The SAM E54 Xplained Pro board is operated at 3.3V by
default, but it also has the possibility of running at lower voltages from an external
supply. The EDBG is designed to run from a 3.3V supply and won't work on other voltages,
therefore all connections from the EDBG and the on board 3.3V regulator to the ATSAME54P20A have to be removed.
To completely disconnect the EDBG and the on-board power supply from the ATSAME54P20A do the following:
- Remove the two jumpers from the
on-board 3-pin current measurement headers (J100 and J102), and connect the two
center pins (pin 2) together with a wire or an ammeter, as shown in Figure 2
- Remove R802, R803, R808, R809, R810,
R811, R812, R813, R814, R815, R816, R817, R818, R824, R825, R826, R827
- Optionally cut J101 to remove power
to the on-board current measurement headers (J100 and J102) from the on-board
regulator
Figure 1 shows all components that have to be removed from the
bottom side of the PCB for operation at other voltages. To locate the other components,
see the assembly drawing in the section above. When the components are removed, the kit
can be supplied with a desired voltage through the pins marked 3.3V (pin four) and GND
(pin two) on the Xplained Pro power header. To program and debug the ATSAME54P20A the 2x5 50mil Cortex debug
connector has to be used with an external debugger.
Info: Operating
the ATSAME54P20A on other voltages than 3.3V
requires physical modifications on the kit using a soldering iron and an external
debugger for programming the ATSAME54P20A. The
on-board current measurement only works at 3.3V. The on-board LED is selected for 3.3V
operation, the light level at 1.8V operation is very low. To increase the emitted light
level the value of the series resistor can be lowered. The EDBG functionality can be
restored by re-soldering the removed components and soldering a 0Ω resistor over
J101.
CAUTION: The voltage supplied
through the power header is applied directly to the ATSAME54P20A and the extension headers. Applying a voltage greater than 3.3V
may damage the board permanently.
Figure 1. SAM E54 Xplained Pro EDBG
Disconnect
Figure 2. SAM E54 Xplained Pro Current
Measurement Headers