Altera FIR Compiler - Manual (Page 28)

3–4 Chapter 3: Parameter Settings
Specifying the Coefficients
FIR Compiler User Guide © May 2011 Altera Corporation
3. After making your settings, click Apply. The dialog box displays the frequency
response of the filter in blue and also displays a list of the actual coefficient values.
(
Figure 3–3 ).
4. To generate floating-point coefficients for interpolation or decimation rate filters,
select Interpolation or Decimation and the required Factor from the Rate
Specification
drop-down boxes.
When you click Auto Generate, IP Toolbench generates coefficients for a low-pass
filter with a cutoff frequency based on the specified rate.
Figure 3–4 on page 3–5 shows a decimation filter. The cut-off frequency is ¼ of the
sampling rate and results in a half-band coefficient set.
For an explanation of interpolation and decimation, refer to “Interpolation and
Decimation” on page 4–8 .
Figure 3–3. Parallel FIR Filter Coefficient Parameters for Band Pass Filter