EVAL-AD7492CB

–6–

REV. A

Figure 2. Main Screen

SOFTWARE DESCRIPTION

The software which controls the Evaluation Board Controller

and hence the evaluation board has three main screens.

The screen shown in Figure 2 shows the screen which appears

when the software is run. The main function of this screen is

to allow the user to read a predetermined number of samples

from the evaluation board and display them in both the time

and frequency domain. The screen can be divided into 3

sections. The upper third of the screen contains the control

buttons, the menu bar and various status windows. The

control buttons allow the user to enter the setup menu, take

samples and get information about the software. The menu

bar allows the user to select which printer port is to be used

to control the Evaluation Board Controller, load and save

data etc. The status windows indicate the setup of the

evaluation board/device, number of samples taken and any

information/error messages that are generated.

The middle third of the screen is a Digital Storage Oscilloscope

(DSO). When samples are uploaded from the Evaluation

Board Controller they are displayed here. The samples can be

displayed either as integer values or as voltages (determined

by the input range of the device inquestion). Once samples

have been displayed clicking at any point in the graph will

display the sample number and value of the point directly

beneath the cursor. Along the axis of the graph are the “zoom

handles”. These allow the user 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 will attempt to display all

values collected unless the Hold Zoom check box is ticked.

In this case the graph will keep the same axis settings as for

the previous set of data samples. Additional check boxes are

provided to give the user control over the vertical and

horizontal grids and data points. The lower third of the screen

will show either a Fast Fourier Transform (FFT) of the data

or a Histogram which shows the number of occurrances of

each particular code read back. The FFT (the default option)

is typically used when the user is concerned with examining

an ADC’s performance in the frequency domain while the

Histogram will give an indication of the ADC’s performance

to DC signals. The option displayed can be toggled by

clicking on the FFT Mode/Histogram Mode button in the

top right of the screen. Figure 3 shows how the main screen

looks when the Histogram Option is selected.