User guide

Parameter Dictionary
Word
Description
pass filters the firmware can only calculate a two pole filter. For these filter types,
bit 8 must be set.
2
This word gives the cut off frequency (in Hz) for low pass and high pass filters. For
notch and band pass filters this gives the first filter frequency.
3
This word gives the second filter frequency (in Hz) for notch and band pass filters.
4
Bits
Usage
0-7 Rp given in 0.1 dB units.
8-15 Rs given in dB units.
Rp is the pass band ripple. This parameter is only used for Chebychev and Elliptic
filters.
Rs is only used with elliptic filters. It defines the stop band as Rs dB down from
the peak value in the pass band.
5-6
Coefficient a1. All filter coefficients are passed as 32-bit IEEE floating point
numbers. The upper 32-bits should be passed first.
If the firmware designs the filter then the coefficients will be filled in by the
firmware and need not be passed.
7-8
Coefficient a2.
9-10
Coefficient b0.
11-12
Coefficient b1.
13-14
Coefficient b2.
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