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/**
* \file
*
* \brief Chip-specific system clock management functions.
*
* Copyright (c) 2011-2015 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="https://www.atmel.com/design-support/">Atmel Support</a>
*/
#ifndef CHIP_SYSCLK_H_INCLUDED
#define CHIP_SYSCLK_H_INCLUDED
#include "osc.h"
#include "pll.h"
/**
* \page sysclk_quickstart Quick Start Guide for the System Clock Management service (SAM3A)
*
* This is the quick start guide for the \ref sysclk_group "System Clock Management"
* service, with step-by-step instructions on how to configure and use the service for
* specific use cases.
*
* \section sysclk_quickstart_usecases System Clock Management use cases
* - \ref sysclk_quickstart_basic
*
* \section sysclk_quickstart_basic Basic usage of the System Clock Management service
* This section will present a basic use case for the System Clock Management service.
* This use case will configure the main system clock to 84MHz, using an internal PLL
* module to multiply the frequency of a crystal attached to the microcontroller.
*
* \subsection sysclk_quickstart_use_case_1_prereq Prerequisites
* - None
*
* \subsection sysclk_quickstart_use_case_1_setup_steps Initialization code
* Add to the application initialization code:
* \code
sysclk_init();
\endcode
*
* \subsection sysclk_quickstart_use_case_1_setup_steps_workflow Workflow
* -# Configure the system clocks according to the settings in conf_clock.h:
* \code sysclk_init(); \endcode
*
* \subsection sysclk_quickstart_use_case_1_example_code Example code
* Add or uncomment the following in your conf_clock.h header file, commenting out all other
* definitions of the same symbol(s):
* \code
#define CONFIG_SYSCLK_SOURCE SYSCLK_SRC_PLLACK
// Fpll0 = (Fclk * PLL_mul) / PLL_div
#define CONFIG_PLL0_SOURCE PLL_SRC_MAINCK_XTAL
#define CONFIG_PLL0_MUL (84000000UL / BOARD_FREQ_MAINCK_XTAL)
#define CONFIG_PLL0_DIV 1
// Fbus = Fsys / BUS_div
#define CONFIG_SYSCLK_PRES SYSCLK_PRES_1
\endcode
*
* \subsection sysclk_quickstart_use_case_1_example_workflow Workflow
* -# Configure the main system clock to use the output of the PLL module as its source:
* \code #define CONFIG_SYSCLK_SOURCE SYSCLK_SRC_PLLACK \endcode
* -# Configure the PLL module to use the fast external fast crystal oscillator as its source:
* \code #define CONFIG_PLL0_SOURCE PLL_SRC_MAINCK_XTAL \endcode
* -# Configure the PLL module to multiply the external fast crystal oscillator frequency up to 84MHz:
* \code
#define CONFIG_PLL0_MUL (84000000UL / BOARD_FREQ_MAINCK_XTAL)
#define CONFIG_PLL0_DIV 1
\endcode
* \note For user boards, \c BOARD_FREQ_MAINCK_XTAL should be defined in the board \c conf_board.h configuration
* file as the frequency of the fast crystal attached to the microcontroller.
* -# Configure the main clock to run at the full 84MHz, disable scaling of the main system clock speed:
* \code
#define CONFIG_SYSCLK_PRES SYSCLK_PRES_1
\endcode
* \note Some dividers are powers of two, while others are integer division factors. Refer to the
* formulas in the conf_clock.h template commented above each division define.
*/
/// @cond 0
/**INDENT-OFF**/
#ifdef __cplusplus
extern "C" {
#endif
/**INDENT-ON**/
/// @endcond
/**
* \weakgroup sysclk_group
* @{
*/
//! \name Configuration Symbols
//@{
/**
* \def CONFIG_SYSCLK_SOURCE
* \brief Initial/static main system clock source
*
* The main system clock will be configured to use this clock during
* initialization.
*/
#ifndef CONFIG_SYSCLK_SOURCE
# define CONFIG_SYSCLK_SOURCE SYSCLK_SRC_MAINCK_4M_RC
#endif
/**
* \def CONFIG_SYSCLK_PRES
* \brief Initial CPU clock divider (mck)
*
* The MCK will run at
* \f[
* f_{MCK} = \frac{f_{sys}}{\mathrm{CONFIG\_SYSCLK\_PRES}}\,\mbox{Hz}
* \f]
* after initialization.
*/
#ifndef CONFIG_SYSCLK_PRES
# define CONFIG_SYSCLK_PRES 0
#endif
//@}
//! \name Master Clock Sources (MCK)
//@{
#define SYSCLK_SRC_SLCK_RC 0 //!< Internal 32kHz RC oscillator as master source clock
#define SYSCLK_SRC_SLCK_XTAL 1 //!< External 32kHz crystal oscillator as master source clock
#define SYSCLK_SRC_SLCK_BYPASS 2 //!< External 32kHz bypass oscillator as master source clock
#define SYSCLK_SRC_MAINCK_4M_RC 3 //!< Internal 4MHz RC oscillator as master source clock
#define SYSCLK_SRC_MAINCK_8M_RC 4 //!< Internal 8MHz RC oscillator as master source clock
#define SYSCLK_SRC_MAINCK_12M_RC 5 //!< Internal 12MHz RC oscillator as master source clock
#define SYSCLK_SRC_MAINCK_XTAL 6 //!< External crystal oscillator as master source clock
#define SYSCLK_SRC_MAINCK_BYPASS 7 //!< External bypass oscillator as master source clock
#define SYSCLK_SRC_PLLACK 8 //!< Use PLLACK as master source clock
#define SYSCLK_SRC_UPLLCK 9 //!< Use UPLLCK as master source clock
//@}
//! \name Master Clock Prescalers (MCK)
//@{
#define SYSCLK_PRES_1 PMC_MCKR_PRES_CLK_1 //!< Set master clock prescaler to 1
#define SYSCLK_PRES_2 PMC_MCKR_PRES_CLK_2 //!< Set master clock prescaler to 2
#define SYSCLK_PRES_4 PMC_MCKR_PRES_CLK_4 //!< Set master clock prescaler to 4
#define SYSCLK_PRES_8 PMC_MCKR_PRES_CLK_8 //!< Set master clock prescaler to 8
#define SYSCLK_PRES_16 PMC_MCKR_PRES_CLK_16 //!< Set master clock prescaler to 16
#define SYSCLK_PRES_32 PMC_MCKR_PRES_CLK_32 //!< Set master clock prescaler to 32
#define SYSCLK_PRES_64 PMC_MCKR_PRES_CLK_64 //!< Set master clock prescaler to 64
#define SYSCLK_PRES_3 PMC_MCKR_PRES_CLK_3 //!< Set master clock prescaler to 3
//@}
//! \name USB Clock Sources
//@{
#define USBCLK_SRC_PLL0 0 //!< Use PLLA
#define USBCLK_SRC_UPLL 1 //!< Use UPLL
//@}
/**
* \def CONFIG_USBCLK_SOURCE
* \brief Configuration symbol for the USB generic clock source
*
* Sets the clock source to use for the USB. The source must also be properly
* configured.
*
* Define this to one of the \c USBCLK_SRC_xxx settings. Leave it undefined if
* USB is not required.
*/
#ifdef __DOXYGEN__
# define CONFIG_USBCLK_SOURCE
#endif
/**
* \def CONFIG_USBCLK_DIV
* \brief Configuration symbol for the USB generic clock divider setting
*
* Sets the clock division for the USB generic clock. If a USB clock source is
* selected with CONFIG_USBCLK_SOURCE, this configuration symbol must also be
* defined.
*/
#ifdef __DOXYGEN__
# define CONFIG_USBCLK_DIV
#endif
extern void sysclk_enable_usb(void);
extern void sysclk_disable_usb(void);
//! @}
/// @cond 0
/**INDENT-OFF**/
#ifdef __cplusplus
}
#endif
/**INDENT-ON**/
/// @endcond
#endif /* CHIP_SYSCLK_H_INCLUDED */
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