DSP Builder: Half-Band Filter Using DSP Block & Time-Domain Multiplexing (TDM)
The design example describes an interpolation by two half-band filters with 79 taps (40 none-zero coefficients). Taking advantage of the symmetrical filter coefficients and the concept of time-domain multiplexing (TDM), the design requires only ten multipliers. The multipliers are implemented using DSP Blocks.
Download the files used in this example:
The use of this design is governed by, and subject to, the terms and conditions of the Altera Hardware Reference Design License Agreement.
Files in the zip download include:
- HBF_DSPBlock.mdl—DSP Builder design file implementing the interpolating half-band filter
- init.m—MATLAB script to initialize the sampling time, and simulation time and coefficients. The script also generates the stimuli: chirp and impulse.
Figure 1 shows the top-level diagram of the half-band filter design example in DSP Builder.
Figure 1. Half-Band Filter Top-Level Diagram

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Table 1 lists the ports and gives a description for each.
| Table 1. Half-Band Filter Port Listing |
| Port Name |
Type |
Description |
input_data[17:0] |
Input |
18-bit data inputs to complex multiplier unit |
clken |
Input |
Clock enable |
FirResult[37:0] |
Output |
38-bit data output of filter |
Related Links
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