kopia lustrzana https://github.com/solokeys/solo1
390 wiersze
12 KiB
C
390 wiersze
12 KiB
C
/***************************************************************************//**
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* @file system_efm32pg1b.c
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* @brief CMSIS Cortex-M3/M4 System Layer for EFM32 devices.
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* @version 5.2.2
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******************************************************************************
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* # License
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* <b>Copyright 2017 Silicon Laboratories, Inc. http://www.silabs.com</b>
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******************************************************************************
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*
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* Permission is granted to anyone to use this software for any purpose,
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* including commercial applications, and to alter it and redistribute it
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* freely, subject to the following restrictions:
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*
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* 1. The origin of this software must not be misrepresented; you must not
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* claim that you wrote the original software.@n
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* 2. Altered source versions must be plainly marked as such, and must not be
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* misrepresented as being the original software.@n
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* 3. This notice may not be removed or altered from any source distribution.
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*
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* DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Laboratories, Inc.
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* has no obligation to support this Software. Silicon Laboratories, Inc. is
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* providing the Software "AS IS", with no express or implied warranties of any
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* kind, including, but not limited to, any implied warranties of
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* merchantability or fitness for any particular purpose or warranties against
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* infringement of any proprietary rights of a third party.
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*
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* Silicon Laboratories, Inc. will not be liable for any consequential,
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* incidental, or special damages, or any other relief, or for any claim by
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* any third party, arising from your use of this Software.
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*
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*****************************************************************************/
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#include <stdint.h>
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#include "em_device.h"
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/*******************************************************************************
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****************************** DEFINES ************************************
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******************************************************************************/
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/** LFRCO frequency, tuned to below frequency during manufacturing. */
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#define EFM32_LFRCO_FREQ (32768UL)
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/** ULFRCO frequency */
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#define EFM32_ULFRCO_FREQ (1000UL)
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/*******************************************************************************
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************************** LOCAL VARIABLES ********************************
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******************************************************************************/
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/* System oscillator frequencies. These frequencies are normally constant */
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/* for a target, but they are made configurable in order to allow run-time */
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/* handling of different boards. The crystal oscillator clocks can be set */
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/* compile time to a non-default value by defining respective EFM_nFXO_FREQ */
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/* values according to board design. By defining the EFM_nFXO_FREQ to 0, */
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/* one indicates that the oscillator is not present, in order to save some */
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/* SW footprint. */
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#ifndef EFM32_HFRCO_MAX_FREQ
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/** Maximum HFRCO frequency */
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#define EFM32_HFRCO_MAX_FREQ (38000000UL)
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#endif
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#ifndef EFM32_HFXO_FREQ
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/** HFXO frequency */
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#define EFM32_HFXO_FREQ (40000000UL)
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#endif
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#ifndef EFM32_HFRCO_STARTUP_FREQ
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/** HFRCO startup frequency */
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#define EFM32_HFRCO_STARTUP_FREQ (19000000UL)
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#endif
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/* Do not define variable if HF crystal oscillator not present */
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#if (EFM32_HFXO_FREQ > 0UL)
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/** @cond DO_NOT_INCLUDE_WITH_DOXYGEN */
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/** System HFXO clock. */
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static uint32_t SystemHFXOClock = EFM32_HFXO_FREQ;
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/** @endcond (DO_NOT_INCLUDE_WITH_DOXYGEN) */
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#endif
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#ifndef EFM32_LFXO_FREQ
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/** LFXO frequency */
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#define EFM32_LFXO_FREQ (EFM32_LFRCO_FREQ)
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#endif
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/* Do not define variable if LF crystal oscillator not present */
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#if (EFM32_LFXO_FREQ > 0UL)
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/** @cond DO_NOT_INCLUDE_WITH_DOXYGEN */
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/** System LFXO clock. */
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static uint32_t SystemLFXOClock = 32768UL;
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/** @endcond (DO_NOT_INCLUDE_WITH_DOXYGEN) */
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#endif
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/*******************************************************************************
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************************** GLOBAL VARIABLES *******************************
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******************************************************************************/
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/**
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* @brief
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* System System Clock Frequency (Core Clock).
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*
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* @details
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* Required CMSIS global variable that must be kept up-to-date.
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*/
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uint32_t SystemCoreClock = EFM32_HFRCO_STARTUP_FREQ;
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/**
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* @brief
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* System HFRCO frequency
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*
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* @note
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* This is an EFM32 proprietary variable, not part of the CMSIS definition.
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*
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* @details
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* Frequency of the system HFRCO oscillator
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*/
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uint32_t SystemHfrcoFreq = EFM32_HFRCO_STARTUP_FREQ;
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/*******************************************************************************
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************************** GLOBAL FUNCTIONS *******************************
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******************************************************************************/
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/***************************************************************************//**
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* @brief
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* Get the current core clock frequency.
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*
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* @details
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* Calculate and get the current core clock frequency based on the current
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* configuration. Assuming that the SystemCoreClock global variable is
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* maintained, the core clock frequency is stored in that variable as well.
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* This function will however calculate the core clock based on actual HW
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* configuration. It will also update the SystemCoreClock global variable.
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*
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* @note
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* This is an EFM32 proprietary function, not part of the CMSIS definition.
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*
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* @return
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* The current core clock frequency in Hz.
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******************************************************************************/
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uint32_t SystemCoreClockGet(void)
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{
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uint32_t ret;
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uint32_t presc;
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ret = SystemHFClockGet();
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presc = (CMU->HFCOREPRESC & _CMU_HFCOREPRESC_PRESC_MASK) >>
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_CMU_HFCOREPRESC_PRESC_SHIFT;
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ret /= (presc + 1);
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/* Keep CMSIS system clock variable up-to-date */
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SystemCoreClock = ret;
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return ret;
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}
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/***************************************************************************//**
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* @brief
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* Get the maximum core clock frequency.
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*
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* @note
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* This is an EFM32 proprietary function, not part of the CMSIS definition.
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*
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* @return
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* The maximum core clock frequency in Hz.
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******************************************************************************/
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uint32_t SystemMaxCoreClockGet(void)
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{
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return (EFM32_HFRCO_MAX_FREQ > EFM32_HFXO_FREQ ? \
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EFM32_HFRCO_MAX_FREQ : EFM32_HFXO_FREQ);
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}
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/***************************************************************************//**
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* @brief
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* Get the current HFCLK frequency.
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*
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* @note
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* This is an EFM32 proprietary function, not part of the CMSIS definition.
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*
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* @return
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* The current HFCLK frequency in Hz.
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******************************************************************************/
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uint32_t SystemHFClockGet(void)
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{
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uint32_t ret;
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switch (CMU->HFCLKSTATUS & _CMU_HFCLKSTATUS_SELECTED_MASK)
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{
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case CMU_HFCLKSTATUS_SELECTED_LFXO:
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#if (EFM32_LFXO_FREQ > 0)
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ret = SystemLFXOClock;
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#else
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/* We should not get here, since core should not be clocked. May */
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/* be caused by a misconfiguration though. */
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ret = 0;
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#endif
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break;
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case CMU_HFCLKSTATUS_SELECTED_LFRCO:
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ret = EFM32_LFRCO_FREQ;
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break;
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case CMU_HFCLKSTATUS_SELECTED_HFXO:
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#if (EFM32_HFXO_FREQ > 0)
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ret = SystemHFXOClock;
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#else
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/* We should not get here, since core should not be clocked. May */
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/* be caused by a misconfiguration though. */
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ret = 0;
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#endif
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break;
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default: /* CMU_HFCLKSTATUS_SELECTED_HFRCO */
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ret = SystemHfrcoFreq;
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break;
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}
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return ret / (1U + ((CMU->HFPRESC & _CMU_HFPRESC_PRESC_MASK)
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>> _CMU_HFPRESC_PRESC_SHIFT));
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}
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/**************************************************************************//**
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* @brief
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* Get high frequency crystal oscillator clock frequency for target system.
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*
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* @note
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* This is an EFM32 proprietary function, not part of the CMSIS definition.
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*
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* @return
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* HFXO frequency in Hz.
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*****************************************************************************/
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uint32_t SystemHFXOClockGet(void)
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{
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/* External crystal oscillator present? */
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#if (EFM32_HFXO_FREQ > 0)
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return SystemHFXOClock;
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#else
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return 0;
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#endif
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}
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/**************************************************************************//**
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* @brief
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* Set high frequency crystal oscillator clock frequency for target system.
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*
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* @note
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* This function is mainly provided for being able to handle target systems
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* with different HF crystal oscillator frequencies run-time. If used, it
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* should probably only be used once during system startup.
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*
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* @note
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* This is an EFM32 proprietary function, not part of the CMSIS definition.
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*
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* @param[in] freq
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* HFXO frequency in Hz used for target.
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*****************************************************************************/
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void SystemHFXOClockSet(uint32_t freq)
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{
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/* External crystal oscillator present? */
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#if (EFM32_HFXO_FREQ > 0)
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SystemHFXOClock = freq;
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/* Update core clock frequency if HFXO is used to clock core */
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if ((CMU->HFCLKSTATUS & _CMU_HFCLKSTATUS_SELECTED_MASK) == CMU_HFCLKSTATUS_SELECTED_HFXO)
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{
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/* The function will update the global variable */
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SystemCoreClockGet();
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}
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#else
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(void)freq; /* Unused parameter */
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#endif
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}
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/**************************************************************************//**
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* @brief
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* Initialize the system.
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*
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* @details
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* Do required generic HW system init.
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*
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* @note
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* This function is invoked during system init, before the main() routine
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* and any data has been initialized. For this reason, it cannot do any
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* initialization of variables etc.
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*****************************************************************************/
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void SystemInit(void)
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{
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#if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
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/* Set floating point coprosessor access mode. */
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SCB->CPACR |= ((3UL << 10*2) | /* set CP10 Full Access */
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(3UL << 11*2) ); /* set CP11 Full Access */
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#endif
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}
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/**************************************************************************//**
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* @brief
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* Get low frequency RC oscillator clock frequency for target system.
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*
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* @note
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* This is an EFM32 proprietary function, not part of the CMSIS definition.
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*
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* @return
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* LFRCO frequency in Hz.
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*****************************************************************************/
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uint32_t SystemLFRCOClockGet(void)
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{
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/* Currently we assume that this frequency is properly tuned during */
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/* manufacturing and is not changed after reset. If future requirements */
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/* for re-tuning by user, we can add support for that. */
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return EFM32_LFRCO_FREQ;
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}
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/**************************************************************************//**
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* @brief
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* Get ultra low frequency RC oscillator clock frequency for target system.
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*
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* @note
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* This is an EFM32 proprietary function, not part of the CMSIS definition.
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*
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* @return
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* ULFRCO frequency in Hz.
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*****************************************************************************/
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uint32_t SystemULFRCOClockGet(void)
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{
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/* The ULFRCO frequency is not tuned, and can be very inaccurate */
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return EFM32_ULFRCO_FREQ;
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}
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/**************************************************************************//**
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* @brief
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* Get low frequency crystal oscillator clock frequency for target system.
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*
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* @note
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* This is an EFM32 proprietary function, not part of the CMSIS definition.
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*
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* @return
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* LFXO frequency in Hz.
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*****************************************************************************/
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uint32_t SystemLFXOClockGet(void)
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{
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/* External crystal oscillator present? */
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#if (EFM32_LFXO_FREQ > 0)
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return SystemLFXOClock;
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#else
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return 0;
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#endif
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}
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/**************************************************************************//**
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* @brief
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* Set low frequency crystal oscillator clock frequency for target system.
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*
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* @note
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* This function is mainly provided for being able to handle target systems
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* with different HF crystal oscillator frequencies run-time. If used, it
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* should probably only be used once during system startup.
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*
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* @note
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* This is an EFM32 proprietary function, not part of the CMSIS definition.
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*
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* @param[in] freq
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* LFXO frequency in Hz used for target.
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*****************************************************************************/
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void SystemLFXOClockSet(uint32_t freq)
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{
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/* External crystal oscillator present? */
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#if (EFM32_LFXO_FREQ > 0)
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SystemLFXOClock = freq;
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/* Update core clock frequency if LFXO is used to clock core */
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if ((CMU->HFCLKSTATUS & _CMU_HFCLKSTATUS_SELECTED_MASK) == CMU_HFCLKSTATUS_SELECTED_LFXO)
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{
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/* The function will update the global variable */
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SystemCoreClockGet();
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}
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#else
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(void)freq; /* Unused parameter */
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#endif
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}
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