All,
Hardware and Software requiremens for RTC only mode has been posted to the TI Embedded Processors Wiki. We are working on updating datasheets of the C5505/04/15/14. In the mean time, please get the details from the link below.
http://processors.wiki.ti.com/index.php/RTC_Mode_on_the_C5505/04/15/14
Best Regards,
Peter Chung