diff --git a/include/libopencm3/ethernet/phy_ste100.h b/include/libopencm3/ethernet/phy_ste100.h
new file mode 100644
index 00000000..3e9ce9fd
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+++ b/include/libopencm3/ethernet/phy_ste100.h
@@ -0,0 +1,140 @@
+/** @defgroup ethernet_phy_ste100_defines PHY STE100 Defines
+ *
+ * @brief <b>Defined Constants and Types for the Ethernet PHY STE100 chip</b>
+ *
+ * @ingroup ETH
+ *
+ * @version 1.0.0
+ *
+ * @author @htmlonly &copy; @endhtmlonly 2014 Frantisek Burian <BuFran@seznam.cz>
+ *
+ * @date 6 February 2014
+ *
+ * LGPL License Terms @ref lgpl_license
+ */
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2013 Frantisek Burian <BuFran@seznam.cz>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LIBOPENCM3_PHY_STE100_H
+#define LIBOPENCM3_PHY_STE100_H
+
+#include <libopencm3/ethernet/phy.h>
+
+/**@{*/
+
+/*
+ * Architecture availability:
+ *
+ */
+
+/*****************************************************************************/
+/* Register definitions                                                      */
+/*****************************************************************************/
+
+#define STE100_XCR				0x00
+#define STE100_XSR				0x01
+#define STE100_PID1				0x02
+#define STE100_PID2				0x03
+#define STE100_ANA				0x04
+#define STE100_ANLPA				0x05
+#define STE100_ANE				0x06
+
+#define STE100_XCIIS				0x11
+#define STE100_XIE				0x12
+#define STE100_100CTR				0x13
+#define STE100_XMC				0x14
+
+
+/*****************************************************************************/
+/* Register values                                                           */
+/*****************************************************************************/
+
+/* STE100_XCR ---------------------------------------------------------------*/
+/* STE100_XSR ---------------------------------------------------------------*/
+/* STE100_PID1 --------------------------------------------------------------*/
+/* STE100_PID2 --------------------------------------------------------------*/
+/* STE100_ANA ---------------------------------------------------------------*/
+/* STE100_ANLPA -------------------------------------------------------------*/
+/* STE100_ANE ---------------------------------------------------------------*/
+
+/* STE100_XCIIS -------------------------------------------------------------*/
+
+#define STE100_XCIIS_SPEED			(1 << 9)
+#define STE100_XCIIS_DUPLEX			(1 << 8)
+#define STE100_XCIIS_PAUSE			(1 << 7)
+#define STE100_XCIIS_ANC			(1 << 6)
+#define STE100_XCIIS_RFD			(1 << 5)
+#define STE100_XCIIS_LS				(1 << 4)
+#define STE100_XCIIS_ANAR			(1 << 3)
+#define STE100_XCIIS_PDF			(1 << 2)
+#define STE100_XCIIS_ANPR			(1 << 1)
+#define STE100_XCIIS_REF			(1 << 0)
+
+/* STE100_XIE ---------------------------------------------------------------*/
+
+#define STE100_XCIE_ANCE			(1 << 6)
+#define STE100_XCIE_RFE				(1 << 5)
+#define STE100_XCIE_LDE				(1 << 4)
+#define STE100_XCIE_ANAE			(1 << 3)
+#define STE100_XCIE_PDFE			(1 << 2)
+#define STE100_XCIE_ANPE			(1 << 1)
+#define STE100_XCIE_REFE			(1 << 0)
+
+/* STE100_100CTR ------------------------------------------------------------*/
+
+#define STE100_100CTR_DISRER			(1 << 13)
+#define STE100_100CTR_ANC			(1 << 12)
+#define STE100_100CTR_ENRLB			(1 << 9)
+#define STE100_100CTR_ENDCR			(1 << 8)
+#define STE100_100CTR_ENRZI			(1 << 7)
+#define STE100_100CTR_EN4B5B			(1 << 6)
+#define STE100_100CTR_ISOTX			(1 << 5)
+
+#define STE100_100CTR_CMODE_SHIFT		2
+#define STE100_100CTR_CMODE			(7 << STE100_100CTR_CMODE_SHIFT)
+#define STE100_100CTR_CMODE_AN			(0 << STE100_100CTR_CMODE_SHIFT)
+#define STE100_100CTR_CMODE_10HD		(1 << STE100_100CTR_CMODE_SHIFT)
+#define STE100_100CTR_CMODE_100HD		(2 << STE100_100CTR_CMODE_SHIFT)
+#define STE100_100CTR_CMODE_10FD		(5 << STE100_100CTR_CMODE_SHIFT)
+#define STE100_100CTR_CMODE_100FD		(6 << STE100_100CTR_CMODE_SHIFT)
+#define STE100_100CTR_CMODE_ISOLATE		(7 << STE100_100CTR_CMODE_SHIFT)
+
+#define STE100_100CTR_DISMLT			(1 << 1)
+#define STE100_100CTR_DISCRM			(1 << 0)
+
+/* STE100_XMC ---------------------------------------------------------------*/
+
+#define STE100_XMC_LD				(1 << 11)
+#define STE100_XMC_PAD_SHIFT			3
+#define STE100_XMC_PAD				(31 << STE100_XMC_PAD_SHIFT)
+
+#define STE100_XMC_MFPSE			(1 << 1)
+
+/*****************************************************************************/
+/* API definitions                                                           */
+/*****************************************************************************/
+
+/*****************************************************************************/
+/* API Functions                                                             */
+/*****************************************************************************/
+
+/**@}*/
+
+
+#endif /* LIBOPENCM3_PHY_STE100_H__ */