diff --git a/common/hw-gfx-gma-pch-sideband.ads b/common/hw-gfx-gma-pch-sideband.ads
new file mode 100644
index 0000000..2d29275
--- /dev/null
+++ b/common/hw-gfx-gma-pch-sideband.ads
@@ -0,0 +1,49 @@
+--
+-- 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.
+--
+
+private package HW.GFX.GMA.PCH.Sideband is
+
+   type Destination_Type is (SBI_ICLK, SBI_MPHY);
+
+   type Register_Type is
+     (SBI_SSCDIVINTPHASE6,
+      SBI_SSCCTL6,
+      SBI_SSCAUXDIV);
+
+   procedure Read
+     (Dest     : in     Destination_Type;
+      Register : in     Register_Type;
+      Value    :    out Word32);
+
+   procedure Write
+     (Dest     : in     Destination_Type;
+      Register : in     Register_Type;
+      Value    : in     Word32);
+
+   procedure Unset_Mask
+     (Dest     : in     Destination_Type;
+      Register : in     Register_Type;
+      Mask     : in     Word32);
+
+   procedure Set_Mask
+     (Dest     : in     Destination_Type;
+      Register : in     Register_Type;
+      Mask     : in     Word32);
+
+   procedure Unset_And_Set_Mask
+     (Dest        : in     Destination_Type;
+      Register    : in     Register_Type;
+      Mask_Unset  : in     Word32;
+      Mask_Set    : in     Word32);
+
+end HW.GFX.GMA.PCH.Sideband;