Implement state machine, arith and I/O instructions now working.

fpga/Makefile

@@ -0,0 +1,14 @@
+CHDL		=	ghdl
+FLAGS		=	--std=08
+STOP		=	9000ns
+
+all:	tb/tb_bfpu.vhd src/bfpu.vhd
+	$(CHDL) -a $(FLAGS) src/alu.vhd src/branch.vhd src/cellMemory.vhd src/instructionMemory.vhd src/memoryPointer.vhd src/programCounter.vhd src/bfpu.vhd tb/tb_bfpu.vhd
+	$(CHDL) -e $(FLAGS) bfpu_tb
+	$(CHDL) -r $(FLAGS) bfpu_tb --wave=bpfu.ghw --stop-time=$(STOP)
+
+clean:
+	find . -name '*.o' -exec rm -r {} \;
+	find . -name '*.cf' -exec rm -r {} \;
+	find . -name '*.ghw' -exec rm -r {} \;
+	find . -name '*_tb' -exec rm -r {} \;

fpga/src/alu.vhd

@@ -36,35 +36,35 @@ begin
                 new_pointer <= std_logic_vector(unsigned(old_pointer) + 1);
 
                 new_cell    <= old_cell;
-                buffer_out  <= "00000000";
+                -- buffer_out  <= "00000000";
             when "001" =>
                 enable_cell <= '0';
                 enable_ptr  <= '1';
                 new_pointer <= std_logic_vector(unsigned(old_pointer) - 1);
 
                 new_cell    <= old_cell;
-                buffer_out  <= "00000000";
+                -- buffer_out  <= "00000000";
             when "010" =>
                 enable_cell <= '1';
                 enable_ptr  <= '0';
                 new_cell    <= std_logic_vector(unsigned(old_cell) + 1);
 
                 new_pointer <= old_pointer;
-                buffer_out  <= "00000000";
+                -- buffer_out  <= "00000000";
             when "011" =>
                 enable_cell <= '1';
                 enable_ptr  <= '0';
                 new_cell    <= std_logic_vector(unsigned(old_cell) - 1);
 
                 new_pointer <= old_pointer;
-                buffer_out  <= "00000000";
+                -- buffer_out  <= "00000000";
             when "100" =>
                 enable_cell <= '1';
                 enable_ptr  <= '0';
                 new_cell    <= extern_in;
 
                 new_pointer <= old_pointer;
-                buffer_out  <= "00000000";
+                -- buffer_out  <= "00000000";
             when "101" =>
                 enable_cell <= '0';
                 enable_ptr  <= '0';
@@ -78,7 +78,7 @@ begin
 
                 new_pointer <= old_pointer;
                 new_cell    <= old_cell;
-                buffer_out  <= "00000000";
+                -- buffer_out  <= "00000000";
         end case;
     end process;
 

fpga/src/bfpu.vhd

@@ -21,7 +21,6 @@ architecture arch of bfpu is
 
     component instructionMemory
         port(
-            clk             :   in  std_logic;
             instructionAddr :   in  std_logic_vector(7 downto 0);
             instruction     :   out std_logic_vector(2 downto 0)
         );
@@ -86,32 +85,58 @@ architecture arch of bfpu is
     end component;
 
     signal s_clk            :   std_logic;
-    signal s_instrAddr      :   std_logic_vector(7 downto 0);
+    signal s_in             :   std_logic_vector(7 downto 0);
-    signal s_instruction    :   std_logic_vector(2 downto 0);
+    signal s_out            :   std_logic_vector(7 downto 0);
 
-    signal s_cell_out       :   std_logic_vector(7 downto 0);
+    signal s_instrAddr      :   std_logic_vector(7 downto 0) := "00000000";
-    signal s_cell_in        :   std_logic_vector(7 downto 0);
+    signal s_instruction    :   std_logic_vector(2 downto 0) := "000";
-    signal s_ptr_out        :   std_logic_vector(15 downto 0);
-    signal s_ptr_in         :   std_logic_vector(15 downto 0);
 
-    signal s_enable_cells   :   std_logic;
+    signal s_cell_out       :   std_logic_vector(7 downto 0) := (others => '0');
-    signal s_enable_ptr     :   std_logic;
+    signal s_cell_in        :   std_logic_vector(7 downto 0) := (others => '0');
+    signal s_ptr_out        :   std_logic_vector(15 downto 0) := (others => '0');
+    signal s_ptr_in         :   std_logic_vector(15 downto 0) := (others => '0');
 
-    signal s_enable_pc      :   std_logic;
+    signal s_enable_cells   :   std_logic := '0';
-    signal s_jmp_pc         :   std_logic;
+    signal s_enable_ptr     :   std_logic := '0';
-    signal s_jmp_addr_pc    :   std_logic_vector(7 downto 0);
 
-    signal s_skip           :   std_logic;
+    signal s_enable_pc      :   std_logic := '1';
-    signal s_enable_cells_o :   std_logic;
+    signal s_jmp_pc         :   std_logic := '0';
-    signal s_enable_ptr_o   :   std_logic;
+    signal s_jmp_addr_pc    :   std_logic_vector(7 downto 0) := "00000000";
+
+    signal s_skip           :   std_logic := '0';
+    signal s_enable_cells_o :   std_logic := '0';
+    signal s_enable_ptr_o   :   std_logic := '0';
+
+    signal processor_state  :   std_logic := '0'; -- 0: execute; 1: write back
 
 begin
 
+    -- clock and state logic
     s_clk <= clk;
+    -- Process state  change state between execute and write back
+    state : process (s_clk) -- runs only, when s_clk changed
+    begin
+        if rising_edge(s_clk) then
+            processor_state <= not processor_state;
+        end if;
+    end process;
+
+    -- Process in_out  set in- and output on clk high and exec/write back
+    in_out : process (s_clk) -- runs only, when s_clk changed
+    begin
+        if rising_edge(s_clk) then
+            if processor_state = '1' then
+                led     <= s_out;
+            else
+                s_in      <= sw;
+            end if;
+        end if;
+    end process;
+
+
 
     instrMemory : instructionMemory
     port map(
-        clk => s_clk,
         instructionAddr => s_instrAddr,
         instruction => s_instruction
     );
@@ -121,13 +146,13 @@ begin
         instruction	=>	s_instruction,
         old_cell	=>	s_cell_out,
         old_pointer =>	s_ptr_out,
-        extern_in	=>	sw,
+        extern_in	=>	s_in,
 
         new_cell	=>	s_cell_in,
         new_pointer	=>	s_ptr_in,
         enable_cell	=>	s_enable_cells_o,
         enable_ptr	=>	s_enable_ptr_o,
-        extern_out	=>  led
+        extern_out	=>  s_out
     );
 
     ptr_bf : ptr
@@ -150,7 +175,7 @@ begin
     pc : program_counter
     port map(
         clk     => s_clk,
-        enable  => s_enable_pc,
+        enable  => s_enable_pc and processor_state,
         jmp     => s_jmp_pc,
         pc_in   => s_jmp_addr_pc,
         pc_out  => s_instrAddr
@@ -168,8 +193,8 @@ begin
         pc_out      => s_jmp_addr_pc
     );
 
-    s_enable_ptr    <= s_skip and s_enable_ptr_o;
+    s_enable_ptr    <= not s_skip and s_enable_ptr_o and processor_state;
-    s_enable_cells  <= s_skip and s_enable_cells_o;
+    s_enable_cells  <= not s_skip and s_enable_cells_o and processor_state;
     debug           <= s_cell_out;
 
 end arch;

fpga/src/branch.vhd

@@ -31,6 +31,7 @@ architecture impl of branch is
     signal nested           : std_logic_vector(7 downto 0) := (others => '0'); -- count nested loops
     signal skip_internal    : std_logic := '0';
     signal stack_ptr        : std_logic_vector(7 downto 0) := (others => '0');
+    signal pc_enable_internal : std_logic := '1';
 
 begin
 
@@ -38,61 +39,55 @@ begin
     p_branch : process (clk, skip_internal, instruction, cell_value)
     begin
         if rising_edge(clk) then
+
             if instruction = "110" and unsigned(cell_value) = 0 and unsigned(nested) = 0 and skip_internal = '0' then
                 skip_internal <= '1';
             end if;
-        end if;
 
             -- set skip to false
-        if rising_edge(clk) then
             if instruction = "111" and unsigned(nested) = 0 and skip_internal = '1' then
                 skip_internal <= '0';
             end if;
-        end if;
 
             -- Process p_nest : raise nest by one as [ is passed
-        if rising_edge(clk) then
             if instruction = "110" and skip_internal = '1' then
                 nested <= std_logic_vector(unsigned(nested) + 1);
             end if;
-        end if;
 
             -- Process p_unnest : lower nest, as ] is passed
-        if rising_edge(clk) then
             if instruction = "111" and unsigned(nested) > 0 and skip_internal = '1' then
                 nested <= std_logic_vector(unsigned(nested) - 1);
             end if;
-        end if;
 
             -- Process p_push : raise stack and push address
-        if rising_edge(clk) and instruction = "110" and unsigned(cell_value) > 0 and skip_internal = '0' then
+            if instruction = "110" and unsigned(cell_value) > 0 and skip_internal = '0' then
-            if pc_enable = '0' then
+
+                if pc_enable_internal = '0' then
                     -- restore push_state and push address
                     addr_stack(to_integer(unsigned(stack_ptr))) <= instr_addr;
-                pc_enable <= '1';
+                    pc_enable_internal <= '1';
                 else
                     -- raise stack, disable pc and unset push_state
                     stack_ptr <= std_logic_vector(unsigned(stack_ptr) + 1);
-                pc_enable <= '0';
+                    pc_enable_internal <= '0';
                 end if;
             end if;
 
             -- Process p_pop : read address to jump address and lower stack
-        if rising_edge(clk) and instruction = "111" and unsigned(cell_value) > 0 and skip_internal = '0' then
+            if instruction = "111" and unsigned(cell_value) > 0 and skip_internal = '1' then
-            if pc_enable = '0' then
+                if pc_enable_internal = '0' then
                     -- set address to pc_out, disable pc and unset push_state
-                pc_out <= addr_stack(to_integer(unsigned(stack_ptr)));
+                    -- pc_out <= addr_stack(to_integer(unsigned(stack_ptr))); TODO: restore if error with continuous assignment
-                pc_enable <= '1';
+                    pc_enable_internal <= '1';
                 else
                     -- set pc to enabled, restore push_state and lower stack
-                pc_enable <= '0';
+                    pc_enable_internal <= '0';
                     stack_ptr <= std_logic_vector(unsigned(stack_ptr) - 1);
                 end if;
             end if;
 
             -- regulate jump
-        if rising_edge(clk) then
+            if instruction = "111" and unsigned(cell_value) > 0 and skip_internal = '0' and pc_enable_internal = '1' then
-            if instruction = "111" and unsigned(cell_value) > 0 and skip_internal = '0' and pc_enable = '1' then
                 jump <= '1';
             else
                 jump <= '0';
@@ -101,5 +96,7 @@ begin
     end process;
 
     skip        <=  skip_internal;
+    pc_enable   <=  pc_enable_internal;
+    pc_out      <= addr_stack(to_integer(unsigned(stack_ptr)));
 
 end impl;

fpga/src/instructionMemory.vhd

@@ -10,7 +10,6 @@ use ieee.numeric_std.all;
 entity instructionMemory is
 
     port(
-        clk                 :   in  std_logic;      -- clock with speed of board clock; Read on clock cycle
         instructionAddr     :   in  std_logic_vector(7 downto 0); -- We start with 256 instructions
 
         instruction         :   out std_logic_vector(2 downto 0)  -- instruction in current cell
@@ -21,18 +20,20 @@ end instructionMemory;
 architecture arch of instructionMemory is
 
     type imem is array(0 to 255) of std_logic_vector(2 downto 0);
-    -- [+.]
+    -- ,>+<.>.
-    signal memory : imem := (b"110", b"010", b"101", b"111", others => "000");
+    signal memory : imem := (b"100", b"000", b"010", b"001", b"101", b"000", b"101", others => "000");
 begin
     -- Process clk_read
-    clk_read : process (clk) -- runs only, when clk changed
+--    clk_read : process (clk) -- runs only, when clk changed
-    begin
+--    begin
-
+--
-        if rising_edge(clk) then
+--        if rising_edge(clk) then
+--
+--            instruction <= memory(to_integer(unsigned(instructionAddr)));
+--
+--        end if;
+--    end process;
 
     instruction <= memory(to_integer(unsigned(instructionAddr)));
 
-        end if;
-    end process;
-
 end arch;

fpga/src/memoryPointer.vhd

@@ -19,7 +19,7 @@ end ptr;
 
 -- Architecture implement_ptr of ptr:
 architecture implement_ptr of ptr is
-    signal reg : std_logic_vector(15 downto 0);
+    signal reg : std_logic_vector(15 downto 0) := (others => '0');
 begin
 
     -- Process Write  set new_ptr

fpga/src/programCounter.vhd

@@ -23,7 +23,7 @@ architecture pc of program_counter is
 begin
 
     -- Process count
-    count : process (clk, enable) -- runs only, when clk, enable, jmp changed
+    count : process (clk, enable, jmp) -- runs only, when clk, enable, jmp changed
     begin
         if rising_edge(clk) and enable = '1' then
             if jmp = '1' then

fpga/tb/tb_bfpu.vhd

@@ -28,13 +28,15 @@ architecture implementation of bfpu_tb is
 
 begin
 
-    uut : entity bfpu
+    uut : entity work.bfpu(arch)
         port map (
             clk     =>  clk,
             sw      =>  sw,
             debug   =>  debug,
             led     =>  led);
 
+    sw      <= "00110011";
+
     -- Clock process definitions
     clk_process :   process
     begin