need real time clock tutorial for s130 nr51822

[puff]

Is there a simple way to have linux time up and running with minimum current consumption and good accuracy?

Preferably, some class with get_unix_time and set_unix_time methods, with a resolution of up to seconds.

[brianreinhold]

I guess my question really comes down to this: Does the chip have a built in CMOS timer? If not, then it's pretty clear what needs to be done. Some source of power must be provided.

[ovrebekk]

Hi

The chip has built in clock sources both for the LF clock and the HF clock, but they both require a power supply, and they are not very accurate (5-10% deviation worst case). 

In other words there is no way for the chip to track time without a power supply, and there is no way for the chip to accurately track time without an external crystal. 

Best regards
Torbjørn