IPR-FIR Altera, IPR-FIR Datasheet - Page 51

• Manufacturer Part Number: IPR-FIR
• Description: IP CORE Renewal Of IP-FIR
• Manufacturer: Altera
• Type: MegaCorer

Specifications of IPR-FIR

• Software Application: IP CORE, DSP Filters And Transforms
• Supported Families: Arria GX, Arria II GX, Cyclone, HardCopy, Stratix
• Core Architecture: FPGA
• Core Sub-architecture: Arria, Cyclone, Stratix
• Rohs Compliant: NA
• Function: Finite Impulse Response Compiler
• License: Renewal License
• Lead Free Status / RoHS Status: na
• Lead Free Status / RoHS Status: na

Chapter 4: Functional Description
FIR Compiler
© December 2010 Altera Corporation
Mathematically, when a signal is interpolated, zeros are inserted between data points
and the data is then filtered to remove spectral components that were not present in
the original signal
Figure 4–7. Signal Interpolation
To decimate a signal, a low-pass filter is applied, which removes spectral components
that will not be present at the low sample rate. After filtering, appropriate sample
values are taken
Figure 4–8. Signal Decimation
The FIR Compiler generates interpolation and decimation filters by combining high-
and low-level optimization techniques.
Using the high-level optimization technique, the FIR Compiler processes the data
from a polyphase decomposed filter. The polyphase decomposition breaks a single
filter into several smaller filters, which results in the following:
■
■
Using the low-level optimization technique, the polyphase decomposed filter is
implemented using a multichannel, multiple coefficient set structure with an
appropriate wrapper.
When using an interpolation filter, zero-stuffed data does not need to be
computed; potentially saving resources
When using a decimation filter, output data—which is discarded during
downsampling—is never computed, again potentially saving resources
(Figure 4–10 on page
(Figure
(Figure
4–8).
4–11).
Input
Input
4–7).
Input
Data
Decimated
Data
Filtered
Data
After
Low-Pass
Filtering
Input
Data
After
Zero
Stuffing
LPF
N
(Figure 4–9 on page
LPF
M
Output
Output
4–10).
FIR Compiler User Guide
4–9