Subversion Repositories keyboardcontroller

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

use work.Constants.all;

entity FSM is

    port (reset, clk : in  std_logic;

                strobe : out std_logic;

                sample : out std_logic;

                analyse : out std_logic;

                store : out std_logic;

                produce : out std_logic;

                release : out std_logic;

                debounced : in std_logic;

                keychanged : in std_logic; --keychange found

                keyreleased : in std_logic

        );

end FSM;

architecture FSM_arc of FSM is

    signal nState, cState : states;

begin

    process

    begin

    wait until rising_edge(clk);

           if( reset = '1' ) then

            cState <= idle;

           else

            cState <= nState;

           end if;

    end process;

    process(cState, debounced, keychanged, keyreleased)

    begin

                case cState is

                when idle =>                                            nState <= strobing;

                when strobing =>                                        nState <= sampling;

                when sampling =>                                        nState <= analysing;

                when analysing =>                                       if (debounced='1') then

                                                                                                        nState <= storing;

                                                                                                else

                                                                                                        nState <= analysing;

                                                                                                end if;

                when storing =>                          nState <= storing_stage2;

                when storing_stage2 => if (keychanged='1' and keyreleased='0') then

                                                                                                        nState <= producenormal;

                                                                                                elsif(keychanged='1' and keyreleased='1') then

                                                                                                        nState <= producerelease;

                                                                                                elsif (keychanged='0') then

                                                                                                        nState <= strobing;

                                                                                                end if;

                when producenormal =>                   nState <= strobing;

                when producerelease =>                  nState <= strobing;

                when others =>                                  nState <= idle;

      end case;

        end process;

        strobe <= cState(6);

        sample <= cState(5);

        analyse <= cState(4);

        store <= cState(3);

        produce <= cState(2);

        release <= cState(1);

        end FSM_arc;