This is a RTC additional function. This is only for Nucleo F401RE & F411RE mbed(Added L152RE, F334R8, L476RG & F746xx). If you connected battery backup circuit for internal RTC, you can make a power-off and reset condition. RTC still has proper time and date.

Dependents:   Nucleo_rtos_sample PB_Emma_Ethernet

Please refer following NOTE information.
/users/kenjiArai/notebook/nucleo-series-rtc-control-under-power-onoff-and-re/

Revision:
12:4074fe3e67c7
Parent:
9:1af4e107ca7b
Child:
13:44e5327acb05
diff -r fc7223031196 -r 4074fe3e67c7 modify_info_F334.h
--- a/modify_info_F334.h	Sat May 23 22:22:32 2015 +0000
+++ b/modify_info_F334.h	Fri Jan 29 07:35:34 2016 +0000
@@ -2,11 +2,11 @@
  * mbed Application program
  *      Library differ part (This is only information document)
  *
- * Copyright (c) 2015 Kenji Arai / JH1PJL
+ * Copyright (c) 2015,'16 Kenji Arai / JH1PJL
  *  http://www.page.sannet.ne.jp/kenjia/index.html
  *  http://mbed.org/users/kenjiArai/
- *      Created: May       23rd, 2015
- *      Revised: May       24th, 2015
+ *      Created: January   23rd, 2015
+ *      Revised: January   30th, 2016
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
  * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
@@ -19,8 +19,9 @@
 //      rtc_api.c -> rtc_api_F334.c
 //*************************************************************************************************
 //
-// (1) Update mbed-src library if you want
-// (2) File rtc_api_F334.c copy to directry /mbed-src/targets/hal/TARGET_STM/TARGET_NUCLEO_F334R8/
+// (1) Update mbed-dev library if you want
+// (2) File rtc_api_F334.c copy to directry
+//     /mbed-dev/targets/hal/TARGET_STM/TARGET_STM32F3/
 // (3) Delete rtc_api.c in the same directory
 // (4) Edit rtc_api_F334.c
 //      (a)Delete 1st line