Approaches to Low-Power Implem

Abstract—Reduc tion of power consumption is signif icantly
imp ortant for all high-pe rformance digital VLSIsystems. This
paper reviews several appro aches for low-power implementations
of building blocks for digital subscriber line (DSL) systems.
Low-power implementations of Reed–Solomon ( RS) coders,
fast Fourier transforms (FFTs), FIR fil ters, and equalizers, and
reduction of power consumption by use of dual supply voltages
are addressed. It is shown that use of separate Galois Field
functional units for multiply-accumulate and degree reduction
canreduce the energy consumption of RS coders dramatically.
A hybrid feedforward and feedback commutator scheme-based
FFT is shown to require less area and full hardware utilization
efficiency. Reduction of switching activity at one or both inputs of
the multipliers is a key to reduction of power consumption in FIR
filters and equalizers. The switching activity can be reduced by use
of transpose structure and by time-multiplexing of an unfolded
filter. A well established retiming approach can be generalized
to find those noncritical gates which can be operated with lower
supply voltages to reduce the overall system power consumption.