arraystypesvhdldimensional

pass a dimentional array(2D) to a function VHDL


I declared a matrix and a signal in my TOP file like this:

type scanImage is array (0 to 7,0 to 7) of std_logic_vector(2 downto 0);
signal image_matrix : scanImage;

Now, I want to send the above signal to a function which calculates number of cells in the matrix which are not "000".

My package looks like this:


library IEEE;
use IEEE.std_logic_1164.all;
 use IEEE.std_logic_unsigned.all;
 use IEEE.std_logic_arith.all;
use IEEE.NUMERIC_STD.ALL;
 USE IEEE.NUMERIC_BIT.ALL;


PACKAGE my_pack IS

type double_array is array (0 to 7,0 to 7) of std_logic_vector(2 downto 0);

--------------------square calculation declaration--------------------------
 function square_calculation(matrix : double_array) return integer;


 ---------------------------------------------------------------------
 function square_calculation(matrix : double_array) return integer IS
 variable tmp: integer range 0 to 64;
 begin
  tmp:=0;
  for i in 0 to 7 loop

            for j in 0 to 7 loop
                if matrix(i,j)/="000" then
                    tmp:=tmp+1;
                end if;
            end loop;

end loop;
return tmp;

end function square_calculation;


 END my_pack;

After compilizing I get this error: Error (10476): VHDL error at vision_ctrl.vhd(112): type of identifier "image_matrix" does not agree with its usage as "double_array" type

Thanks for helping me.


Solution

  • The two arrays scanImage and double_array are not the same type; just happens to be declared the same way.

    So declare image_matrix with the type double_array, instead of making a new type scanImage:

    signal image_matrix : my_pack.double_array;
    

    Then you can use my_pack.square_calculation with the image_matrix argument.