CDB5471 Datasheet, PDF (18/26 Pages) Cirrus Logic – Evaluation Board and Software

CDB5471
3.2.4.2. Time Domain / FFT / Histogram
Selector
This selector button is located just to the right of the
Collect Button. The label on this button will
change as the user selects which analysis is to be
performed (“Time Domain” or “FFT” or “Histo-
gram”). When the software is first started, the de-
fault mode on this selector button is Time Domain.
This user should click on this button to select which
type of data processing to perform on the collected
data and display in the plot area. Refer to the sec-
tion on Analyzing Data for more information.
3.2.4.3. “Crystal” Value Indicator Box
The value in this box reflects the frequency of the
CS5451’s clock input (at the XIN pin). Since the
XIN frequency affects the sampling rate (the output
word rate) of the CS5451, this information must be
specified to the software so that it can accurately
depict the frequency-content of the sampled data
(in Hz) when performing an FFT analysis. The
user can enter the crystal frequency that is used on
the CDB5451 board into this box. The default val-
ue of this box is set for the on-board 4.096MHz os-
cillator.
3.2.4.4. OWRS Pin Setting:
This switch should be adjusted whenever the user
toggles the S1-1 DIP switch (on the evaluation
board). The default setting of this switch is HI, cor-
responding to the default setting on S1-1 (default
setting is “OPEN”). S1-1 drives the CS5471’s
OWRS pin to logic “1”. A logic “1” on OWRS sets
the sampling frequency of both CS5471 input
channels to XIN/1024. To toggle the state of the
on-screen switch, simply click on the switch with
the mouse.
3.2.4.5. Config Button
This button will bring up the configuration window
(shown in Fig 7) in which the user can modify the
data collection specifications. See the discussion
of the Config Window in this document.
3.2.4.6. Save Button
The red-colored SAVE button will save the data in
the current plot to a file. The exact path and filena-
me can be specified by the user in the text window
located just to the left of the SAVE button. The
data collected for both channels will be saved to a
text file.
3.2.4.7. Load Button
The green colored LOAD button will load any data
file that was previously generated by clicking on
the red SAVE button. The exact path and filename
must be specified by the user in the text window lo-
cated just to the left of the LOAD button.
3.2.4.8. Channel Selector Buttons
Clicking on buttons labeled as “V1” and “I1” will
display a certain channel of data. “V1” refers to the
voltage data taken across the Vin1+/Vin1- pins of
the CS5471. In a similar manner, clicking on the
“I1” button will display the data representing the
voltage level across the current channel input pins
(Iin1+/Iin1-).
3.2.5 Config Window
See Figure 7. Clicking on the Config button will
bring up a small pop-up window called the Config
Window. The Config Window allows the user to
set up the data collection and analysis parameters,
which are described next.
3.2.5.1. Number of Samples
This box allows the user to select the number of
samples to collect. The user can choose any whole-
number power of 2 between 16 and 32768.
3.2.5.2. Average
When performing FFT processing, this box will de-
termine the number of FFTs to average. FFTs will
then be collected and averaged when the user clicks
on the Collect Button.
18
DS480DB1