Function CMU_LFClkGet

bsp/efm32/Libraries/emlib/src/em_cmu.c:348–403

/ * @brief * Get the LFnCLK frequency based on current configuration. * * @param[in] lfClkBranch * LF branch, 0 = LFA, 1 = LFB, ... * * @return * The LFnCLK frequency in Hz. If no LFnCLK is selected (disabled), 0 is * returned. ******************************************************************************/

 *   returned.
 ******************************************************************************/
static uint32_t CMU_LFClkGet(unsigned int lfClkBranch)
{
  uint32_t ret;

  EFM_ASSERT(lfClkBranch == CMU_LFA || lfClkBranch == CMU_LFB);

  switch ((CMU->LFCLKSEL >> (lfClkBranch * 2)) & 0x3)
  {
  case _CMU_LFCLKSEL_LFA_LFRCO:
    ret = SystemLFRCOClockGet();
    break;

  case _CMU_LFCLKSEL_LFA_LFXO:
    ret = SystemLFXOClockGet();
    break;

  case _CMU_LFCLKSEL_LFA_HFCORECLKLEDIV2:
#if defined (_EFM32_GIANT_FAMILY)
    /* Giant Gecko can use a /4 divider (and must if >32MHz) or HFLE is set */
    if(((CMU->HFCORECLKDIV & _CMU_HFCORECLKDIV_HFCORECLKLEDIV_MASK) == CMU_HFCORECLKDIV_HFCORECLKLEDIV_DIV4)||
       (CMU->CTRL & CMU_CTRL_HFLE))
    {
      ret = SystemCoreClockGet() / 4;
    }
    else
    {
      ret = SystemCoreClockGet() / 2;
    }
#else
    ret = SystemCoreClockGet() / 2;
#endif
    break;

  case _CMU_LFCLKSEL_LFA_DISABLED:
#if defined (_EFM32_GIANT_FAMILY) || defined (_EFM32_TINY_FAMILY)
    /* Check LF Extended bit setting for ULFRCO clock */
    if(CMU->LFCLKSEL >> (_CMU_LFCLKSEL_LFAE_SHIFT + lfClkBranch * 4))
    {
      ret = SystemULFRCOClockGet();
    }
    else
    {
      ret = 0;
    }
#else
    ret = 0;
#endif
    break;

  default:
    ret = 0;
    break;
  }

  return ret;
}