150 lines
3.9 KiB
VHDL
150 lines
3.9 KiB
VHDL
library ieee;
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use ieee.std_logic_1164.all;
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use ieee.numeric_std.all;
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entity control_logic is
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end control_logic;
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architecture test of control_logic is
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component main
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generic (
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FIRST: boolean
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);
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port (
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func: in std_logic_vector(3 downto 0);
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accu: in std_logic_vector(7 downto 0);
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ram: in std_logic_vector(7 downto 0);
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carry_in: in std_logic;
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result: out std_logic_vector(7 downto 0);
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carry_out: out std_logic
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);
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end component;
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type ram_type is array(0 to 4095) of std_logic_vector(15 downto 0);
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signal clk: std_logic;
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signal first: boolean := false;
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signal acc: std_logic_vector(15 downto 0) := (others => '0');
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signal ir: std_logic_vector(15 downto 0) := (others => '0');
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signal ram: ram_type := (
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0 => "0001000000001010",
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1 => "0011000000001000",
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2 => "0000000000001010",
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3 => "1011000000000000",
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4 => "0010000000000000",
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5 => "0000000000000000",
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6 => "0000000000000101",
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7 => "0000000000000111",
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8 => "0001001110001000",
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9 => "0000000000000000",
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10 => "0000000000000000",
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others => (others => '0')
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);
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signal pc: std_logic_vector(11 downto 0) := (others => '0');
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signal data_out: std_logic_vector(15 downto 0);
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signal data_in: std_logic_vector(15 downto 0);
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signal carry_propagation: std_logic;
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signal addr: std_logic_vector(11 downto 0);
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signal op: std_logic_vector(3 downto 0);
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signal write_ram: std_logic;
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signal write_pc: std_logic;
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signal inc_pc: std_logic;
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signal ram_addr_ir: std_logic;
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signal write_ir: std_logic;
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signal write_acc: std_logic;
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begin
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op <= ir(15 downto 12);
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addr <= ir(11 downto 0) when ram_addr_ir = '1' else pc;
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data_out <= ram(to_integer(unsigned(addr)));
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alu1: main generic map (
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FIRST => true
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) port map (
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func => op,
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accu => acc(7 downto 0),
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ram => data_out(7 downto 0),
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carry_in => '0',
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result => data_in(7 downto 0),
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carry_out => carry_propagation
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);
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alu2: main generic map (
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FIRST => false
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) port map (
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func => op,
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accu => acc(15 downto 8),
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ram => data_out(15 downto 8),
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carry_in => carry_propagation,
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result => data_in(15 downto 8),
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carry_out => open
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);
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process(clk)
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begin
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if rising_edge(clk) then
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if write_acc = '1' then
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acc <= data_in;
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end if;
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if write_ir = '1' then
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ir <= data_out;
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end if;
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if write_ram = '1' then
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ram(to_integer(unsigned(addr))) <= data_in;
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end if;
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if write_pc = '1' then
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pc <= ir(11 downto 0);
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elsif inc_pc = '1' then
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pc <= std_logic_vector(unsigned(pc) + 1);
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end if;
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end if;
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end process;
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process(first, op, acc)
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begin
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write_ram <= '0';
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write_pc <= '0';
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inc_pc <= '0';
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ram_addr_ir <= '1';
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write_ir <= '0';
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write_acc <= '1';
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if first then
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if op = "0000" then
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write_ram <= '1';
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end if;
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if acc = "0000000000000000" and op = "0010" then
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write_pc <= '1';
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end if;
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if op = "0000" or op = "0010" or op(3 downto 2) = "11" then
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write_acc <= '0';
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end if;
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else
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inc_pc <= '1';
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ram_addr_ir <= '0';
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write_ir <= '1';
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write_acc <= '0';
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end if;
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end process;
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process(clk)
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begin
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if rising_edge(clk) then
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first <= not first;
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end if;
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end process;
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process
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begin
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clk <= '1';
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wait for 1us;
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clk <= '0';
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wait for 1us;
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end process;
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end test;
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