3.2.
Xplained Pro Analog Module (XAM)
3.2.1.
Overview
The Xplained Pro Analog Module (XAM) extends the embedded debugger with high dynamic range
current measurement. This enables power profiling of the target system.
ADC0
ADC1
20x
voltage
reference
2.7V
Control MCU
GND
S&H
ADC
Calibration
circuitry
Calibration ON/OFF
AREF
GPIO
GPIO(s)
GPIO
100 mOhm
100 Ohm
EDBG
SPI
Clock sync
SWD
Sync
GPIO
I2C
2x
16x
Current input
Current output
Range selection
Pre-amplifier
Active filter with
gain
Xplained Pro Analog Module (XAM)
20x
The XAM consists of:
•
Calibration circuitry
•
Voltage reference
•
Analog frontend
–
Shunt resistors with a range selection switch
–
Pre-amplifier
–
Two active filters with gain
•
Control MCU
–
Analog to digital converter
–
Signal processing
–
Control/communication interface to the EDBG
The current measurement frontend is a high side shunt measurement with a pre-amplifier and a second
active filter stage with gain. The wide dynamic range is achieved by four measurement ranges which are
defined by two shunts and the two parallel second stage active filters with gain.
3.2.2.
EDBG Interface
The Xplained Pro Analog Module (XAM) is connected to the EDBG with the following interfaces:
•
I
2
C: This is used to control and configure the XAM
•
SPI: Current measurement data is streamed to the EDBG via this interface. This is a one-way data
transfer channel from the XAM to the EDBG
Atmel SAM L22 Xplained Pro [USER GUIDE]
Atmel-42474B-SAM-L22-Xplained-Pro_User Guide-12/2015
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