How can I disable RTC and the hibernate-domain?

Hello,
I don't need in my application the RTC and hibernate-domain. The RTC_XTAL and th HIB-pins on my XMC4500-F144 are open. I'm not sure if this correct. How can I disable both?
I use the DAVE4-App CLOCK_XMC4 and have set fRTC and fSTDBY to internal slow oscillator. If I start the controller, he keep hanging in a while-loop of the startup routine (xmc4_scu.c):

/* API to select fRTC */
void XMC_SCU_HIB_SetRtcClockSource(const XMC_SCU_HIB_RTCCLKSRC_t source)
{
/* Wait until the update of HDCR register in hibernate domain is completed */
while((SCU_GENERAL->MIRRSTS) & SCU_GENERAL_MIRRSTS_HDCR_Msk)
{
}

SCU_HIBERNATE->HDCR = (SCU_HIBERNATE->HDCR & ((uint32_t)~SCU_HIBERNATE_HDCR_RCS_Msk)) |
((uint32_t)source);
}



Regards