Hi, Frank,
i think you can use the code to set the MCG in FEE mode, but you have to connect the crystal to Extal/Xtal or Extal32/Xtal32 pins and know the clock frequency of crystal, so that you can figure out frdiv, drs parameters.
void BOARD_BootClockRUN(void)
{
CLOCK_SetSimSafeDivs();
CLOCK_InitOsc0(&g_defaultClockConfigRun.oscConfig);
CLOCK_SetXtal0Freq(BOARD_XTAL0_CLK_HZ);
/* CLOCK_BootToPeeMode(g_defaultClockConfigRun.mcgConfig.oscsel, kMCG_PllClkSelPll0,
&g_defaultClockConfigRun.mcgConfig.pll0Config);*/
CLOCK_BootToFeeMode(
mcg_oscsel_t oscsel, uint8_t frdiv, mcg_dmx32_t dmx32, mcg_drs_t drs, void (*fllStableDelay)(void))
CLOCK_SetInternalRefClkConfig(g_defaultClockConfigRun.mcgConfig.irclkEnableMode,
g_defaultClockConfigRun.mcgConfig.ircs, g_defaultClockConfigRun.mcgConfig.fcrdiv);
CLOCK_SetSimConfig(&g_defaultClockConfigRun.simConfig);
SystemCoreClock = g_defaultClockConfigRun.coreClock;
}
Hope it can help you
BR
xiangjun Rong