Cirrus Logic CDB5529 - Manual (Page 10)

CDB5529
10 DS246DB1
Histogram Window Overview
The following is a description of the controls and in-
dicators associated with the Histogram Window.
Many of the control icons are usable from the Histo-
gram Window, the Frequency Domain Window, and
the Time Domain Window. For brevity, they are
only described in this section.
BIN: Displays the x-axis value of the cursor on the
Histogram.
CANCEL: Once selected, it allows a user to exit
from the COLLECT algorithm. If data conversion
sample sets larger than 64 are being collected and
the CANCEL button is selected, it is recommended
that the user reset the evaluation board. The board
will eventually recover from the continuous collec-
tion mode, but the recovery time could be as long
as 10 minutes.
COLLECT: Initiates the data conversion collec-
tion process. COLLECT has two modes of opera-
tion: collect from file or collect from converter. To
collect from a file an appropriate file from the SET-
UP-DISK menu bar option must be selected. Once
a file is selected, its content is displayed in the
graph. If the user is collecting real-time conver-
sions to analyze, the appropriate COM port must be
selected. The user is then free to collect the preset
number of conversions (preset by the CONFIG
pop-up menu discussed below). Notice, there is a
significant acquisition time difference in the two
methods.
CONFIG: Opens a pop-up panel to configure how
much data is to be collected, and how to process the
data once it is collected. The following are controls
and indicators associated with the CONFIG panel.
SAMPLES: User selection of 64, 256, 512, 1024,
2048, 4096, or 8192 conversions.
WINDOW: Used in the Power Spectrum Window
to calculate the FFT. Windowing algorithms in-
clude the Blackman, Blackman-Harris, Hanning,
5-term Hodie, and 7-term Hodie. The 5-term Hod-
ie and 7-term Hodie are windowing algorithms de-
veloped at Crystal Semiconductor. If information
concerning these algorithms is needed, call techni-
cal support.
AVERAGE: Sets the number of consecutive FFT’s
to perform and average.
LIMITED NOISE BANDWIDTH: Limits the
amount of noise in the converters bandwidth. De-
fault is 0 Hz.
OK: Accept the change
MAGNITUDE: Displays the y-axis value of the
cursor on the Histogram.
MAXIMUM: Indicator for the maximum value of
the collected data set.
MEAN: Indicator for the mean of the data sample set.
MINIMUM: Indicator for the minimum value of
the collected data set.
OUTPUT: Control that calls a pop-up menu. This
menu controls three options: 1) save current data
set to a file with the CDBCAPTURE format, 2)
print current screen, or 3) print current graph.
RESTORE: Restores the display of the graph after
zoom has been entered.
STD. DEV.: Indicator for the Standard Deviation
of the collected data set.
TEST: Quick access control icon, similar to the hot
keys, to allow user to quickly switch between a time
domain, a frequency domain, or a histogram display.
VARIANCE: Indicates the Variance for the cur-
rent data set.
ZOOM: Control icon that allows the operator to
zoom in on a specific portion of the current graph.
To zoom, click on the ZOOM icon, then click on the
graph to select the first point (the 1st point is the top
left corner of the zoom box). Then click on the
graph again to select the second point (the 2nd point
is the bottom right corner of the zoom box). Once an
area has been zoomed in to, the OUTPUT functions