text: /**
   * \file
   *
   * \brief System clock management
   *
   * Copyright (c) 2010-2015 Atmel Corporation. All rights reserved.
   *
   * \asf_license_start
   *
   * \page License
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice,
   *    this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * 3. The name of Atmel may not be used to endorse or promote products derived
   *    from this software without specific prior written permission.
   *
   * 4. This software may only be redistributed and used in connection with an
   *    Atmel microcontroller product.
   *
   * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
   * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   * \asf_license_stop
   *
   */
  /*
   * Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
   */
  #ifndef SYSCLK_H_INCLUDED
  #define SYSCLK_H_INCLUDED
  
  #include "parts.h"
  #include "conf_clock.h"
  
  #if SAM3S
  # include "sam3s/sysclk.h"
  #elif SAM3U
  # include "sam3u/sysclk.h"
  #elif SAM3N
  # include "sam3n/sysclk.h"
  #elif SAM3XA
  # include "sam3x/sysclk.h"
  #elif SAM4S
  # include "sam4s/sysclk.h"
  #elif SAM4E
  # include "sam4e/sysclk.h"
  #elif SAM4C
  # include "sam4c/sysclk.h"
  #elif SAM4CM
  # include "sam4cm/sysclk.h"
  #elif SAM4CP
  # include "sam4cp/sysclk.h"
  #elif SAM4L
  # include "sam4l/sysclk.h"
  #elif SAM4N
  # include "sam4n/sysclk.h"
  #elif SAMG
  # include "samg/sysclk.h"
  #elif (UC3A0 || UC3A1)
  # include "uc3a0_a1/sysclk.h"
  #elif UC3A3
  # include "uc3a3_a4/sysclk.h"
  #elif UC3B
  # include "uc3b0_b1/sysclk.h"
  #elif UC3C
  # include "uc3c/sysclk.h"
  #elif UC3D
  # include "uc3d/sysclk.h"
  #elif UC3L
  # include "uc3l/sysclk.h"
  #elif XMEGA
  # include "xmega/sysclk.h"
  #elif MEGA
  # include "mega/sysclk.h"
  #else
  # error Unsupported chip type
  #endif
  
  /**
   * \defgroup clk_group Clock Management
   */
  
  /**
   * \ingroup clk_group
   * \defgroup sysclk_group System Clock Management
   *
   * See \ref sysclk_quickstart.
   *
   * The <em>sysclk</em> API covers the <em>system clock</em> and all
   * clocks derived from it. The system clock is a chip-internal clock on
   * which all <em>synchronous clocks</em>, i.e. CPU and bus/peripheral
   * clocks, are based. The system clock is typically generated from one
   * of a variety of sources, which may include crystal and RC oscillators
   * as well as PLLs.  The clocks derived from the system clock are
   * sometimes also known as <em>synchronous clocks</em>, since they
   * always run synchronously with respect to each other, as opposed to
   * <em>generic clocks</em> which may run from different oscillators or
   * PLLs.
   *
   * Most applications should simply call sysclk_init() to initialize
   * everything related to the system clock and its source (oscillator,
   * PLL or DFLL), and leave it at that. More advanced applications, and
   * platform-specific drivers, may require additional services from the
   * clock system, some of which may be platform-specific.
   *
   * \section sysclk_group_platform Platform Dependencies
   *
   * The sysclk API is partially chip- or platform-specific. While all
   * platforms provide mostly the same functionality, there are some
   * variations around how different bus types and clock tree structures
   * are handled.
   *
   * The following functions are available on all platforms with the same
   * parameters and functionality. These functions may be called freely by
   * portable applications, drivers and services:
   *   - sysclk_init()
   *   - sysclk_set_source()
   *   - sysclk_get_main_hz()
   *   - sysclk_get_cpu_hz()
   *   - sysclk_get_peripheral_bus_hz()
   *
   * The following functions are available on all platforms, but there may
   * be variations in the function signature (i.e. parameters) and
   * behavior. These functions are typically called by platform-specific
   * parts of drivers, and applications that aren't intended to be
   * portable:
   *   - sysclk_enable_peripheral_clock()
   *   - sysclk_disable_peripheral_clock()
   *   - sysclk_enable_module()
   *   - sysclk_disable_module()
   *   - sysclk_module_is_enabled()
   *   - sysclk_set_prescalers()
   *
   * All other functions should be considered platform-specific.
   * Enabling/disabling clocks to specific peripherals as well as
   * determining the speed of these clocks should be done by calling
   * functions provided by the driver for that peripheral.
   *
   * @{
   */
  
  //! \name System Clock Initialization
  //@{
  /**
   * \fn void sysclk_init(void)
   * \brief Initialize the synchronous clock system.
   *
   * This function will initialize the system clock and its source. This
   * includes:
   *   - Mask all synchronous clocks except for any clocks which are
   *     essential for normal operation (for example internal memory
   *     clocks).
   *   - Set up the system clock prescalers as specified by the
   *     application's configuration file.
   *   - Enable the clock source specified by the application's
   *     configuration file (oscillator or PLL) and wait for it to become
   *     stable.
   *   - Set the main system clock source to the clock specified by the
   *     application's configuration file.
   *
   * Since all non-essential peripheral clocks are initially disabled, it
   * is the responsibility of the peripheral driver to re-enable any
   * clocks that are needed for normal operation.
   */
  //@}
  
  //! @}
  
  #endif /* SYSCLK_H_INCLUDED */
  