Microchip Technology Power Debugger Manual page 30

Tip: The SAM L21 Xplained Pro also has integrated on-board current measurement features, but these
will not be used in this use case.
3.2.2 Initial Hardware Setup
A block diagram of the initial setup is shown here:
POWER DEBUGGER
host
host
3.2.3 Connections
Connect the kits according to the block diagram. Connections are described here:
To power the target: We will power the target from the variable voltage supply. This enables testing a USB device
over the full voltage range of the USB specification.
To do:
•
•
•
To measure the current drawn by the target MCU: the Xplained PRO board has a power 2-pin header next to the
TARGET USB connector. Usually a jumper is in place here connecting VCC_TARGET to VCC_MCU. By removing
this jumper and routing this circuit through a current measurement channel we can measure the current drawn only
by the MCU, and not the whole board.
To do:
•
•
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2020 Microchip Technology Inc.
DGI
IO0
IO1
USB
A
A
GND
B
A
TARGET
USB
Connect the variable voltage output to the input of the B channel using a strap cable. This enables us
to measure the total current drawn by the target.
Connect the output of the B channel to the POWER input of the USB type-A jack. This is simply done
by using a jumper.
Connect a USB cable from the type-A jack to the TARGET USB micro-jack
Connect VCC_TARGET on the target board to the input of the A channel
Connect the output of the A channel to the VCC_MCU pin of the target board
USB
TARGET
User Guide
Power Debugger
Detailed Use Cases
SWD
EXT1
GPIO0
GPIO1
DS40002201A-page 30