Importing 8b ADC Data for Analysis in Wavevision5 and High Speed Data Converter Pro software tools

Importing with Wavevision5

Locating Data Files for easy import Copy the data files here: C:\Users\Public\Documents\National Semiconductor\WaveVision5\Data\Imports\

Open Wavevision5 – Pin Channel Tab Open

Click on Import Wavevision4 or Single/Double Column ASCII data file button (4th from left)

Import ASCII Data dialog box opens

Set desired Sampling Rate and Sample Width then click Import

Number of samples must be 2^n

Data is Imported to Time Domain Plot

Select FFT Plot

Unpin Channels Tab, pin FFT Readouts

Import another file, this time 25 MHz Fin

Truncated to 2^n samples

Resulting Time Domain plot

Resulting FFT – odd shape even though windowing is used

Check Time Domain Waveform – drag bottom scroll bar to view

Discontinuity in Waveform Causing bad FFT

Importing with HSDC Pro

Copy data to location below: Libraries\Documents

Launch HSDC Pro

Click Cancel on Select Board dialog

Click File>Import Data File

Select desired file

Select resolution – click OK

Initial view after import

Enter ADC Output Data Rate – 1500M

Change Test Selection to Time Domain

If waveform isn’t centered click Zoom All icon to right of plot window

HSDC Pro Import Data Processing Data file used for these examples is decimal representation of offset binary data from ADC08D1520 ADC HSDC Pro expects data centered around 0. For an 8 bit converter this corresponds to -128 to +127 Upon import HSDC Pro shifts this data to show sample values from 0 to 255 Since data imported was already from 0 to 255, the up-shifted version is centered around 255 instead of 128 The FFT results are still calculated properly