vector(nb_width-1 downto 0);
signal aux_col : std_logic_vector(nb_width-1 downto 0);

begin

comb : process(estado_presente, i, j)

begin

	case estado_presente is
			
		when st0 =>
			
			if (i = "000000" or j = "000000") then
				aux_desborde <= '1';
				aux_fil <= i;
				aux_col <= j;
			else
				aux_desborde <= '0';
				aux_fil <= i-'1';
				aux_col <= j-'1';
			end if;
			estado_futuro <= st1;
		
		when st1 =>

			aux_col <= j;
			if(i = "000000") then
				aux_desborde <= '1';
				aux_fil <= i;				
			else
				aux_desborde <= '0';
				aux_fil <= i-'1';
			end if;
			estado_futuro <= st2;

		when st2 =>
			
			if(i = "000000" or j = width) then
				aux_desborde <= '1';
				aux_fil <= i;
				aux_col <= j;				
			else
				aux_desborde <= '0';
				aux_fil <= i-'1';
				aux_col <= j+'1';
			end if;
			estado_futuro <= st3;

		when st3 =>
			
			aux_fil <= i;
			if(j = "000000") then
				aux_desborde <= '1';
				aux_col <= j;				
			else
				aux_desborde <= '0';
				aux_col <= j-'1';
			end if;
			estado_futuro <= st4;

		when st4 =>
			
			aux_desborde <= '0';
			aux_fil <= i;
			aux_col <= j;
			estado_futuro <= st5;

		when st5 =>
			
			aux_fil <= i;
			if(j = width) then
				aux_desborde <= '1';
				aux_col <= j;				
			else
				aux_desborde <= '0';
				aux_col <= j+'1';
			end if;
			estado_futuro <= st6;

		when st6 =>
			
			if(i= lenght or j = "000000") then
				aux_desborde <= '1';
				aux_fil <= i;
				aux_col <= j;				
			else
				aux_desborde <= '0';
				aux_fil <= i+'1';
				aux_col <= j-'1';
			end if;
			estado_futuro <= st7;

		when st7 =>
			
			aux_col <= j;				
			if(i= lenght) then
				aux_desborde <= '1';
				aux_fil <= i;
				
			else
				aux_desborde <= '0';
				aux_fil <= i+'1';
			end if;
			estado_futuro <= st8;

		when st8 =>
			
			if(i = lenght or j = width) then
				aux_desborde <= '1';
				aux_fil <= i;
				aux_col <= j;				
			else
				aux_desborde <= '0';
				aux_fil <= i+'1';
				aux_col <= j+'1';
			end if;
			estado_futuro <= st0;
		
		end case;

end process comb;

sec : process (enable_cnt, asinc_reset, aux_fil, aux_col, aux_desborde)
begin
	if(asinc_reset='1') then
		estado_presente <= st0;
		fila <= (others =>'0');
		columna <= (others =>'0');
		desborde <= '0';
		
	elsif(enable_cnt ='1' and enable_cnt'event) then
		estado_presente <= estado_futuro;
		fila <= aux_fil;
		columna <= aux_col;
		desborde <= aux_desborde;
	end if;

end process sec;

end cnt_arch;