195 lines
6.3 KiB
C
195 lines
6.3 KiB
C
/**
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* \file
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*
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* \brief System clock management
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*
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* Copyright (c) 2010-2015 Atmel Corporation. All rights reserved.
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*
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* \asf_license_start
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*
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* \page License
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* 3. The name of Atmel may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* 4. This software may only be redistributed and used in connection with an
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* Atmel microcontroller product.
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*
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* THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
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* EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
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* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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* \asf_license_stop
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*
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*/
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/*
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* Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
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*/
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#ifndef SYSCLK_H_INCLUDED
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#define SYSCLK_H_INCLUDED
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#include "parts.h"
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#include "conf_clock.h"
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#if SAM3S
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# include "sam3s/sysclk.h"
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#elif SAM3U
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# include "sam3u/sysclk.h"
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#elif SAM3N
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# include "sam3n/sysclk.h"
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#elif SAM3XA
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# include "sam3x/sysclk.h"
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#elif SAM4S
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# include "sam4s/sysclk.h"
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#elif SAM4E
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# include "sam4e/sysclk.h"
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#elif SAM4C
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# include "sam4c/sysclk.h"
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#elif SAM4CM
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# include "sam4cm/sysclk.h"
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#elif SAM4CP
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# include "sam4cp/sysclk.h"
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#elif SAM4L
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# include "sam4l/sysclk.h"
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#elif SAM4N
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# include "sam4n/sysclk.h"
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#elif SAMG
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# include "samg/sysclk.h"
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#elif SAMV71
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# include "samv71/sysclk.h"
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#elif SAMV70
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# include "samv70/sysclk.h"
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#elif SAME70
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# include "same70/sysclk.h"
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#elif SAMS70
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# include "sams70/sysclk.h"
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#elif (UC3A0 || UC3A1)
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# include "uc3a0_a1/sysclk.h"
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#elif UC3A3
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# include "uc3a3_a4/sysclk.h"
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#elif UC3B
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# include "uc3b0_b1/sysclk.h"
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#elif UC3C
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# include "uc3c/sysclk.h"
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#elif UC3D
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# include "uc3d/sysclk.h"
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#elif UC3L
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# include "uc3l/sysclk.h"
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#elif XMEGA
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# include "xmega/sysclk.h"
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#elif MEGA
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# include "mega/sysclk.h"
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#else
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# error Unsupported chip type
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#endif
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/**
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* \defgroup clk_group Clock Management
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*/
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/**
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* \ingroup clk_group
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* \defgroup sysclk_group System Clock Management
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*
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* See \ref sysclk_quickstart.
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*
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* The <em>sysclk</em> API covers the <em>system clock</em> and all
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* clocks derived from it. The system clock is a chip-internal clock on
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* which all <em>synchronous clocks</em>, i.e. CPU and bus/peripheral
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* clocks, are based. The system clock is typically generated from one
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* of a variety of sources, which may include crystal and RC oscillators
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* as well as PLLs. The clocks derived from the system clock are
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* sometimes also known as <em>synchronous clocks</em>, since they
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* always run synchronously with respect to each other, as opposed to
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* <em>generic clocks</em> which may run from different oscillators or
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* PLLs.
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*
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* Most applications should simply call sysclk_init() to initialize
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* everything related to the system clock and its source (oscillator,
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* PLL or DFLL), and leave it at that. More advanced applications, and
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* platform-specific drivers, may require additional services from the
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* clock system, some of which may be platform-specific.
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*
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* \section sysclk_group_platform Platform Dependencies
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*
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* The sysclk API is partially chip- or platform-specific. While all
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* platforms provide mostly the same functionality, there are some
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* variations around how different bus types and clock tree structures
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* are handled.
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*
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* The following functions are available on all platforms with the same
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* parameters and functionality. These functions may be called freely by
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* portable applications, drivers and services:
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* - sysclk_init()
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* - sysclk_set_source()
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* - sysclk_get_main_hz()
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* - sysclk_get_cpu_hz()
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* - sysclk_get_peripheral_bus_hz()
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*
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* The following functions are available on all platforms, but there may
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* be variations in the function signature (i.e. parameters) and
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* behavior. These functions are typically called by platform-specific
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* parts of drivers, and applications that aren't intended to be
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* portable:
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* - sysclk_enable_peripheral_clock()
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* - sysclk_disable_peripheral_clock()
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* - sysclk_enable_module()
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* - sysclk_disable_module()
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* - sysclk_module_is_enabled()
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* - sysclk_set_prescalers()
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*
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* All other functions should be considered platform-specific.
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* Enabling/disabling clocks to specific peripherals as well as
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* determining the speed of these clocks should be done by calling
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* functions provided by the driver for that peripheral.
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*
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* @{
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*/
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//! \name System Clock Initialization
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//@{
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/**
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* \fn void sysclk_init(void)
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* \brief Initialize the synchronous clock system.
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*
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* This function will initialize the system clock and its source. This
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* includes:
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* - Mask all synchronous clocks except for any clocks which are
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* essential for normal operation (for example internal memory
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* clocks).
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* - Set up the system clock prescalers as specified by the
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* application's configuration file.
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* - Enable the clock source specified by the application's
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* configuration file (oscillator or PLL) and wait for it to become
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* stable.
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* - Set the main system clock source to the clock specified by the
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* application's configuration file.
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*
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* Since all non-essential peripheral clocks are initially disabled, it
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* is the responsibility of the peripheral driver to re-enable any
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* clocks that are needed for normal operation.
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*/
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//@}
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//! @}
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#endif /* SYSCLK_H_INCLUDED */
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