Subversion Repositories uos_processor

-- RAM editor

-- 

library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity ramedit is

        generic(N : integer);

        port(

                        clk : in STD_LOGIC;

                        rst : in STD_LOGIC;

                        btnU : in STD_LOGIC;

                        btnD : in STD_LOGIC;

                        btnL : in STD_LOGIC;

                        btnR : in STD_LOGIC;

                        din : in STD_LOGIC_VECTOR(15 downto 0);

                        we : out STD_LOGIC;

                        address : out STD_LOGIC_VECTOR(N-1 downto 0);

                        data : out STD_LOGIC_VECTOR(7 downto 0)

                );

end ramedit;

architecture Behavioral of ramedit is

        -- Register with the address we currently wish to edit

        signal address_edit : STD_LOGIC_VECTOR(N-1 downto 0);

begin

        process(clk,rst)

        begin

                if rising_edge(clk) then

                        if rst='1' then

                                address_edit<=(others=>'0');

                        else

                                if btnU='1' and btnD='0' then

                                        address_edit <= address_edit+1;

                                elsif btnU='0' and btnD='1' then

                                        address_edit <= address_edit-1;

                                elsif btnL='1' then

                                        address_edit <= din(8+N-1 downto 8);

                                end if;

                        end if;

                end if;

        end process;

        we <= btnR;

        address <= address_edit;

        data <= din(7 downto 0);

end Behavioral;