Thanks,
The application is an emergency light. When the mains fails the micro turns the light on via the battery. Every month, the micro must instigate a battery test (simply discharging and recharging thebattery), and every year it must do a longer batery test.
So i need to time a period of a year.
If i am using the PIC24FJ64GA004, then i obviously need a 32.768KHz crystal on the SOSCx pins.
However, that oscillator speed is too slow for the general functioning, so can i use the 8MHz internal oscillator aswell as the 32.768KHz external crystal?
...ie, just use the 32.768KHz crystal for the calendar, and use the 8MHz internal oscillator for the general program execution?