A. The low-frequency (LF) crystal oscillator and the corresponding LFXIN and LFXOUT pins are available in the MSP430FR5x6x and MSP430FR5x4x devices only.
RTC_B is available only in conjunction with the LF crystal oscillator in MSP430FR5x6x and MSP430FR5x4x devices.
B. The high-frequency (HF) crystal oscillator and the corresponding HFXIN and HFXOUT pins are available in the MSP430FR5x6x and MSP430FR5x5x devices only.
Figure 1-1 Functional Block Diagram
MSP430FR5x5x devices with the HF crystal oscillator only do not include the RTC_B module.