Description: Standard 'Watch' or Real-Time-Clock crystal.
32.768kHz means it is precisely half of a 16-bit counter.
Start counting at 0x8000 (or 32768). When the counter rolls over from 65535 to 0, then you know that exactly one second has passed. Reset the interrupt, reset the counter, and start counting again.
Frequency: 32.768 kHz / 32768Hz
Case Size: 3mm x 8mm
Load capacitance: 6pf
Frequancy tolerance: ±20 ppm
Pin count: 2 pins