CDB5521/22/23/24/28
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Window - Used in the Power Spectrum
Window to calculate the FFT. Windowing
algorithms include the Blackman, Black-
man-Harris, Hand, 5-term Hodie, and 7-
term Hodie. The 5-term Hodie and 7-term
Hodie are windowing algorithms developed
at Crystal Semiconductor. If information
concerning these algorithms is needed, call
technical support.
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 col-
lected data set.
-
Average - Sets the number of consecutive
FFT’s to perform and average.
•
•
VARIANCE
Indicates the Variance for the current data set.
-
Limited Noise Bandwidth - Limits the
amount of noise in the converters band-
width. When set to zero, no limited noise
calculations are done.
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 can be used to print a hard
copy of that region. Click on RESTORE when
done with the zoom function.
-
FFT Bandwidth - Used in the Power Spec-
trum Window to allow user-scalability of
the frequency axis. When set to zero, the
axis is auto-scaled to one-half the output
word rate.
-
OK - Accept the changes
•
•
MAGNITUDE
Displays the y-axis value of the cursor on the
Histogram.
2.7 Frequency Domain Window (i.e. FFT)
MAXIMUM
The following describe the controls and indicators
associated with the Frequency Domain Analysis
(Figure 8).
Indicator for the maximum value of the collect-
ed data set.
•
•
MEAN
•
•
•
CANCEL
Indicator for the mean of the data sample set.
See description in Section 2.6, Histogram
Window Overview.
MINIMUM
Channel
Indicator for the minimum value of the collect-
ed data set.
See description in Section 2.6, Histogram Win-
dow Overview.
•
Output
COLLECT
Control that calls a pop-up menu. This menu
controls three options:
See description in Section 2.6, Histogram Win-
dow Overview.
1) save current data set to a file with the CDB-
CAPTURE format
DS317DB2
17
CIRRUS [ CIRRUS LOGIC ]
