CDB5461 Datasheet, PDF (18/27 Pages) Cirrus Logic – Evaluation Board and Software

CDB5461
2.9.6 Data to Collect
These six check boxes allow the user to select
the data channels that will be collected and re-
turned to the PC for processing. Up to three
channels can be selected at once. There are
some restrictions on the speed and number of
samples to collect when selecting more than
one channel. A warning message will appear
on pressing the Collect button in the Data Col-
lection Window if any speed limits appear to be
exceeded, but the data collection will still take
place.
2.9.7 Accept Button
When this button is pressed, the current set-
tings will be saved, and the user will return to
the Data Collection Window.
2.10 Collecting Data Sets
To collect a sample data set:
1) In the Data Collection Window, press the
Config button to bring up the Configuration
Window and view the current settings.
2) Select the appropriate settings from the
available options (see the section on the
Configuration Window) and press the Ac-
cept button.
3) The Data Collection Window should still be
visible. Press the Collect button to begin
collecting data. A progress indicator bar
will appear at the bottom of the screen dur-
ing the data collection process.
4) Data is first collected from the CS5461 and
stored in SRAM, and then transferred from
the SRAM to the PC through the RS-232
serial cable. Depending on the value of the
Cycle Count Register and the number of
samples being collected, this process may
take a long time. The process can be termi-
nated by pressing the Stop button, but if
this is done, the user should also press Re-
set on the CDB5461 board.
5) Once the data has been collected, it can be
analyzed, printed, or saved to disk.
2.11 Retrieving Saved Data From a File
The CDB5461 software allows the user to
save data to a file, and retrieve it later when
needed. To load a previously saved file:
1) Pull down the Setup option and select Disk.
A file menu will appear.
2) Find the data file in the list and select it.
Press the Select button to return.
3) Go to the Data Collection Window, and
press the Collect button.
4) The data from the file should appear on the
screen. To select a different file, repeat the
procedure.
2.12 Analyzing Data
The evaluation software provides three types
of analysis tests: Time Domain, Frequency
Domain, and Histogram. The Time Domain
analysis processes acquired conversions to
produce a plot of Magnitude versus Conver-
sion Sample Number. The Frequency Domain
analysis processes acquired conversions to
produce a magnitude versus frequency plot
using the Fast-Fourier transform (results up to
Fs/2 are calculated and plotted). Also, statisti-
cal noise calculations are calculated and dis-
played. The Histogram analysis test
processes acquired conversions to produce a
histogram plot. Statistical noise calculations
are also calculated and displayed.
2.13 Histogram Information
The following is a description of the indicators
associated with Histogram Analysis. Histo-
grams can be plotted in the Data Collection
Window by setting the Time Domain / FFT / His-
togram selector to Histogram (Figure 8).
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