CDB5376 Datasheet, PDF (40/78 Pages) Cirrus Logic – Multichannel Seismic Evaluation System

CDB5376
3.3.2 Digital Filter
The Digital Filter sub-panel sets up the digital filter configuration options.
By default the Digital Filter sub-panel configures the system to use on-chip coefficients and test bit
stream data. The on-chip data can be overwritten by loading custom coefficients and test bit stream data
from the Customize sub-panel on the Control panel.
Any changes made under this sub-panel will not be applied to the target board until the Configure button
is pushed. The Configure button writes the new configuration to the target board and then enables the
data Capture button.
Control
Channel Set
Output Rate
Output Filter
FIR Coeff
IIR Coeff
Filter Clock
MCLK Rate
Configure
Description
Selects the number of channels that are enabled in the digital filter. For the CS5376A
digital filter, from 1 to 4 channels can be enabled.
Selects the output word rate of the digital filter. Output word rates from 4000 SPS to
1 SPS (0.25 mS to 1 S) are available.
Selects the output filter stage from the digital filter. Sinc output, FIR1 output, FIR2
output, IIR 1st order output, IIR 2nd order output, or IIR 3rd order output can be
selected. FIR2 output provides full decimation of the modulator data.
Selects the on-chip FIR coefficient set to use in the digital filter. Linear phase or min-
imum phase FIR coefficients can be selected.
Selects the on-chip IIR coefficient set to use in the digital filter. Coefficient sets pro-
ducing a 3 Hz high-pass corner at 2000 SPS, 1000 SPS, 500 SPS, 333 SPS, and
250 SPS can be selected.
Sets the digital filter internal clock rate. Lower internal clock rates can save power
when using slow output word rates.
Sets the analog sample clock rate. The CS5372 modulators and CS4373A test DAC
typically run with MCLK set to 2.048 MHz.
Writes all information from the Setup panel to the digital filter. The data Capture but-
ton becomes available once the configuration information is written to the target
board.
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