CDB5461 Datasheet, PDF (16/27 Pages) Cirrus Logic – Evaluation Board and Software

CDB5461
two channels, and 2048 samples when collect-
ing three channels.
2.9.2 Average
When doing FFT processing, this box will de-
termine the number of FFTs to average. FFTs
will be collected and averaged when the Col-
lect button is pressed.
2.9.3 FFT Window
This box allows the user to select the type of
windowing algorithm for FFT processing. Win-
dowing algorithms include the Blackman,
Blackman-Harris, Hanning, 5-term Hodie, and
7-term Hodie. The 5-term Hodie and 7-term
Hodie are windowing algorithms developed at
Crystal Semiconductor.
2.9.4 Histogram Bin Width
This box allows for a variable "bin width" when
plotting histograms of the collected data. Each
vertical bar in the histogram plot will contain
the number of output codes contained in this
box. Increasing this number may allow the
user to view histograms with larger input rang-
es.
2.9.5 Pages to Collect
This box determines the number of data "pag-
es" that the microcontroller will collect before
sending data to the PC. Each page consists of
the number of samples collected, and only the
last page will be returned to the PC for pro-
cessing. This function is useful at higher sam-
pling frequencies to minimize board-level
noise at the beginning of the conversion set.
Figure 6. Time Domain Analysis
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