Ad test bench for the computer control logic

2018-05-31 22:31:15 +02:00
parent 611e0ac388
commit e1a3ab745c
2 changed files with 165 additions and 12 deletions
--- a/firmware/alu/tests/control_logic.vhd
+++ b/firmware/alu/tests/control_logic.vhd
@ -0,0 +1,149 @@
+library ieee;
+
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+
+entity control_logic is
+end control_logic;
+
+architecture test of control_logic is
+    component main
+        generic (
+            FIRST: boolean
+        );
+        port (
+            func: in std_logic_vector(3 downto 0);
+            accu: in std_logic_vector(7 downto 0);
+            ram: in std_logic_vector(7 downto 0);
+            carry_in: in std_logic;
+            result: out std_logic_vector(7 downto 0);
+            carry_out: out std_logic
+        );
+    end component;
+
+    type ram_type is array(0 to 4095) of std_logic_vector(15 downto 0);
+
+    signal clk: std_logic;
+    signal first: boolean := false;
+
+    signal acc: std_logic_vector(15 downto 0) := (others => '0');
+    signal ir: std_logic_vector(15 downto 0) := (others => '0');
+    signal ram: ram_type := (
+         0 => "0001000000001010",
+         1 => "0011000000001000",
+         2 => "0000000000001010",
+         3 => "1011000000000000",
+         4 => "0010000000000000",
+         5 => "0000000000000000",
+         6 => "0000000000000101",
+         7 => "0000000000000111",
+         8 => "0001001110001000",
+         9 => "0000000000000000",
+        10 => "0000000000000000",
+        others => (others => '0')
+    );
+    signal pc:  std_logic_vector(11 downto 0) := (others => '0');
+
+    signal data_out: std_logic_vector(15 downto 0);
+    signal data_in: std_logic_vector(15 downto 0);
+    signal carry_propagation: std_logic;
+    signal addr: std_logic_vector(11 downto 0);
+    signal op: std_logic_vector(3 downto 0);
+
+    signal write_ram: std_logic;
+    signal write_pc: std_logic;
+    signal inc_pc: std_logic;
+    signal ram_addr_ir: std_logic;
+    signal write_ir: std_logic;
+    signal write_acc: std_logic;
+
+
+begin
+    op <= ir(15 downto 12);
+    addr <= ir(11 downto 0) when ram_addr_ir = '1' else pc;
+    data_out <= ram(to_integer(unsigned(addr)));
+
+    alu1: main generic map (
+        FIRST => true
+    ) port map (
+        func => op,
+        accu => acc(7 downto 0),
+        ram => data_out(7 downto 0),
+        carry_in => '0',
+        result => data_in(7 downto 0),
+        carry_out => carry_propagation
+    );
+
+    alu2: main generic map (
+        FIRST => false
+    ) port map (
+        func => op,
+        accu => acc(15 downto 8),
+        ram => data_out(15 downto 8),
+        carry_in => carry_propagation,
+        result => data_in(15 downto 8),
+        carry_out => open
+    );
+
+    process(clk)
+    begin
+        if rising_edge(clk) then
+            if write_acc = '1' then
+                acc <= data_in;
+            end if;
+            if write_ir = '1' then
+                ir <= data_out;
+            end if;
+            if write_ram = '1' then
+                ram(to_integer(unsigned(addr))) <= data_in;
+            end if;
+            if write_pc = '1' then
+                pc <= ir(11 downto 0);
+            elsif inc_pc = '1' then
+                pc <= std_logic_vector(unsigned(pc) + 1);
+            end if;
+        end if;
+    end process;
+
+    process(first, op, acc)
+    begin
+        write_ram <= '0';
+        write_pc <= '0';
+        inc_pc <= '0';
+        ram_addr_ir <= '1';
+        write_ir <= '0';
+        write_acc <= '1';
+
+        if first then
+            if op = "0000" then
+                write_ram <= '1';
+            end if;
+            if acc = "0000000000000000" and op = "0010" then
+                write_pc <= '1';
+            end if;
+            if op = "0000" or op = "0010" or op(3 downto 2) = "11" then
+                write_acc <= '0';
+            end if;
+        else
+            inc_pc <= '1';
+            ram_addr_ir <= '0';
+            write_ir <= '1';
+            write_acc <= '0';
+        end if;
+    end process;
+
+    process(clk)
+    begin
+        if rising_edge(clk) then
+            first <= not first;
+        end if;
+    end process;
+
+    process
+    begin
+        clk <= '1';
+        wait for 1us;
+        clk <= '0';
+        wait for 1us;
+    end process;
+end test;