The following table shows the default jumper settings.
| Jumper | Default | Function |
|---|---|---|
| J2 | Closed | VDDBU current measurement |
| J17 | Open | Erases SAM3U firmware (not populated, reserved for factory configuration, should never be used by the end user). |
| J19 | Open | Enables JTAG-OB (closed=disables JTAG-OB) |
| J20 | Open | Enables JTAG-CDC (closed=disables JTAG-CDC) |