The SAMC21N Xplained Pro kit contains one mounted 32.768kHz crystal and a footprint for higher frequency crystals that can be used as clock sources for the SAMC21N. The crystals have cut-straps next to them that can be used to measure the oscillator safety factor. This is done by cutting the strap and adding a resistor across the strap. Information about oscillator allowance and safety factor can be found in appnote AVR4100. Information about clock calibration and compensation can be found in appnote AT03155.
| SAMC21N pin | Function | Shared functionality |
|---|---|---|
| PA00 | XIN32 | - |
| PA01 | XOUT32 | - |