Design and Implementation of IIR Filter by using Modified Wallace Tree Multiplier
A digital filters used in digital processor to perform numerical calculations on sampled values of the signal. The processor may be a general purpose computer such as a pc, or specialized digital signal processor chips. In signal processing, the function of a filter to remove unwanted part of the signal, such as random noise, or to extract useful part of the signal, such as the components lying within a certain frequency range. Here are two types of filters along and digital.IIR and FIR filters are the kind of filter digital filter, which can be used to perform all kinds of filtering i.e. high pass, low pass, band pass and band reject etc... The speed of operation is very important factor in digital signal processing (dsp).because of that the speed of IIR filter is also important. So the structure of IIR filters is replacing regular multiplier with modified Wallace tree multiplier to increase speed of operation and decrease power consumption. Multiplication is an important fundamental arithmetic operation in IIR filter. In this paper Conventional Array Multiplier and Dadda Multiplier are compared with the Wallace multiplier in terms of delay. Further a proposed sixteen bit IIR filter by using modified Wallace tree multiplier. Comparing to all multipliers only modified Wallace tree multiplier gives high speed. So this is used in IIR filter to enhance speed. These modified Wallace tree multipliers and IIR filter with this multiplier are coded in Verilog HDL, simulated and synthesized by using XILINX software 14.7 on Spartan 3E FPGA device xc3s500-5fg320
Keywords - Wallace tree multiplier, modified Wallace tree multiplier Proposed iir filter, Ripple Carry Adder (RCA), Carry Select Adder (CSLA), Binary to Excess Code Converter-1 (BEC-1).