If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
2. 请参考数据手册（SPRS457E–MARCH 2009–REVISED JUNE 2011）第42页：
RTCXI G1 I PRTCS VDD12_PRTCSS Input PRTCSS: Crystal Input for PRTCSS oscillator S Note: If the RTC calendar is not used, this pin should be pulled down. For more pin termination details, see Section 6.7, Power Management and Real Time Clock Subsystem (PRTCSS).
RTCXO H1 O PRTCS VDD12_PRTCSS Output PRTCSS: Crystal Output for PRTCSS oscillator S Note: If the RTC calendar is not used, this pin should be left unconnected. For more pin termination details, see Section 6.7, Power Management and Real Time Clock Subsystem (PRTCSS).
