library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

entity ram_top is
    port (
        CLOCK_50 : in  std_logic;
        KEY      : in  std_logic_vector(3 downto 0);  -- KEY3 не используется, KEY2/1/0
        SW       : in  std_logic_vector(0 downto 0);  -- SW0: write enable
        HEX7     : out std_logic_vector(6 downto 0);  -- адрес: старший разряд (десятичный)
        HEX6     : out std_logic_vector(6 downto 0);  -- адрес: младший разряд (десятичный)
        HEX5     : out std_logic_vector(6 downto 0);  -- данные: старший nibble (hex)
        HEX4     : out std_logic_vector(6 downto 0);  -- данные: младший nibble (hex)
        HEX3     : out std_logic_vector(6 downto 0);  -- чтение: старший nibble (hex)
        HEX2     : out std_logic_vector(6 downto 0)   -- чтение: младший nibble (hex)
    );
end ram_top;

architecture behavior of ram_top is

    -- Компонент RAM (библиотечный модуль)
    component ram_module
        port (
            clock   : in  std_logic;
            wren    : in  std_logic;
            address : in  std_logic_vector(4 downto 0);
            data    : in  std_logic_vector(7 downto 0);
            q       : out std_logic_vector(7 downto 0)
        );
    end component;

    -- Счетчики
    signal addr_counter : unsigned(4 downto 0) := (others => '0');  -- адрес 0-31
    signal data_counter : unsigned(7 downto 0) := (others => '0');  -- данные 0-255
    signal ram_data_in  : std_logic_vector(7 downto 0);             -- вход RAM
    signal ram_data_out : std_logic_vector(7 downto 0);             -- выход RAM
    signal ram_wren     : std_logic;                                -- разрешение записи
    
    -- Синхронизация кнопок
    signal key_sync1 : std_logic_vector(1 downto 0);  -- KEY1 (data+)
    signal key_sync2 : std_logic_vector(1 downto 0);  -- KEY2 (addr+)
    signal key_sync0 : std_logic_vector(1 downto 0);  -- KEY0 (clock)
    
    -- Обнаружение нажатий
    signal key1_press : std_logic;  -- data increment
    signal key2_press : std_logic;  -- addr increment
    signal key0_press : std_logic;  -- RAM clock pulse

begin

    -- Синхронизация кнопок
    process(CLOCK_50)
    begin
        if rising_edge(CLOCK_50) then
            key_sync1 <= key_sync1(0) & KEY(1);
            key_sync2 <= key_sync2(0) & KEY(2);
            key_sync0 <= key_sync0(0) & KEY(0);
        end if;
    end process;

    -- Детекция нажатий (спадний фронт)
    key1_press <= '1' when key_sync1(1) = '1' and key_sync1(0) = '0' else '0';
    key2_press <= '1' when key_sync2(1) = '1' and key_sync2(0) = '0' else '0';
    key0_press <= '1' when key_sync0(1) = '1' and key_sync0(0) = '0' else '0';

    -- Счетчики адреса и данных
    process(CLOCK_50)
    begin
        if rising_edge(CLOCK_50) then
            if key2_press = '1' then
                addr_counter <= addr_counter + 1;  -- адрес 0->1->...->31->0
            end if;
            
            if key1_press = '1' then
                data_counter <= data_counter + 1;  -- данные 0->1->...->255->0
            end if;
        end if;
    end process;

    -- Подготовка данных для RAM
    ram_data_in <= std_logic_vector(data_counter);
    ram_wren    <= SW(0) and key0_press;  -- запись только при SW0=1 И KEY0

    -- RAM модуль
    ram_inst : ram_module
        port map (
            clock   => CLOCK_50,
            wren    => ram_wren,
            address => std_logic_vector(addr_counter),
            data    => ram_data_in,
            q       => ram_data_out
        );

    -- ОТображение АДРЕСА в ДЕСЯТИЧНОМ виде (HEX7+HEX6)
    -- addr_counter[4:0] -> десятки + единицы (0-31)
    process(addr_counter)
        variable tens, units : unsigned(3 downto 0);
    begin
        tens  := addr_counter / 10;  -- десятки (0-3)
        units := addr_counter mod 10; -- единицы (0-9)
        
        -- HEX7: десятки (0-3)
        case tens is
            when "0000" => HEX7 <= "1000000"; -- 0
            when "0001" => HEX7 <= "1111001"; -- 1
            when "0010" => HEX7 <= "0100100"; -- 2
            when "0011" => HEX7 <= "0110000"; -- 3
            when others => HEX7 <= "1111111";
        end case;
        
        -- HEX6: единицы (0-9)
        case units is
            when "0000" => HEX6 <= "1000000"; -- 0
            when "0001" => HEX6 <= "1111001"; -- 1
            when "0010" => HEX6 <= "0100100"; -- 2
            when "0011" => HEX6 <= "0110000"; -- 3
            when "0100" => HEX6 <= "0011001"; -- 4
            when "0101" => HEX6 <= "0010010"; -- 5
            when "0110" => HEX6 <= "0000010"; -- 6
            when "0111" => HEX6 <= "1111000"; -- 7
            when "1000" => HEX6 <= "0000000"; -- 8
            when "1001" => HEX6 <= "0010000"; -- 9
            when others => HEX6 <= "1111111";
        end case;
    end process;

    -- ОТображение ДАННЫХ ВВОДА в HEX (HEX5+HEX4)
    process(data_counter)
    begin
        -- HEX5: старший nibble (0-F)
        case data_counter(7 downto 4) is
            when "0000" => HEX5 <= "1000000"; -- 0
            when "0001" => HEX5 <= "1111001"; -- 1
            when "0010" => HEX5 <= "0100100"; -- 2
            when "0011" => HEX5 <= "0110000"; -- 3
            when "0100" => HEX5 <= "0011001"; -- 4
            when "0101" => HEX5 <= "0010010"; -- 5
            when "0110" => HEX5 <= "0000010"; -- 6
            when "0111" => HEX5 <= "1111000"; -- 7
            when "1000" => HEX5 <= "0000000"; -- 8
            when "1001" => HEX5 <= "0010000"; -- 9
            when "1010" => HEX5 <= "0001000"; -- A
            when "1011" => HEX5 <= "0000011"; -- b
            when "1100" => HEX5 <= "1000110"; -- C
            when "1101" => HEX5 <= "0100001"; -- d
            when "1110" => HEX5 <= "0000110"; -- E
            when "1111" => HEX5 <= "0001111"; -- F
            when others => HEX5 <= "1111111";
        end case;
        
        -- HEX4: младший nibble (0-F)
        case data_counter(3 downto 0) is
            when "0000" => HEX4 <= "1000000"; -- 0
            when "0001" => HEX4 <= "1111001"; -- 1
            when "0010" => HEX4 <= "0100100"; -- 2
            when "0011" => HEX4 <= "0110000"; -- 3
            when "0100" => HEX4 <= "0011001"; -- 4
            when "0101" => HEX4 <= "0010010"; -- 5
            when "0110" => HEX4 <= "0000010"; -- 6
            when "0111" => HEX4 <= "1111000"; -- 7
            when "1000" => HEX4 <= "0000000"; -- 8
            when "1001" => HEX4 <= "0010000"; -- 9
            when "1010" => HEX4 <= "0001000"; -- A
            when "1011" => HEX4 <= "0000011"; -- b
            when "1100" => HEX4 <= "1000110"; -- C
            when "1101" => HEX4 <= "0100001"; -- d
            when "1110" => HEX4 <= "0000110"; -- E
            when "1111" => HEX4 <= "0001111"; -- F
            when others => HEX4 <= "1111111";
        end case;
    end process;

    -- ОТображение ДАННЫХ ЧТЕНИЯ из RAM в HEX (HEX3+HEX2)
    process(ram_data_out)
    begin
        -- HEX3: старший nibble
        case ram_data_out(7 downto 4) is
            when "0000" => HEX3 <= "1000000"; -- 0
            when "0001" => HEX3 <= "1111001"; -- 1
            when "0010" => HEX3 <= "0100100"; -- 2
            when "0011" => HEX3 <= "0110000"; -- 3
            when "0100" => HEX3 <= "0011001"; -- 4
            when "0101" => HEX3 <= "0010010"; -- 5
            when "0110" => HEX3 <= "0000010"; -- 6
            when "0111" => HEX3 <= "1111000"; -- 7
            when "1000" => HEX3 <= "0000000"; -- 8
            when "1001" => HEX3 <= "0010000"; -- 9
            when "1010" => HEX3 <= "0001000"; -- A
            when "1011" => HEX3 <= "0000011"; -- b
            when "1100" => HEX3 <= "1000110"; -- C
            when "1101" => HEX3 <= "0100001"; -- d
            when "1110" => HEX3 <= "0000110"; -- E
            when "1111" => HEX3 <= "0001111"; -- F
            when others => HEX3 <= "1111111";
        end case;
        
        -- HEX2: младший nibble
        case ram_data_out(3 downto 0) is
            when "0000" => HEX2 <= "1000000"; -- 0
            when "0001" => HEX2 <= "1111001"; -- 1
            when "0010" => HEX2 <= "0100100"; -- 2
            when "0011" => HEX2 <= "0110000"; -- 3
            when "0100" => HEX2 <= "0011001"; -- 4
            when "0101" => HEX2 <= "0010010"; -- 5
            when "0110" => HEX2 <= "0000010"; -- 6
            when "0111" => HEX2 <= "1111000"; -- 7
            when "1000" => HEX2 <= "0000000"; -- 8
            when "1001" => HEX2 <= "0010000"; -- 9
            when "1010" => HEX2 <= "0001000"; -- A
            when "1011" => HEX2 <= "0000011"; -- b
            when "1100" => HEX2 <= "1000110"; -- C
            when "1101" => HEX2 <= "0100001"; -- d
            when "1110" => HEX2 <= "0000110"; -- E
            when "1111" => HEX2 <= "0001111"; -- F
            when others => HEX2 <= "1111111";
        end case;
    end process;

end behavior;