On the SAM L21 Xplained Pro the MCU and the MCU peripherals (e.g. extensions)
are powered by its own regulator as shown in Figure 1. All other parts of the board, mainly
embedded debugger and accompanying Xplained Pro Analog Module (XAM), are
powered from a separate regulator. The current to the MCU and peripherals
can be measured by connecting them to the XAM output through jumper
settings.
Figure 1. SAM L21 Xplained
Pro XAM Implementation Block
Diagram
On the
SAM L21 Xplained
Pro the XAM can be used in
four configurations:
- 1.No current
measurement or external MCU current measurement:
The XAM is bypassed and thus the MCU and peripherals are
supplied directly by the regulator. Set both jumpers in the
"BYPASS" position. In this configuration it is also possible
to connect external measurement tools on the Xplained Pro
MCU power measurement header to measure MCU current directly
instead of using the XAM.
- 2.MCU current
measurement: The XAM measures only the MCU
current while the peripherals are supplied directly by the
regulator. For this configurations place the jumper for
"I/O" (peripherals) into the "BYPASS" position and the "MCU"
into the "MEASURE" position.
- 3.Peripherals
measurement: The XAM measures only the
peripherals current while the MCU is directly supplied by
the regulator. For this configuration place the jumper for
"MCU" into the "BYPASS" position and the "I/O" jumper into
the "MEASURE" position.
- 4.MCU and
peripherals measurement: In this configuration
both MCU and peripherals are measured by the XAM. Place both
jumpers on "I/O" and "MCU" headers in the "MEASURE"
position.