Check RTC LSE(External Xtal, 32.768kHz) mode
Please refer follow links.
My notebook
http://developer.mbed.org/users/kenjiArai/notebook/nucleo-series-clock-structure-and-xtal-oscillation/
Q&A for RTC Xtal
http://developer.mbed.org/questions/4531/RTC-External-Crystal-Nucleo/
History
STM team has changed start-up time but still has a problem. Simplified a checking procedure.
2015-05-16, by kenjiArai [Sat, 16 May 2015 23:38:13 +0000] rev 4
STM team has changed start-up time but still has a problem. Simplified a checking procedure.
Select two functions 1) Check start-up time, 2) Set RTC time and date
2014-11-01, by kenjiArai [Sat, 01 Nov 2014 01:48:56 +0000] rev 3
Select two functions 1) Check start-up time, 2) Set RTC time and date
Checking program for RTC module inside CPU. Only for Nucleo board such as L152RE, F401RE and F411.
2014-11-01, by kenjiArai [Sat, 01 Nov 2014 00:35:50 +0000] rev 2
Checking program for RTC module inside CPU. Only for Nucleo board such as L152RE, F401RE and F411.
RTC Clock test program only for Nucleo F401RE & F411RE. Standard Lib. cannot support a LSE(External 32.768kHz Xtal) mode due to short time-out setting (Other words, capacitor's value for Xtal are not optimize due to poor design consideration)
2014-10-25, by kenjiArai [Sat, 25 Oct 2014 05:42:45 +0000] rev 1
RTC Clock test program only for Nucleo F401RE & F411RE. Standard Lib. cannot support a LSE(External 32.768kHz Xtal) mode due to short time-out setting (Other words, capacitor's value for Xtal are not optimize due to poor design consideration)
Initial version.
2014-02-21, by bcostm [Fri, 21 Feb 2014 10:00:46 +0000] rev 0
Initial version.