diff --git a/include/libopencm3/cm3/cortex.h b/include/libopencm3/cm3/cortex.h
index d334fc04..2818724d 100644
--- a/include/libopencm3/cm3/cortex.h
+++ b/include/libopencm3/cm3/cortex.h
@@ -1,7 +1,18 @@
+/** @defgroup CM3_cortex_defines Cortex Core Defines
+ *
+ * @brief <b>libopencm3 Defined Constants and Types for the Cortex Core </b>
+ *
+ * @ingroup CM3_defines
+ *
+ * @version 1.0.0
+ *
+ * LGPL License Terms @ref lgpl_license
+ */
 /*
  * This file is part of the libopencm3 project.
  *
- * Copyright (C) 2013 Ben Gamari <bgamari@gmail.com>
+ * Copyright (C) 2013 Ben Gamari <bgamari@gmail.com>
+ * 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
@@ -18,29 +29,58 @@
  */
 
 #ifndef LIBOPENCM3_CORTEX_H
-#define LIBOPENCM3_CORTEX_H
+#define LIBOPENCM3_CORTEX_H
+
+/**@{*/
 
+/*---------------------------------------------------------------------------*/
+/** @brief Cortex M Enable interrupts
+ *
+ * Disable the interrupt mask and enable interrupts globally
+ */
 static inline void cm_enable_interrupts(void)
 {
 	__asm__("CPSIE I\n");
 }
-
+
+/*---------------------------------------------------------------------------*/
+/** @brief Cortex M Disable interrupts
+ *
+ * Mask all interrupts globally
+ */
 static inline void cm_disable_interrupts(void)
 {
 	__asm__("CPSID I\n");
 }
 
+/*---------------------------------------------------------------------------*/
+/** @brief Cortex M Enable faults
+ *
+ * Disable the HardFault mask and enable fault interrupt globally
+ */
 static inline void cm_enable_faults(void)
 {
 	__asm__("CPSIE F\n");
 }
 
+/*---------------------------------------------------------------------------*/
+/** @brief Cortex M Disable faults
+ *
+ * Mask the HardFault interrupt globally
+ */
 static inline void cm_disable_faults(void)
 {
 	__asm__("CPSID F\n");
 }
-
-/* __attribute__(( always_inline )) */
+
+/*---------------------------------------------------------------------------*/
+/** @brief Cortex M Check if interrupts are masked
+ *
+ * Checks, if interrupts are masked (disabled).
+ *
+ * @returns true, if interrupts are disabled.
+ */
+__attribute__(( always_inline ))
 static inline bool cm_is_masked_interrupts(void)
 {
 	register uint32_t result;
@@ -48,15 +88,32 @@ static inline bool cm_is_masked_interrupts(void)
 	return (result);
 }
 
-/* __attribute__(( always_inline )) */
+/*---------------------------------------------------------------------------*/
+/** @brief Cortex M Check if Fault interrupt is masked
+ *
+ * Checks, if HardFault interrupt is masked (disabled).
+ *
+ * @returns bool true, if HardFault interrupt is disabled.
+ */
+__attribute__(( always_inline ))
 static inline bool cm_is_masked_faults(void)
 {
 	register uint32_t result;
 	__asm__ ("MRS %0, FAULTMASK"  : "=r" (result) );
 	return (result);
 }
-
-/* __attribute__(( always_inline )) */
+
+/*---------------------------------------------------------------------------*/
+/** @brief Cortex M Mask interrupts
+ *
+ * This function switches the mask of the interrupts. If mask is true, the
+ * interrupts will be disabled. The result of this function can be used for
+ * restoring previous state of the mask.
+ *
+ * @param[in] mask bool New state of the interrupt mask
+ * @returns bool old state of the interrupt mask
+ */
+__attribute__(( always_inline ))
 static inline bool cm_mask_interrupts(bool mask)
 {
 	register bool old;
@@ -65,8 +122,18 @@ static inline bool cm_mask_interrupts(bool mask)
 	__asm__ __volatile__("MSR PRIMASK, %0" : : "r" (mask));
 	return old;
 }
-
-/* __attribute__(( always_inline )) */
+
+/*---------------------------------------------------------------------------*/
+/** @brief Cortex M Mask HardFault interrupt
+ *
+ * This function switches the mask of the HardFault interrupt. If mask is true,
+ * the HardFault interrupt will be disabled. The result of this function can be
+ * used for restoring previous state of the mask.
+ *
+ * @param[in] mask bool New state of the HardFault interrupt mask
+ * @returns bool old state of the HardFault interrupt mask
+ */
+__attribute__(( always_inline ))
 static inline bool cm_mask_faults(bool mask)
 {
 	register bool old;
@@ -75,6 +142,7 @@ static inline bool cm_mask_faults(bool mask)
 	__asm__ __volatile__ ("MSR FAULTMASK, %0" : : "r" (mask));
 	return old;
 }
-
+
+/**@}*/
 
 #endif