DSP Blockset

Step 2 -- Design the Lowpass Filter and Select a Filter Structure.   

1. Double-click one of the Digital Filter Design blocks in the model to open the Filter Design and Analysis Tool (FDATool) GUI, shown in the following figure.
2. Set the block parameters as indicated in the following figure, and click Design Filter at the bottom of the GUI to design the filter.
3. Click the Magnitude Response button  to view the magnitude response of the filter as in the following figure. (You can explore the other buttons, which provide other filter analysis tools such as pole-zero plots and impulse response plots. Clicking the Filter Specification button  shows you the original display.)
4. Set the filter's structure in the Edit menu by selecting Convert Structure.... Set the structure to Direct form FIR transpose.

The block now implements a lowpass filter with a direct form FIR transpose structure. As the wpass and wstop settings indicate, the filter passes all frequencies up to 20% of the Nyquist frequency (half the sampling frequency), and stops frequencies greater than or equal to 50% of the Nyquist frequency.

Step 1 -- Get Necessary Blocks

Step 3 -- Design the Highpass Filter and Select a Filter Structure