Configurable low-power arrays for real-time recursive filtering

This paper explains how a linear array of a fixed number of multiply-accumulate modules may be configured for real-time recursive filtering over a wide range of sample rates, by trading the latter for filter order. This is effected by projecting the computations of multiple recursive and nonrecursive multiply-accumulate operations in infinite impulse response filtering for example, onto one physical multiply-accumulate module. These projected multiply-accumulate operations are scheduled-in the same sample period using a system clock that is faster than the sample clock by a factor that equals the projection order, so that the resulting structure is maximally efficient. The projection order (hence the system clock rate) is made configurable, and the supply voltage autoregulates correspondingly so that the system operates economically in respect of the power dissipated