Xilinx AMS101 User Manual page 42

Chapter 4: AMS Evaluator Tool
memory, the data is transferred to the AMS Evaluator tool through the USB-UART
connection. The AMS Evaluator tool then does a mean, minimum, maximum, and
standard deviation calculation on the data before displaying it. In the case of simultaneous
sampling mode, 8,192 XADC results are taken, 4,096 for V
AMS Evaluator tool receives all 8,192 pieces of data in one array and splits it appropriately.
The tool then does a mean, minimum, maximum, and standard deviation calculation
separately on V
side in a dual display. The mean, minimum, maximum, and standard deviation calculation
results are shown below the graph of the XADC samples.
Frequency Domain
The Frequency Domain tab enables an FFT on the XADC data. Similar to the time domain
data collection, 4,096 sequential XADC results for V
mode and 4,096 XADC results of V
simultaneous sampling mode. An FFT is then performed on this data and key ADC
dynamic performance metrics are calculated and displayed. These metrics include signal
to noise ratio (SNR), total harmonic distortion (THD), signal to noise and distortion
(SINAD), spurious free dynamic range (SFDR), and effective number of bits (ENOB).
If the signal source is not the DAC on the evaluation card, then windowing is carried out
on the XADC data before the FFT is performed. This is because the external source might
or might not be a coherent source. The windowing method can be changed by adjusting
the pull-down menu shown in
Blackman-Harris window, and five bins on either side of the fundamental are discarded in
the SNR calculation.
X-Ref Target - Figure 4-6
42
and V data. The V
AUX0 AUX8
and 4,096 XADC results of V
AUX0
Figure 4-6. By default, it is set to a fourth order
Windowing Method Number of Bins Ignored in
Employed
Figure 4-6: Windowing Options
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and 4,096 for V
AUX0
and V data is then displayed side by
AUX0 AUX8
/ V are taken when in single channel
P N
SNR Calculation
AMS101 Evaluation Card User Guide
UG886 (v1.3) November 6, 2013
. The
AUX8
are taken in
AUX8
UG886_c4_06_092512