Delete dac.vhd

Arcade_MiST/Atari Centipede Hardware/Centipede_MiST/rtl/dac.vhd

@@ -1,71 +0,0 @@
--------------------------------------------------------------------------------
---
--- Delta-Sigma DAC
---
--- $Id: dac.vhd,v 1.1 2005/10/25 21:09:42 arnim Exp $
---
--- Refer to Xilinx Application Note XAPP154.
---
--- This DAC requires an external RC low-pass filter:
---
---   dac_o 0---XXXXX---+---0 analog audio
---              3k3    |
---                    === 4n7
---                     |
---                    GND
---
--------------------------------------------------------------------------------
-
-library ieee;
-use ieee.std_logic_1164.all;
-
-entity dac is
-
-  generic (
-    msbi_g : integer := 15
-  );
-  port (
-    clk_i   : in  std_logic;
-    res_n_i : in  std_logic;
-    dac_i   : in  std_logic_vector(msbi_g downto 0);
-    dac_o   : out std_logic
-  );
-
-end dac;
-
-library ieee;
-use ieee.numeric_std.all;
-
-architecture rtl of dac is
-
-  signal DACout_q      : std_logic;
-  signal DeltaAdder_s,
-         SigmaAdder_s,
-         SigmaLatch_q,
-         DeltaB_s      : unsigned(msbi_g+2 downto 0);
-
-begin
-
-  DeltaB_s(msbi_g+2 downto msbi_g+1) <= SigmaLatch_q(msbi_g+2) &
-                                        SigmaLatch_q(msbi_g+2);
-  DeltaB_s(msbi_g   downto        0) <= (others => '0');
-
-  DeltaAdder_s <= unsigned('0' & '0' & dac_i) + DeltaB_s;
-
-  SigmaAdder_s <= DeltaAdder_s + SigmaLatch_q;
-
-  seq: process (clk_i, res_n_i)
-  begin
-    if res_n_i = '0' then
-      SigmaLatch_q <= to_unsigned(2**(msbi_g+1), SigmaLatch_q'length);
-      DACout_q     <= '0';
-
-    elsif clk_i'event and clk_i = '1' then
-      SigmaLatch_q <= SigmaAdder_s;
-      DACout_q     <= SigmaLatch_q(msbi_g+2);
-    end if;
-  end process seq;
-
-  dac_o <= DACout_q;
-
-end rtl;