Function CMU_ClockSelectGet

bsp/efm32/Libraries/emlib/src/em_cmu.c:1165–1305

/ * @brief * Get currently selected reference clock used for a clock branch. * * @param[in] clock * Clock branch to fetch selected ref. clock for. One of: * @li #cmuClock_HF * @li #cmuClock_LFA * @li #cmuClock_LFB * @li #cmuClock_USBC * @li #cmuClock_DBG * * @return * Reference clock used for clocking selected branch, #cmuSelect_Error if * invalid @p clock provided.

 *   invalid @p clock provided.
 *****************************************************************************/
CMU_Select_TypeDef CMU_ClockSelectGet(CMU_Clock_TypeDef clock)
{
  CMU_Select_TypeDef ret = cmuSelect_Disabled;
  uint32_t           selReg;

  selReg = (clock >> CMU_SEL_REG_POS) & CMU_SEL_REG_MASK;

  switch (selReg)
  {
  case CMU_HFCLKSEL_REG:
    switch (CMU->STATUS & (CMU_STATUS_HFRCOSEL | CMU_STATUS_HFXOSEL |
                           CMU_STATUS_LFRCOSEL | CMU_STATUS_LFXOSEL))
    {
    case CMU_STATUS_LFXOSEL:
      ret = cmuSelect_LFXO;
      break;

    case CMU_STATUS_LFRCOSEL:
      ret = cmuSelect_LFRCO;
      break;

    case CMU_STATUS_HFXOSEL:
      ret = cmuSelect_HFXO;
      break;

    default:
      ret = cmuSelect_HFRCO;
      break;
    }
    break;

  case CMU_LFACLKSEL_REG:
    switch (CMU->LFCLKSEL & _CMU_LFCLKSEL_LFA_MASK)
    {
    case _CMU_LFCLKSEL_LFA_LFRCO:
      ret = cmuSelect_LFRCO;
      break;

    case _CMU_LFCLKSEL_LFA_LFXO:
      ret = cmuSelect_LFXO;
      break;

    case _CMU_LFCLKSEL_LFA_HFCORECLKLEDIV2:
      ret = cmuSelect_CORELEDIV2;
      break;

    default:
#if defined(_EFM32_TINY_FAMILY) || defined(_EFM32_GIANT_FAMILY)
      if (CMU->LFCLKSEL & _CMU_LFCLKSEL_LFAE_MASK)
      {
        ret = cmuSelect_ULFRCO;
        break;
      }
#else
      ret = cmuSelect_Disabled;
#endif
      break;
    }