Subversion Repositories keyboardcontroller

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

use work.Constants.all;

entity Strober is

    port (reset, clk : in  std_logic;

       strobe : in std_logic;

       sample : in std_logic;

       env_col : in col;

       env_row : out row;

       sample_col : out col; --rows and cols to be analysed

       sample_row_number : out row_number

       );

end Strober;

architecture Strober_arc of Strober is

function decode_row(inp: row_number) return row is

variable rowstrobe : row;

begin

        case inp is

        when 11 => rowstrobe := "011111111111";

        when 10 => rowstrobe := "101111111111";

        when 9 => rowstrobe :=  "110111111111";

        when 8 => rowstrobe :=  "111011111111";

        when 7 => rowstrobe :=  "111101111111";

        when 6 => rowstrobe :=  "111110111111";

        when 5 => rowstrobe :=  "111111011111";

        when 4 => rowstrobe :=  "111111101111";

        when 3 => rowstrobe :=  "111111110111";

        when 2 => rowstrobe :=  "111111111011";

        when 1 => rowstrobe :=  "111111111101";

        when 0 => rowstrobe :=  "111111111110";

        when others => rowstrobe := "111111111111";

        end case;

        return rowstrobe;

end decode_row;

begin

   strober: process

   variable row_counter : integer;

   begin

       wait until rising_edge(clk);

       if (reset = '1') then

           env_row <= "111111111111";

           row_counter := 0;

       elsif (strobe = '1') then

           if (row_counter < number_of_cols-1) then

                row_counter := row_counter + 1;

           elsif(row_counter = number_of_cols-1)then

                row_counter := 0;

           end if;

           env_row <= decode_row(row_counter);

       elsif (sample ='1') then --first sample

           sample_row_number <= row_counter;

           sample_col <= not env_col;

       end if;

   end process;

end strober_arc;