Crystal 32.7khrz? specficcations 48MHz ?

[ThomasLengeling]

The schematics say that the board is using a 32.7hrz and the specifications mention that the board runs at 48Mhrz. Does the board runs with the external clock or the internal?

Thank you for your help.

[spacenate]

An external 32.768 kHz crystal oscillator allows for higher accuracy (and is required for some peripherals, i.e USB in host mode).

See this excellent blog post for more details: https://blog.thea.codes/understanding-the-sam-d21-clocks/