path: root/de1/fpga-bbc-pq/master/sn76489-fixes.patch

diff --git a/sn76489-1.0/sn76489_comp_pack-p.vhd b/sn76489-1.0/sn76489_comp_pack-p.vhd
index 06b12c8..c5fcc90 100644
--- a/sn76489-1.0/sn76489_comp_pack-p.vhd
+++ b/sn76489-1.0/sn76489_comp_pack-p.vhd
@@ -27,9 +27,11 @@ package sn76489_comp_pack is
       clock_i  : in  std_logic;
       clk_en_i : in  boolean;
       res_n_i  : in  std_logic;
-      we_i     : in  boolean;
+      we_i     : in  std_logic;
       d_i      : in  std_logic_vector(0 to 7);
-      r2_i     : in  std_logic;
+      addr_i   : in  std_logic_vector(0 to 1);
+      rst_a_i  : in  std_logic_vector(0 to 3);
+      rst_cnt_i: in  std_logic_vector(0 to 9);
       ff_o     : out std_logic;
       tone_o   : out signed(0 to 7)
     );
@@ -40,31 +42,14 @@ package sn76489_comp_pack is
       clock_i    : in  std_logic;
       clk_en_i   : in  boolean;
       res_n_i    : in  std_logic;
-      we_i       : in  boolean;
+      we_i       : in  std_logic;
       d_i        : in  std_logic_vector(0 to 7);
-      r2_i       : in  std_logic;
+      addr_i     : in  std_logic_vector(0 to 1);
       tone3_ff_i : in  std_logic;
       noise_o    : out signed(0 to 7)
     );
   end component;
 
-  component sn76489_latch_ctrl
-    port (
-      clock_i    : in  std_logic;
-      clk_en_i   : in  boolean;
-      res_n_i    : in  std_logic;
-      ce_n_i     : in  std_logic;
-      we_n_i     : in  std_logic;
-      d_i        : in  std_logic_vector(0 to 7);
-      ready_o    : out std_logic;
-      tone1_we_o : out boolean;
-      tone2_we_o : out boolean;
-      tone3_we_o : out boolean;
-      noise_we_o : out boolean;
-      r2_o       : out std_logic
-    );
-  end component;
-
   component sn76489_clock_div
     generic (
       clock_div_16_g : integer := 1
diff --git a/sn76489-1.0/sn76489_latch_ctrl-c.vhd b/sn76489-1.0/sn76489_latch_ctrl-c.vhd
deleted file mode 100644
index abc09e0..0000000
--- a/sn76489-1.0/sn76489_latch_ctrl-c.vhd
+++ /dev/null
@@ -1,14 +0,0 @@
--------------------------------------------------------------------------------
---
--- Synthesizable model of TI's SN76489AN.
---
--- $Id: sn76489_latch_ctrl-c.vhd,v 1.2 2005/10/10 22:12:38 arnim Exp $
---
--------------------------------------------------------------------------------
-
-configuration sn76489_latch_ctrl_rtl_c0 of sn76489_latch_ctrl is
-
-  for rtl
-  end for;
-
-end sn76489_latch_ctrl_rtl_c0;
diff --git a/sn76489-1.0/sn76489_latch_ctrl.vhd b/sn76489-1.0/sn76489_latch_ctrl.vhd
deleted file mode 100644
index 789720c..0000000
--- a/sn76489-1.0/sn76489_latch_ctrl.vhd
+++ /dev/null
@@ -1,138 +0,0 @@
--------------------------------------------------------------------------------
---
--- Synthesizable model of TI's SN76489AN.
---
--- $Id: sn76489_latch_ctrl.vhd,v 1.6 2006/02/27 20:30:10 arnim Exp $
---
--- Latch Control Unit
---
--------------------------------------------------------------------------------
---
--- Copyright (c) 2005, 2006, Arnim Laeuger (arnim.laeuger@gmx.net)
---
--- All rights reserved
---
--- Redistribution and use in source and synthezised forms, with or without
--- modification, are permitted provided that the following conditions are met:
---
--- Redistributions of source code must retain the above copyright notice,
--- this list of conditions and the following disclaimer.
---
--- Redistributions in synthesized form must reproduce the above copyright
--- notice, this list of conditions and the following disclaimer in the
--- documentation and/or other materials provided with the distribution.
---
--- Neither the name of the author nor the names of other contributors may
--- be used to endorse or promote products derived from this software without
--- specific prior written permission.
---
--- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
--- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
--- THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
--- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
--- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
--- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
--- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
--- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
--- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
--- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
--- POSSIBILITY OF SUCH DAMAGE.
---
--- Please report bugs to the author, but before you do so, please
--- make sure that this is not a derivative work and that
--- you have the latest version of this file.
---
--------------------------------------------------------------------------------
-
-library ieee;
-use ieee.std_logic_1164.all;
-
-entity sn76489_latch_ctrl is
-
-  port (
-    clock_i    : in  std_logic;
-    clk_en_i   : in  boolean;
-    res_n_i    : in  std_logic;
-    ce_n_i     : in  std_logic;
-    we_n_i     : in  std_logic;
-    d_i        : in  std_logic_vector(0 to 7);
-    ready_o    : out std_logic;
-    tone1_we_o : out boolean;
-    tone2_we_o : out boolean;
-    tone3_we_o : out boolean;
-    noise_we_o : out boolean;
-    r2_o       : out std_logic
-  );
-
-end sn76489_latch_ctrl;
-
-
-library ieee;
-use ieee.numeric_std.all;
-
-architecture rtl of sn76489_latch_ctrl is
-
-  signal reg_q   : std_logic_vector(0 to 2);
-  signal we_q    : boolean;
-  signal ready_q : std_logic;
-
-begin
-
-  -----------------------------------------------------------------------------
-  -- Process seq
-  --
-  -- Purpose:
-  --   Implements the sequential elements.
-  --
-  seq: process (clock_i, res_n_i)
-  begin
-    if res_n_i = '0' then
-      reg_q     <= (others => '0');
-      we_q      <= false;
-      ready_q   <= '0';
-
-    elsif clock_i'event and clock_i = '1' then
-      -- READY Flag Output ----------------------------------------------------
-      if ready_q = '0' and we_q then
-        if clk_en_i then
-          -- assert READY when write access happened
-          ready_q <= '1';
-        end if;
-      elsif ce_n_i = '1' then
-        -- deassert READY when access has finished
-        ready_q <= '0';
-      end if;
-
-      -- Register Selection ---------------------------------------------------
-      if ce_n_i = '0' and we_n_i = '0' then
-        if clk_en_i then
-          if d_i(0) = '1' then
-            reg_q <= d_i(1 to 3);
-          end if;
-          we_q  <= true;
-        end if;
-      else
-        we_q  <= false;
-      end if;
-
-    end if;
-  end process seq;
-  --
-  -----------------------------------------------------------------------------
-
-
-  -----------------------------------------------------------------------------
-  -- Output mapping
-  -----------------------------------------------------------------------------
-  tone1_we_o <= reg_q(0 to 1) = "00" and we_q;
-  tone2_we_o <= reg_q(0 to 1) = "01" and we_q;
-  tone3_we_o <= reg_q(0 to 1) = "10" and we_q;
-  noise_we_o <= reg_q(0 to 1) = "11" and we_q;
-
-  r2_o       <= reg_q(2);
-
-  ready_o    <=   ready_q
-                when ce_n_i = '0' else
-                  '1';
-
-end rtl;
diff --git a/sn76489-1.0/sn76489_noise.vhd b/sn76489-1.0/sn76489_noise.vhd
index 8b2ee0e..035adab 100644
--- a/sn76489-1.0/sn76489_noise.vhd
+++ b/sn76489-1.0/sn76489_noise.vhd
@@ -54,9 +54,9 @@ entity sn76489_noise is
     clock_i    : in  std_logic;
     clk_en_i   : in  boolean;
     res_n_i    : in  std_logic;
-    we_i       : in  boolean;
+    we_i       : in  std_logic;
     d_i        : in  std_logic_vector(0 to 7);
-    r2_i       : in  std_logic;
+    addr_i     : in  std_logic_vector(0 to 1);
     tone3_ff_i : in  std_logic;
     noise_o    : out signed(0 to 7)
   );
@@ -68,6 +68,9 @@ use work.sn76489_comp_pack.sn76489_attenuator;
 
 architecture rtl of sn76489_noise is
 
+  signal selected   : std_logic;
+  signal write_cr   : std_logic;
+
   signal nf_q       : std_logic_vector(0 to 1);
   signal fb_q       : std_logic;
   signal a_q        : std_logic_vector(0 to 3);
@@ -78,12 +81,13 @@ architecture rtl of sn76489_noise is
          shift_source_q    : std_logic;
   signal shift_rise_edge_s : boolean;
 
-  signal lfsr_q            : std_logic_vector(0 to 15);
+  signal lfsr_q            : std_logic_vector(0 to 7);
 
   signal freq_s      : signed(0 to 1);
 
 begin
 
+
   -----------------------------------------------------------------------------
   -- Process cpu_regs
   --
@@ -96,22 +100,25 @@ begin
       nf_q <= (others => '0');
       fb_q <= '0';
       a_q  <= (others => '1');
-
-    elsif clock_i'event and clock_i = '1' then
-      if clk_en_i and we_i then
-        if r2_i = '0' then
-          -- access to control register
-          -- both access types can write to the control register!
-          nf_q <= d_i(6 to 7);
-          fb_q <= d_i(5);
-
-        else
-          -- access to attenuator register
-          -- both access types can write to the attenuator register!
-          a_q <= d_i(4 to 7);
-
+    elsif rising_edge(clock_i) and we_i = '1'  then
+        if d_i(0) = '1' then
+		if d_i(1 to 2) = addr_i then
+		    if d_i(3) = '0' then
+		        selected<='1';
+                        nf_q <= d_i(6 to 7);
+                        fb_q <= d_i(5);
+                    else
+			selected <='0';
+                        a_q <= d_i(4 to 7);
+		    end if;
+		else
+			selected <='0';
+		end if;
+	elsif selected = '1' then
+		selected<='0';
+                nf_q <= d_i(6 to 7);
+                fb_q <= d_i(5);
         end if;
-      end if;
     end if;
   end process cpu_regs;
   --
@@ -130,8 +137,7 @@ begin
       freq_cnt_q <= (others => '0');
       freq_ff_q  <= '0';
 
-    elsif clock_i'event and clock_i = '1' then
-      if clk_en_i then
+    elsif rising_edge(clock_i) and clk_en_i then
         if freq_cnt_q = 0 then
           -- reload frequency counter according to NF setting
           case nf_q is
@@ -152,8 +158,6 @@ begin
           freq_cnt_q <= freq_cnt_q - 1;
 
         end if;
-
-      end if;
     end if;
   end process freq_gen;
   --
@@ -191,6 +195,8 @@ begin
   shift_rise_edge_s <= shift_source_q = '0' and shift_source_s = '1';
 
 
+  write_cr <= '1' when ((we_i='1') and (((d_i(0) = '1') and (d_i(1 to 2) = addr_i) and (d_i(3) = '0')) or (selected='1'))) else '0';
+
   -----------------------------------------------------------------------------
   -- Process lfsr
   --
@@ -219,15 +225,15 @@ begin
       return parity_v;
     end;
 
+
   begin
     if res_n_i = '0' then
       -- reset LFSR to "0000000000000001"
       lfsr_q               <= (others => '0');
       lfsr_q(lfsr_q'right) <= '1';
 
-    elsif clock_i'event and clock_i = '1' then
-      if clk_en_i then
-        if we_i and r2_i = '0' then
+    elsif rising_edge(clock_i) and clk_en_i then
+        if write_cr='1' then
           -- write to noise register
           -- -> reset LFSR
           lfsr_q               <= (others => '0');
@@ -253,7 +259,6 @@ begin
 
         end if;
 
-      end if;
     end if;
   end process lfsr;
   --
diff --git a/sn76489-1.0/sn76489_tone.vhd b/sn76489-1.0/sn76489_tone.vhd
index b71af8b..f1b6885 100644
--- a/sn76489-1.0/sn76489_tone.vhd
+++ b/sn76489-1.0/sn76489_tone.vhd
@@ -54,9 +54,11 @@ entity sn76489_tone is
     clock_i  : in  std_logic;
     clk_en_i : in  boolean;
     res_n_i  : in  std_logic;
-    we_i     : in  boolean;
+    we_i     : in  std_logic;
     d_i      : in  std_logic_vector(0 to 7);
-    r2_i     : in  std_logic;
+    addr_i   : in  std_logic_vector(0 to 1);
+    rst_a_i  : in  std_logic_vector(0 to 3);
+    rst_cnt_i: in  std_logic_vector(0 to 9);
     ff_o     : out std_logic;
     tone_o   : out signed(0 to 7)
   );
@@ -68,6 +70,7 @@ use work.sn76489_comp_pack.sn76489_attenuator;
 
 architecture rtl of sn76489_tone is
 
+  signal selected   : std_logic;
   signal f_q        : std_logic_vector(0 to 9);
   signal a_q        : std_logic_vector(0 to 3);
   signal freq_cnt_q : unsigned(0 to 9);
@@ -75,6 +78,7 @@ architecture rtl of sn76489_tone is
 
   signal freq_s     : signed(0 to 1);
 
+
   function all_zero(a : in std_logic_vector) return boolean is
     variable result_v : boolean;
   begin
@@ -91,6 +95,8 @@ architecture rtl of sn76489_tone is
 
 begin
 
+
+
   -----------------------------------------------------------------------------
   -- Process cpu_regs
   --
@@ -99,27 +105,28 @@ begin
   --
   cpu_regs: process (clock_i, res_n_i)
   begin
-    if res_n_i = '0' then
-      f_q <= (others => '0');
-      a_q <= (others => '1');
-
-    elsif clock_i'event and clock_i = '1' then
-      if clk_en_i and we_i then
-        if r2_i = '0' then
-          -- access to frequency register
-          if d_i(0) = '0' then
-            f_q(0 to 5) <= d_i(2 to 7);
-          else
-            f_q(6 to 9) <= d_i(4 to 7);
-          end if;
-
-        else
-          -- access to attenuator register
-          -- both access types can write to the attenuator register!
-          a_q <= d_i(4 to 7);
 
+    if res_n_i = '0' then
+      f_q <= (others => '1');
+      a_q <= rst_a_i;
+      selected <='0';
+    elsif rising_edge(clock_i) and we_i = '1'  then
+        if d_i(0) = '1' then
+		if d_i(1 to 2) = addr_i then
+		    if d_i(3) = '0' then
+		        selected<='1';
+                        f_q(6 to 9) <= d_i(4 to 7);
+                    else
+			selected <='0';
+                        a_q <= d_i(4 to 7);
+		    end if;
+		else
+			selected <='0';
+		end if;
+	elsif selected = '1' then
+		selected<='0';
+                 f_q(0 to 5) <= d_i(2 to 7);
         end if;
-      end if;
     end if;
   end process cpu_regs;
   --
@@ -135,17 +142,19 @@ begin
   freq_gen: process (clock_i, res_n_i)
   begin
     if res_n_i = '0' then
-      freq_cnt_q <= (others => '0');
+      freq_cnt_q <= unsigned(rst_cnt_i);
       freq_ff_q  <= '0';
 
-    elsif clock_i'event and clock_i = '1' then
-      if clk_en_i then
-        if freq_cnt_q = 0 then
+    elsif rising_edge(clock_i) and clk_en_i then
+        if we_i='1' and selected = '1' then
+          freq_cnt_q <= (others => '0');
+          freq_ff_q <= '1';
+        elsif freq_cnt_q = 0 then
           -- update counter from frequency register
-          freq_cnt_q <= unsigned(f_q);
+          freq_cnt_q <= unsigned(f_q)-to_unsigned(1,10);
 
           -- and toggle the frequency flip-flop if enabled
-          if not all_zero(f_q) then
+	  if  unsigned(f_q) > to_unsigned(1,10) then
             freq_ff_q <= not freq_ff_q;
           else
             -- if frequency setting is 0, then keep flip-flop at +1
@@ -157,7 +166,6 @@ begin
           freq_cnt_q <= freq_cnt_q - 1;
 
         end if;
-      end if;
     end if;
   end process freq_gen;
   --
diff --git a/sn76489-1.0/sn76489_top-c.vhd b/sn76489-1.0/sn76489_top-c.vhd
index 8f709b9..55f3dfb 100644
--- a/sn76489-1.0/sn76489_top-c.vhd
+++ b/sn76489-1.0/sn76489_top-c.vhd
@@ -14,10 +14,6 @@ configuration sn76489_top_struct_c0 of sn76489_top is
       use configuration work.sn76489_clock_div_rtl_c0;
     end for;
 
-    for latch_ctrl_b : sn76489_latch_ctrl
-      use configuration work.sn76489_latch_ctrl_rtl_c0;
-    end for;
-
     for all : sn76489_tone
       use configuration work.sn76489_tone_rtl_c0;
     end for;
diff --git a/sn76489-1.0/sn76489_top.vhd b/sn76489-1.0/sn76489_top.vhd
index deb8170..2f6a01c 100644
--- a/sn76489-1.0/sn76489_top.vhd
+++ b/sn76489-1.0/sn76489_top.vhd
@@ -86,19 +86,17 @@ architecture struct of sn76489_top is
 
   signal clk_en_s    : boolean;
 
-  signal tone1_we_s,
-         tone2_we_s,
-         tone3_we_s,
-         noise_we_s  : boolean;
-  signal r2_s        : std_logic;
-
   signal tone1_s,
          tone2_s,
          tone3_s,
-         noise_s     : signed(0 to 7);
+         noise_s     : signed(0 to 15);
 
   signal tone3_ff_s  : std_logic;
 
+  signal dl : std_logic_vector(0 to 9);
+
+  signal we : std_logic;
+
 begin
 
   -----------------------------------------------------------------------------
@@ -116,26 +114,6 @@ begin
     );
 
 
-  -----------------------------------------------------------------------------
-  -- Latch Control = CPU Interface
-  -----------------------------------------------------------------------------
-  latch_ctrl_b : sn76489_latch_ctrl
-    port map (
-      clock_i    => clock_i,
-      clk_en_i   => clk_en_s,
-      res_n_i    => res_n_i,
-      ce_n_i     => ce_n_i,
-      we_n_i     => we_n_i,
-      d_i        => d_i,
-      ready_o    => ready_o,
-      tone1_we_o => tone1_we_s,
-      tone2_we_o => tone2_we_s,
-      tone3_we_o => tone3_we_s,
-      noise_we_o => noise_we_s,
-      r2_o       => r2_s
-    );
-
-
   -----------------------------------------------------------------------------
   -- Tone Channel 1
   -----------------------------------------------------------------------------
@@ -144,9 +122,11 @@ begin
       clock_i  => clock_i,
       clk_en_i => clk_en_s,
       res_n_i  => res_n_i,
-      we_i     => tone1_we_s,
+      we_i     => we,
       d_i      => d_i,
-      r2_i     => r2_s,
+      addr_i   => "00",
+      rst_a_i  => "0000",
+      rst_cnt_i=> "0000000000",
       ff_o     => open,
       tone_o   => tone1_s
     );
@@ -159,9 +139,11 @@ begin
       clock_i  => clock_i,
       clk_en_i => clk_en_s,
       res_n_i  => res_n_i,
-      we_i     => tone2_we_s,
+      we_i     =>  we,
       d_i      => d_i,
-      r2_i     => r2_s,
+      addr_i   => "01",
+      rst_a_i  => "1000",
+      rst_cnt_i=> "0000110100",
       ff_o     => open,
       tone_o   => tone2_s
     );
@@ -174,9 +156,11 @@ begin
       clock_i  => clock_i,
       clk_en_i => clk_en_s,
       res_n_i  => res_n_i,
-      we_i     => tone3_we_s,
+      we_i     => we,
       d_i      => d_i,
-      r2_i     => r2_s,
+      addr_i   => "10",
+      rst_a_i  => "1000",
+      rst_cnt_i=> "1100110100",
       ff_o     => tone3_ff_s,
       tone_o   => tone3_s
     );
@@ -189,14 +173,16 @@ begin
       clock_i    => clock_i,
       clk_en_i   => clk_en_s,
       res_n_i    => res_n_i,
-      we_i       => noise_we_s,
+      we_i       => we,
       d_i        => d_i,
-      r2_i       => r2_s,
+      addr_i     => "11",
       tone3_ff_i => tone3_ff_s,
       noise_o    => noise_s
     );
 
 
+    we<= not(ce_n_i  or we_n_i) when clk_en_s else '0';
+
 	-- Register output
 	process(clock_i)
 	begin
@@ -207,4 +193,23 @@ begin
 		end if;
 	end process;
 
+	process(clock_i)
+	begin
+		if res_n_i = '0' then
+			dl<=(others => '0');
+		elsif rising_edge(clock_i) then
+			if ce_n_i = '0' and we_n_i = '0'  then
+				if d_i(0)='1' then
+					if d_i(3)='0' then
+						dl(6 to 9) <= d_i(4 to 7);
+					end if;
+				else
+					dl(0 to 5) <= d_i(2 to 7);
+				end if;
+			end if;
+		end if;
+	end process;
+
+	
+        ready_o <= '1';
 end struct;