4.3.2 Crystal

The ATtiny817 Xplained Pro kit contains a 32.768 kHz crystal, which can be used as a clock source for the ATtiny817 device. The crystal has a cut-strap next to it, which can be used to measure the oscillator safety factor. This is done by cutting the strap and adding a resistor across the strap. More information about oscillator allowance and safety factor can be found in the AN2648 application note from Microchip.

There is a 9 pF, 32.768 kHz crystal in a 3.2 mm by 1.5 mm package mounted on ATtiny817 Xplained Pro.

Info: The crystal is not connected to the device by default, as the crystal pins on the device are shared with the UART module. If the crystal is needed by the application, the UART interface is lost. See Kit Modifications for instructions on how to modify the kit for crystal operation.
Table 4-5. External 32.768 kHz Crystal
ATtiny817 PinFunction
PB2XOUT32
PB3XIN32