hi folks!

Is there any method implementing a backup power system for PIC Micro? Just like the case of DS1302 RTC interfaced to PIC Micro (A real-time digital clock with calendar project). If you want to ensure that the clock/calendar info from DS1302 is up-to-date, then a simple 3v Lithium coin battery is adequate. Even for long-time power interruption.

Can we do the same approach with PIC Micro (only PIC Micro, the rest of the circuitry is off. A small battery, just enough to let PIC up and running for a long-period with or without power interruption?