diff --git a/common/hw-mmio_regs.ads b/common/hw-mmio_regs.ads
new file mode 100644
index 0000000..9aafed9
--- /dev/null
+++ b/common/hw-mmio_regs.ads
@@ -0,0 +1,127 @@
+--
+-- Copyright (C) 2016 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.Sub_Regs;
+with HW.MMIO_Range;
+
+use type HW.Word64;
+
+generic
+   with package Range_P is new MMIO_Range (<>);
+   Byte_Offset_O : Natural := 0;
+
+   with package Subs_P is new Sub_Regs (<>);
+   Regs : Subs_P.Array_T;
+
+package HW.MMIO_Regs
+is
+
+   Byte_Offset : Natural := Byte_Offset_O;
+
+   ----------------------------------------------------------------------------
+
+   procedure Read (Value : out Word8; Idx : Subs_P.Index_T)
+   with
+      Pre =>   ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) >= Integer (Range_P.Index_T'First) and
+               ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) <= Integer (Range_P.Index_T'Last) and
+               Range_P.Element_T'Size <= Word64'Size and
+               Regs (Idx).MSB < Range_P.Element_T'Size and
+               Regs (Idx).MSB >= Regs (Idx).LSB and
+               Regs (Idx).MSB - Regs (Idx).LSB + 1 <= Word8'Size;
+
+   procedure Read (Value : out Word16; Idx : Subs_P.Index_T)
+   with
+      Pre =>   ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) >= Integer (Range_P.Index_T'First) and
+               ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) <= Integer (Range_P.Index_T'Last) and
+               Range_P.Element_T'Size <= Word64'Size and
+               Regs (Idx).MSB < Range_P.Element_T'Size and
+               Regs (Idx).MSB >= Regs (Idx).LSB and
+               Regs (Idx).MSB - Regs (Idx).LSB + 1 <= Word16'Size;
+
+   procedure Read (Value : out Word32; Idx : Subs_P.Index_T)
+   with
+      Pre =>   ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) >= Integer (Range_P.Index_T'First) and
+               ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) <= Integer (Range_P.Index_T'Last) and
+               Range_P.Element_T'Size <= Word64'Size and
+               Regs (Idx).MSB < Range_P.Element_T'Size and
+               Regs (Idx).MSB >= Regs (Idx).LSB and
+               Regs (Idx).MSB - Regs (Idx).LSB + 1 <= Word32'Size;
+
+   procedure Read (Value : out Word64; Idx : Subs_P.Index_T)
+   with
+      Pre =>   ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) >= Integer (Range_P.Index_T'First) and
+               ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) <= Integer (Range_P.Index_T'Last) and
+               Range_P.Element_T'Size <= Word64'Size and
+               Regs (Idx).MSB < Range_P.Element_T'Size and
+               Regs (Idx).MSB >= Regs (Idx).LSB and
+               Regs (Idx).MSB - Regs (Idx).LSB + 1 <= Word64'Size;
+
+   ----------------------------------------------------------------------------
+
+   procedure Write (Idx : Subs_P.Index_T; Value : Word8)
+   with
+      Pre =>   ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) >= Integer (Range_P.Index_T'First) and
+               ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) <= Integer (Range_P.Index_T'Last) and
+               Range_P.Element_T'Size <= Word64'Size and
+               Regs (Idx).MSB < Range_P.Element_T'Size and
+               Regs (Idx).MSB >= Regs (Idx).LSB and
+               Regs (Idx).MSB - Regs (Idx).LSB + 1 <= Value'Size and
+               Word64 (Value) < Word64 (2 ** (Regs (Idx).MSB + 1 - Regs (Idx).LSB));
+
+   procedure Write (Idx : Subs_P.Index_T; Value : Word16)
+   with
+      Pre =>   ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) >= Integer (Range_P.Index_T'First) and
+               ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) <= Integer (Range_P.Index_T'Last) and
+               Range_P.Element_T'Size <= Word64'Size and
+               Regs (Idx).MSB < Range_P.Element_T'Size and
+               Regs (Idx).MSB >= Regs (Idx).LSB and
+               Regs (Idx).MSB - Regs (Idx).LSB + 1 <= Value'Size and
+               Word64 (Value) < Word64 (2 ** (Regs (Idx).MSB + 1 - Regs (Idx).LSB));
+
+   procedure Write (Idx : Subs_P.Index_T; Value : Word32)
+   with
+      Pre =>   ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) >= Integer (Range_P.Index_T'First) and
+               ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) <= Integer (Range_P.Index_T'Last) and
+               Range_P.Element_T'Size <= Word64'Size and
+               Regs (Idx).MSB < Range_P.Element_T'Size and
+               Regs (Idx).MSB >= Regs (Idx).LSB and
+               Regs (Idx).MSB - Regs (Idx).LSB + 1 <= Value'Size and
+               Word64 (Value) < Word64 (2 ** (Regs (Idx).MSB + 1 - Regs (Idx).LSB));
+
+   procedure Write (Idx : Subs_P.Index_T; Value : Word64)
+   with
+      Pre =>   ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) >= Integer (Range_P.Index_T'First) and
+               ((Byte_Offset + Regs (Idx).Byte_Offset) /
+                (Range_P.Element_T'Size / 8)) <= Integer (Range_P.Index_T'Last) and
+               Range_P.Element_T'Size <= Word64'Size and
+               Regs (Idx).MSB < Range_P.Element_T'Size and
+               Regs (Idx).MSB >= Regs (Idx).LSB and
+               Regs (Idx).MSB - Regs (Idx).LSB + 1 <= Value'Size and
+               Word64 (Value) < Word64 (2 ** (Regs (Idx).MSB + 1 - Regs (Idx).LSB));
+
+end HW.MMIO_Regs;