diff --git a/proof/hw-mmio_range.adb b/proof/hw-mmio_range.adb
new file mode 100644
index 0000000..d96fc4b
--- /dev/null
+++ b/proof/hw-mmio_range.adb
@@ -0,0 +1,44 @@
+--
+-- 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.
+--
+
+package body HW.MMIO_Range
+with
+   Refined_State =>
+     (State => Range_A,
+      Base_Address => Address)
+is
+
+   Range_A : Array_T
+   with
+      Volatile,
+      Async_Readers, Async_Writers, Effective_Reads, Effective_Writes,
+      Import;
+
+   Address : Word64 := Base_Addr;
+
+   procedure Read (Value : out Element_T; Index : in Index_T) is
+   begin
+      Value := Range_A (Index);
+   end Read;
+
+   procedure Write (Index : in Index_T; Value: in Element_T) is
+   begin
+      Range_A (Index) := Value;
+   end Write;
+
+   procedure Set_Base_Address (Base : Word64) is
+   begin
+      Address := Base;
+   end Set_Base_Address;
+
+end HW.MMIO_Range;