EVAL-AD7470_15 Datasheet, PDF (9/20 Pages) Analog Devices – Evaluation Board for 10-/12-Bit High Speed, Low Power ADCs

The upper third of the dialog box contains the control buttons,
the menu bar, and the status windows. The control buttons
allow the user to take samples, reset the part, and quit the
program. The menu bar allows the user to enter the setup
menu, select which printer port is to be used to control the
EVAL-CONTROL BRD2, load and save data, and get informa-
tion about the software. The status window indicates the setup
of the evaluation board/device, the number of samples taken,
and any information or error messages are generated.
The middle third of the AD7470/AD7472 main dialog box is a
digital storage oscilloscope (DSO). When samples are uploaded
from the EVAL-CONTROL BRD2, they are displayed here. The
samples can be displayed either as integer values or as voltages.
Once the samples are displayed, clicking any point on the graph
displays the sample number and the value of the point directly
beneath the cursor. Along the axis of the graph are the zoom
handles; these allow you to zoom in and out to get a closer look
at a particular sample if required. When another set of samples
is taken the graph attempts to display all values collected unless
the Hold Zoom check box is ticked. If the Hold Zoom box is
ticked, the graph keeps the same axis settings as for the previous
set of data samples. There are additional check boxes in this
section to give you control over the vertical grids, horizontal
grids, and data points.
The lower third of the dialog box shows either a fast Fourier
transform (FFT) of the data, or a histogram, which shows the
number of occurrences of each particular code read back. The
FFT (the default option) is typically used when you are examin-
ing an ADC’s performance in the frequency domain, while the
histogram gives an indication of the ADC’s performance to DC
signals. The option displayed can be changed by clicking the
FFT Mode/Histogram Mode button in the top right of the
dialog box. Figure 5 shows the main dialog box when histogram
mode is selected.
Taking Samples
Clicking Sample instructs the EVAL-CONTROL BRD2 to take
the required number of samples at the required frequency from
the evaluation board. These samples are then uploaded and
displayed. An FFT and histogram are also calculated and
displayed. If you click Cont Samp, the software repeats the
process indefinitely until the user clicks the button Stop Samp.
While the software is continuously sampling data the other
control buttons are disabled.
EVAL-AD7470/AD7472
Reset Button
The Reset button causes the EVAL-CONTROL BRD2 to
perform a reset function. When this happens, the power
supplies are turned off and the program in DSP memory is
lost. Repeat the setup instructions to download another
program if required.
Quit Button
The Quit button exits the software. The program running on
the EVAL-CONTROL BRD2 is not terminated.
MENU BAR
The main dialog box of the EVAL-CONTROL BRD2 contains
a number of options available as pull-down menu items.
File Menu
Setup Menu: Displays the setup dialog box as shown in
Figure 3.
Load Raw Data: Allows the user to load data, which had been
saved by the software during a previous session.
Save Raw Data: Allows the user to save the current set of
sample data points. The data can be reloaded to the EVAL-
CONTROL BRD2 software at a later date or can be used by
other programs for further analysis.
Save Binary Data: Allows the user to save the current set of
sample data points. The data is saved in binary format as a text
file. This method can be useful for examining code flicker, and
looking for stuck bits.
Save FFT Data: Allows the user to save the current set of FFT
data points. FFT data cannot be reloaded into the EVAL-
CONTROL BRD2 software, but can be loaded into other
software packages for further analysis.
Exit: Quits the program.
Printer Port
This menu item allows you to select which printer port to use
for communicating with the EVAL-CONTROL BRD2.
LPT1: This option selects 0x378 as the printer port address.
This is the default option.
LPT2: This option selects 0x278 as the printer port address.
PRN: This option selects 0x3BC as the printer port address.
Help
This menu item gives information about the current revision of
software for the particular evaluation board being used.
Rev. C | Page 9 of 20