Energy Micro IEC60355 Library Example Project 1.0 (internal use only!) GCC-Version
Example project demonstrating POST and BIST library functions
Defines | Functions | Variables

system_efm32.c File Reference

CMSIS Cortex-M3 Peripheral Access Layer for EFM32 devices. More...

#include <stdint.h>
#include "efm32.h"
Include dependency graph for system_efm32.c:

Go to the source code of this file.

Defines

#define EFM32_LFRCO_FREQ   (32768)
#define EFM32_HFXO_FREQ   (32000000)
#define EFM32_LFXO_FREQ   (EFM32_LFRCO_FREQ)

Functions

uint32_t SystemCoreClockGet (void)
 Get the current core clock frequency.
uint32_t SystemHFClockGet (void)
 Get the current HFCLK frequency.
uint32_t SystemHFXOClockGet (void)
 Get high frequency crystal oscillator clock frequency for target system.
void SystemHFXOClockSet (uint32_t freq)
 Set high frequency crystal oscillator clock frequency for target system.
void SystemInit (void)
 Initialize the system.
uint32_t SystemLFRCOClockGet (void)
 Get low frequency RC oscillator clock frequency for target system.
uint32_t SystemLFXOClockGet (void)
 Get low frequency crystal oscillator clock frequency for target system.
void SystemLFXOClockSet (uint32_t freq)
 Set low frequency crystal oscillator clock frequency for target system.

Variables

uint32_t SystemCoreClock
 System System Clock Frequency (Core Clock).

Detailed Description

CMSIS Cortex-M3 Peripheral Access Layer for EFM32 devices.

Author:
Energy Micro AS
Version:
1.3.0

License

(C) Copyright 2010 Energy Micro AS, http://www.energymicro.com

This source code is the property of Energy Micro AS. The source and compiled code may only be used on Energy Micro "EFM32" microcontrollers.

This copyright notice may not be removed from the source code nor changed.

DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Energy Micro AS has no obligation to support this Software. Energy Micro AS is providing the Software "AS IS", with no express or implied warranties of any kind, including, but not limited to, any implied warranties of merchantability or fitness for any particular purpose or warranties against infringement of any proprietary rights of a third party.

Energy Micro AS will not be liable for any consequential, incidental, or special damages, or any other relief, or for any claim by any third party, arising from your use of this Software.

Definition in file system_efm32.c.

Define Documentation

#define EFM32_HFXO_FREQ   (32000000)

Definition at line 52 of file system_efm32.c.

#define EFM32_LFRCO_FREQ   (32768)

LFRCO frequency, tuned to below frequency during manufacturing.

Definition at line 37 of file system_efm32.c.

Referenced by SystemHFClockGet(), and SystemLFRCOClockGet().

#define EFM32_LFXO_FREQ   (EFM32_LFRCO_FREQ)

(DO_NOT_INCLUDE_WITH_DOXYGEN)

Definition at line 63 of file system_efm32.c.

Function Documentation

uint32_t SystemCoreClockGet ( void  )

Get the current core clock frequency.

Calculate and get the current core clock frequency based on the current configuration. Assuming that the SystemCoreClock global variable is maintained, the core clock frequency is stored in that variable as well. This function will however calculate the core clock based on actual HW configuration. It will also update the SystemCoreClock global variable.

Note:
This is an EFM32 proprietary function, not part of the CMSIS definition.
Returns:
The current core clock frequency in Hz.

Definition at line 108 of file system_efm32.c.

References SystemCoreClock, and SystemHFClockGet().

Referenced by SystemCoreClockUpdate(), SystemHFXOClockSet(), and SystemLFXOClockSet().

{
  uint32_t ret;
  
  ret = SystemHFClockGet();
  ret >>= (CMU->HFCORECLKDIV & _CMU_HFCORECLKDIV_HFCORECLKDIV_MASK) >> 
          _CMU_HFCORECLKDIV_HFCORECLKDIV_SHIFT;

  /* Keep CMSIS variable up-to-date just in case */
  SystemCoreClock = ret;

  return ret;
}

Here is the call graph for this function:

Here is the caller graph for this function:

uint32_t SystemHFClockGet ( void  )

Get the current HFCLK frequency.

Note:
This is an EFM32 proprietary function, not part of the CMSIS definition.
Returns:
The current HFCLK frequency in Hz.

Definition at line 133 of file system_efm32.c.

References EFM32_LFRCO_FREQ.

Referenced by SystemCoreClockGet().

{
  uint32_t ret;
  
  switch (CMU->STATUS & (CMU_STATUS_HFRCOSEL | CMU_STATUS_HFXOSEL |
                         CMU_STATUS_LFRCOSEL | CMU_STATUS_LFXOSEL))
  {
    case CMU_STATUS_LFXOSEL:
#if (EFM32_LFXO_FREQ > 0)
      ret = SystemLFXOClock;
#else
      /* We should not get here, since core should not be clocked. May */
      /* be caused by a misconfiguration though. */
      ret = 0;
#endif
      break;
      
    case CMU_STATUS_LFRCOSEL:
      ret = EFM32_LFRCO_FREQ;
      break;
      
    case CMU_STATUS_HFXOSEL:
#if (EFM32_HFXO_FREQ > 0)
      ret = SystemHFXOClock;
#else
      /* We should not get here, since core should not be clocked. May */
      /* be caused by a misconfiguration though. */
      ret = 0;
#endif
      break;
      
    default: /* CMU_STATUS_HFRCOSEL */
      switch (CMU->HFRCOCTRL & _CMU_HFRCOCTRL_BAND_MASK)
      {
      case CMU_HFRCOCTRL_BAND_28MHZ:
        ret = 28000000;
        break;

      case CMU_HFRCOCTRL_BAND_21MHZ:
        ret = 21000000;
        break;

      case CMU_HFRCOCTRL_BAND_14MHZ:
        ret = 14000000;
        break;

      case CMU_HFRCOCTRL_BAND_11MHZ:
        ret = 11000000;
        break;

      case CMU_HFRCOCTRL_BAND_7MHZ:
        ret = 7000000;
        break;

      case CMU_HFRCOCTRL_BAND_1MHZ:
        ret = 1000000;
        break;

      default:
        ret = 0;
        break;
      }
      break;
  }

  return ret;
}

Here is the caller graph for this function:

uint32_t SystemHFXOClockGet ( void  )

Get high frequency crystal oscillator clock frequency for target system.

Note:
This is an EFM32 proprietary function, not part of the CMSIS definition.
Returns:
HFXO frequency in Hz.

Definition at line 212 of file system_efm32.c.

{
  /* External crystal oscillator present? */
#if (EFM32_HFXO_FREQ > 0)
  return SystemHFXOClock;
#else
  return 0;
#endif
}
void SystemHFXOClockSet ( uint32_t  freq)

Set high frequency crystal oscillator clock frequency for target system.

Note:
This function is mainly provided for being able to handle target systems with different HF crystal oscillator frequencies run-time. If used, it should probably only be used once during system startup.
This is an EFM32 proprietary function, not part of the CMSIS definition.
Parameters:
[in]freqHFXO frequency in Hz used for target.

Definition at line 238 of file system_efm32.c.

References SystemCoreClockGet().

{
  /* External crystal oscillator present? */
#if (EFM32_HFXO_FREQ > 0)
  SystemHFXOClock = freq;

  /* Update core clock frequency if HFXO is used to clock core */
  if (CMU->STATUS & CMU_STATUS_HFXOSEL)
  {
    /* The function will update the global variable */
    SystemCoreClockGet();
  }
#else
  (void)freq; /* Unused parameter */
#endif
}

Here is the call graph for this function:

void SystemInit ( void  )

Initialize the system.

Do required generic HW system init.

Note:
This function is invoked during system init, before the main() routine and any data has been initialized. For this reason, it cannot do any initialization of variables etc.

Definition at line 268 of file system_efm32.c.

Referenced by Reset_Handler().

{
}

Here is the caller graph for this function:

uint32_t SystemLFRCOClockGet ( void  )

Get low frequency RC oscillator clock frequency for target system.

Note:
This is an EFM32 proprietary function, not part of the CMSIS definition.
Returns:
LFRCO frequency in Hz.

Definition at line 283 of file system_efm32.c.

References EFM32_LFRCO_FREQ.

{
  /* Currently we assume that this frequency is properly tuned during */
  /* manufacturing and is not changed after reset. If future requirements */
  /* for re-tuning by user, we can add support for that. */
  return EFM32_LFRCO_FREQ;
}
uint32_t SystemLFXOClockGet ( void  )

Get low frequency crystal oscillator clock frequency for target system.

Note:
This is an EFM32 proprietary function, not part of the CMSIS definition.
Returns:
LFXO frequency in Hz.

Definition at line 302 of file system_efm32.c.

{
  /* External crystal oscillator present? */
#if (EFM32_LFXO_FREQ > 0)
  return SystemLFXOClock;
#else
  return 0;
#endif
}
void SystemLFXOClockSet ( uint32_t  freq)

Set low frequency crystal oscillator clock frequency for target system.

Note:
This function is mainly provided for being able to handle target systems with different HF crystal oscillator frequencies run-time. If used, it should probably only be used once during system startup.
This is an EFM32 proprietary function, not part of the CMSIS definition.
Parameters:
[in]freqLFXO frequency in Hz used for target.

Definition at line 328 of file system_efm32.c.

References SystemCoreClockGet().

{
  /* External crystal oscillator present? */
#if (EFM32_LFXO_FREQ > 0)
  SystemLFXOClock = freq;

  /* Update core clock frequency if LFXO is used to clock core */
  if (CMU->STATUS & CMU_STATUS_LFXOSEL)
  {
    /* The function will update the global variable */
    SystemCoreClockGet();
  }
#else
  (void)freq; /* Unused parameter */
#endif
}

Here is the call graph for this function:

Variable Documentation

uint32_t SystemCoreClock

System System Clock Frequency (Core Clock).

(DO_NOT_INCLUDE_WITH_DOXYGEN)

Required CMSIS global variable that must be kept up-to-date.

Definition at line 85 of file system_efm32.c.

Referenced by SystemCoreClockGet().