diff --git a/debug/hw-debug.adb b/debug/hw-debug.adb
new file mode 100644
index 0000000..3ffa9b5
--- /dev/null
+++ b/debug/hw-debug.adb
@@ -0,0 +1,284 @@
+--
+-- Copyright (C) 2015 secunet Security Networks AG
+--
+-- This program is free software; you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation; version 2 of the License.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+--
+
+with HW;
+with HW.Time;
+with HW.Debug_Sink;
+
+use type HW.Word64;
+use type HW.Int64;
+
+package body HW.Debug
+with
+   SPARK_Mode => Off
+is
+
+   Start_Of_Line : Boolean := True;
+   Register_Write_Delay_Nanoseconds : Word64 := 0;
+
+   type Base_Range is new Positive range 2 .. 16;
+   type Width_Range is new Natural range 0 .. 64;
+
+   procedure Put_By_Base
+     (Item        : Word64;
+      Min_Width   : Width_Range;
+      Base        : Base_Range);
+
+   procedure Do_Put_Int64
+     (Item        : Int64);
+
+   ----------------------------------------------------------------------------
+
+   procedure Put_Time
+   is
+      Now_US : Int64;
+   begin
+      if Start_Of_Line then
+         Start_Of_Line := False;
+         Now_US := Time.Now_US;
+         Debug_Sink.Put_Char ('[');
+         Do_Put_Int64 ((Now_US / 1_000_000) mod 1_000_000);
+         Debug_Sink.Put_Char ('.');
+         Put_By_Base (Word64 (Now_US mod 1_000_000), 6, 10);
+         Debug_Sink.Put ("] ");
+      end if;
+   end Put_Time;
+
+   ----------------------------------------------------------------------------
+
+   procedure Put (Item : String) is
+   begin
+      Put_Time;
+      HW.Debug_Sink.Put (Item);
+   end Put;
+
+   procedure Put_Line (Item : String) is
+   begin
+      Put (Item);
+      New_Line;
+   end Put_Line;
+
+   procedure New_Line is
+   begin
+      HW.Debug_Sink.New_Line;
+      Start_Of_Line := True;
+   end New_Line;
+
+   ----------------------------------------------------------------------------
+
+   procedure Put_By_Base
+     (Item        : Word64;
+      Min_Width   : Width_Range;
+      Base        : Base_Range)
+   is
+      Temp : Word64 := Item;
+
+      subtype Chars_Range is Width_Range range 0 .. 63;
+      Index : Width_Range := 0;
+
+      type Chars_Array is array (Chars_Range) of Character;
+      Chars : Chars_Array := (others => '0');
+
+      Digit : Natural;
+   begin
+      while Temp > 0 loop
+         Digit := Natural (Temp rem Word64 (Base));
+         if Digit < 10 then
+            Chars (Index) := Character'Val (Character'Pos ('0') + Digit);
+         else
+            Chars (Index) := Character'Val (Character'Pos ('a') + Digit - 10);
+         end if;
+         Temp := Temp / Word64 (Base);
+         Index := Index + 1;
+      end loop;
+      if Index < Min_Width then
+         Index := Min_Width;
+      end if;
+      for I in reverse Width_Range range 0 .. Index - 1 loop
+         HW.Debug_Sink.Put_Char (Chars (I));
+      end loop;
+   end Put_By_Base;
+
+   ----------------------------------------------------------------------------
+
+   procedure Put_Word
+     (Item        : Word64;
+      Min_Width   : Width_Range;
+      Print_Ox    : Boolean := True) is
+   begin
+      Put_Time;
+      if Print_Ox then
+         Put ("0x");
+      end if;
+      Put_By_Base (Item, Min_Width, 16);
+   end Put_Word;
+
+   procedure Put_Word8 (Item : Word8) is
+   begin
+      Put_Word (Word64 (Item), 2);
+   end Put_Word8;
+
+   procedure Put_Word16 (Item : Word16) is
+   begin
+      Put_Word (Word64 (Item), 4);
+   end Put_Word16;
+
+   procedure Put_Word32 (Item : Word32) is
+   begin
+      Put_Word (Word64 (Item), 8);
+   end Put_Word32;
+
+   procedure Put_Word64 (Item : Word64) is
+   begin
+      Put_Word (Item, 16);
+   end Put_Word64;
+
+   ----------------------------------------------------------------------------
+
+   procedure Do_Put_Int64 (Item : Int64)
+   is
+      Temp : Word64;
+   begin
+      if Item < 0 then
+         Debug_Sink.Put_Char ('-');
+         Temp := Word64 (-Item);
+      else
+         Temp := Word64 (Item);
+      end if;
+      Put_By_Base (Temp, 1, 10);
+   end Do_Put_Int64;
+
+   procedure Put_Int64 (Item : Int64)
+   is
+   begin
+      Put_Time;
+      Do_Put_Int64 (Item);
+   end Put_Int64;
+
+   procedure Put_Int8 (Item : Int8) is
+   begin
+      Put_Int64 (Int64 (Item));
+   end Put_Int8;
+
+   procedure Put_Int16 (Item : Int16) is
+   begin
+      Put_Int64 (Int64 (Item));
+   end Put_Int16;
+
+   procedure Put_Int32 (Item : Int32) is
+   begin
+      Put_Int64 (Int64 (Item));
+   end Put_Int32;
+
+   ----------------------------------------------------------------------------
+
+   procedure Put_Reg8 (Name : String; Item : Word8) is
+   begin
+      Put (Name);
+      Put (": ");
+      Put_Word8 (Item);
+      New_Line;
+   end Put_Reg8;
+
+   procedure Put_Reg16 (Name : String; Item : Word16)
+   is
+   begin
+      Put (Name);
+      Put (": ");
+      Put_Word16 (Item);
+      New_Line;
+   end Put_Reg16;
+
+   procedure Put_Reg32 (Name : String; Item : Word32)
+   is
+   begin
+      Put (Name);
+      Put (": ");
+      Put_Word32 (Item);
+      New_Line;
+   end Put_Reg32;
+
+   procedure Put_Reg64 (Name : String; Item : Word64)
+   is
+   begin
+      Put (Name);
+      Put (": ");
+      Put_Word64 (Item);
+      New_Line;
+   end Put_Reg64;
+
+   ----------------------------------------------------------------------------
+
+   procedure Put_Buffer
+     (Name  : String;
+      Buf   : Buffer;
+      Len   : Buffer_Range)
+   is
+      Line_Start, Left : Natural;
+   begin
+      if Len = 0 then
+         if Name'Length > 0 then
+            Put (Name);
+            Put_Line ("+0x00:");
+         end if;
+      else
+         Line_Start  := 0;
+         Left        := Len - 1;
+         for I in Natural range 1 .. ((Len + 15) / 16) loop
+            if Name'Length > 0 then
+               Put (Name);
+               Debug_Sink.Put_Char ('+');
+               Put_Word16 (Word16 (Line_Start));
+               Put (":  ");
+            end if;
+            for J in Natural range 0 .. Natural'Min (7, Left)
+            loop
+               Put_Word (Word64 (Buf (Line_Start + J)), 2, False);
+               Debug_Sink.Put_Char (' ');
+            end loop;
+
+            Debug_Sink.Put_Char (' ');
+            for J in Natural range 8 .. Natural'Min (15, Left)
+            loop
+               Put_Word (Word64(Buf (Line_Start + J)), 2, False);
+               Debug_Sink.Put_Char (' ');
+            end loop;
+            New_Line;
+
+            Line_Start  := Line_Start + 16;
+            Left        := Left - Natural'Min (Left, 16);
+         end loop;
+      end if;
+   end Put_Buffer;
+
+   ----------------------------------------------------------------------------
+
+   procedure Set_Register_Write_Delay (Value : Word64)
+   is
+   begin
+      Register_Write_Delay_Nanoseconds := Value;
+   end Set_Register_Write_Delay;
+
+   ----------------------------------------------------------------------------
+
+   Procedure Register_Write_Wait
+   is
+   begin
+      if Register_Write_Delay_Nanoseconds > 0 then
+         Time.U_Delay (Natural ((Register_Write_Delay_Nanoseconds + 999) / 1000));
+      end if;
+   end Register_Write_Wait;
+
+end HW.Debug;
+
+--  vim: set ts=8 sts=3 sw=3 et: