A FIR FILTER DEVICE FOR FLEXIBLE UP- AND DOWNSAMPLING

摘要

A FIR filter includes an input pipeline IP with a sequence of input delay cells DI;, each for storing an input sample, and a plurality of N input tap points TP;. An output pipeline includes a sequence of output delay cells DO;, each for storing a sample, a plurality of N summating elements Si for adding at least two samples, and an output switching network OSN for accumulating output values from the summating elements. A sequence of N taps T; are used for coupling the input pipeline to the output pipeline. Each tap includes a respective multiplier Mi for multiplying a sample from an input tap point by a coefficient. At least N-1 of the taps include a switching element for directing a sample from an input tap point through the multiplier to a summating element. The switching elements are arranged to enable supply of a sample from any tap point TPP to a summating element Si, where j <--i.