The SAM4N Xplained Pro kit contains two crystals that can be used
as clock sources for the SAM4N device. Each crystal has a cut-strap next to it that 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 applicaton note AVR4100. Calculations for the selected
crystal can be found in the schematics documentation of the
board.
Table 1. External 32.768kHz
Crystal
| Pin on SAM4N |
Function |
| PA7 |
XIN32 |
| PA8 |
XOUT32 |
Table 2. External 12MHz
Crystal
| Pin on SAM4N |
Function |
| PB9 |
XIN |
| PB8 |
XOUT |