Implementation of IIR

There are many different structures for realizing digital IIR filters, and we need to understand and determine a suitable arrangement for a particular application. The factors to be considered include errors in quantizing filter coefficients, noise introduced by fixed-point arithmetic, propagation of quantization errors, computational load, memory usage, and programming consideration and flexibility. In this section, we examine the following commonly used IIR filter structures:

Direct form I

Direct form II

Cascade form

Parallel form

Transposed direct form I

Transposed direct form II