Reading/writing data to/from files into 2D array

Hi:

I need to verify my design by comparing the VHDL simulation results
with actual results.I'm working with images and so,the input data is a
text file obtained from Matlab.The text file has image data (of image
size ... 256x256).I tried to read the data from the file into a 2D
array. The data has to be in the form of a matrix (2D array),as I need
to perform block processing later. Below is the code I'm working on.I
would highly appreciate any help/suggestions in doing this.

library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_arith.all;
use IEEE.std_logic_unsigned.all;
use IEEE.numeric_std.all;
use work.data.all;

entity PE is

port (search_data1_in : in data_array;
current_data1_in : in data_array;
clk,reset : in std_logic;
SAD_blk : out std_logic_vector(11 downto 0)
);
end PE ;

architecture BEHAVE of PE is

signal search_data_in,search_data1_in1 : data_array;
signal current_data1_in1,current_data_in: data_array;
signal s_ras,s_cas,c_ras,c_cas : std_logic;
signal s_row,s_col,c_row,c_col : integer;
signal s_address,c_address : std_logic_vector(15 downto 0);

type integer_file is file of integer;
file data_in : integer_file is in "data.txt";

component S_DRAM
port(s_address : in std_logic_vector(15 downto 0);
clk,reset : in std_logic;
s_we : in std_logic;
s_ras,s_cas : in std_logic;
s_row,s_col : out integer;
search_data_in : in data_array;
search_data_out : out data_array
);
end component;

begin

DRAM_S : S_DRAM port map(s_address => s_address, clk => clk, reset
=> reset, s_we => s_we, s_ras => s_ras, s_cas => s_cas, s_row =>
s_row, s_col => s_col, search_data_in => search_data_in,
search_data_out => search_data1_in1);

process
type Y_array is array (1 to 2,1 to 2) of integer;
variable Y : Y_array;
begin
while not endfile (data_in) loop
for i in 1 to 2 loop
for j in 1 to 2 loop
read(data_in,Y(i,j));
end loop;
end loop;
end loop;
wait for 2 ns;
end process;

end behave;

Also,I need divide this 256x256 matrix into 4x4 blocks.I'm not
sure,where to start on this.Please give me some ideas to implement
this.

Thanks a lot,
Modukuri

Modukuri