The Digital Filter Design tool for the dsPIC^®16-bit Digital Signal Controllers makes designing, analyzing and implementing Finite Impulse Response (FIR) and Infinite Impulse Response (IIR) digital filters easy through a menu-driven and user intuitive interface. The filter design tool performs complex mathematical computations for filter design, provides superior graphical displays and generates comprehensive design reports. Desired filter frequency specifications are entered and the tool automatically generates the filter code and coefficient files ready to use in the MPLAB® IDE.System analysis of the filter transfer function is supported with multiple generated graphs such as: magnitude, phase, group delay, log magnitude, impulse response and pole/zero locations.

Features

Key features of the Digital Filter Design tool include:
Finite Impulse Response Filter Design
• Design Method Selection
– FIR Windows Design
– FIR Equiripple Design (Parks-McClellan)
• Lowpass, Highpass, Bandpass and Bandstop filters
• FIR filters can have up to 513 taps
• Following window functions are supported:
– Rectangular
– Hanning (Hann)
– Hamming
– Triangular
– Blackman
– Exact Blackman
– 3 Term Cosine
– 3 Term Cosine with continuous 3rd Derivative
– Minimum 3 Term Cosine
– 4 Term Cosine
– 4 Term Cosine with continuous 5th Derivative
– Minimum 4 Term Cosine
– Good 4 Term Blackman Harris
– Harris Flat Top
– Kaiser
– Dolph-Tschebyscheff
– Taylor
– Gaussian
• Reports show design details such as window
coefficients and Impulse Response prior to multiplying
by the window function

Infinite Impulse Response Filter Design

• Lowpass, Highpass, Bandpass and Bandstop Filters
  • Filter orders up to 10 for Lowpass and Highpass
  Filters
  • Filter orders up to 20 for Bandpass and Bandstop
  Filters
  • Five Analog Prototype Filters are available:
  – Butterworth
  – Tschebyscheff
  – Inverse Tschebyscheff
  – Elliptic
  – Bessel
  • Digital Transformations are performed by Bilinear
  Transformation Method
  • Reports show design details such as all
  transformations from normalized lowpass filter to
  desired filter

Code Generation Features

• Generated files are compliant with the Microchip
  MPLAB^® C30 Compiler, Assembler and Linker for dsPIC DSCs
  • Choice of placement of coefficients in Program Space
  or Data Space
  • C wrapper/header code generation

Graphs

• Magnitude Response vs. Frequency
  • Log Magnitude vs. Frequency
  • Phase Response vs. Frequency
  • Group Delay vs. Frequency
  • Impulse Response vs. Time (per sample)
  • Step Response vs. Time (per sample)
  • Pole and Zero Locations (IIR only

Host System Requirements

• PC-compatible system with an Intel Pentium®class or higher processor, or equivalent
  • A minimum of 16 MB RAM
  • A minimum of 40 MB available hard drive space
  • CD ROM drive
  • Microsoft Windows®98, Windows 2000, Windows XP or Windows NT®