DSP Blockset

Digital Filter Block

You can use the Digital Filter block to implement digital FIR and IIR filters in your models. Use this block if you have already performed the design and analysis and are able to provide the filter coefficients directly. You can use this block to filter single-channel and multichannel signals, and to simulate floating-point and fixed-point filters. You can use Real-Time Workshop to generate highly optimized C code from your filter block. For more information on generating C code from models, see Code Generation Support.

Required Parameters.   To implement a filter with the Digital Filter block, you must provide the following basic information about the filter:

• Whether the filter transfer function is FIR with all zeros, IIR with all poles, or IIR with poles and zeros
• The desired filter structure
• The filter coefficients

Note    Use the Digital Filter Design block to design and implement a filter. Use the Digital Filter block to implement a predesigned filter. Both blocks implement a filter design in the same manner and have the same behavior during simulation and code generation.

This section includes the following topics:

• Implementing a Lowpass Filter -- Create a lowpass filter using the Digital Filter block
• Implementing a Highpass Filter -- Create a highpass filter using the Digital Filter block
• Filtering High-Frequency Noise -- Build a system capable of filtering high-frequency noise using a highpass and lowpass filter

Filters

Implementing a Lowpass Filter