Check RTC LSE(External Xtal, 32.768kHz) mode

Dependencies:   mbed CheckRTC

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/

mbed.bld

Committer:
bcostm
Date:
2014-02-21
Revision:
0:bad75bd13618
Child:
1:eaa3c3f36c03

File content as of revision 0:bad75bd13618:

http://mbed.org/users/mbed_official/code/mbed/builds/ed8466a608b4