Table of Contents
VLSI Design
Volume 10, Issue 2, Pages 177-202

Computation Reordering: A Novel Transformation for Low Power DSP Synthesis

VLSI Design Laboratory, Department of Electrical and Computer Engineering, University of Patras, Rio 26500, Greece

Received 13 April 1998; Accepted 21 June 1998

Copyright © 1999 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A novel architectural transformation for low power synthesis of inner product computational structures is presented. The proposed transformation reorders the sequence of evaluation of the multiply-accumulate operations that form the inner products. Information related to both coefficients, which are statically determined, and data, which are dynamic, is used to drive the reordering of computation. The reordering of computation reduces the switching activity at the inputs of the computational units but inside them as well leading to power consumption reduction. Different classes of algorithms requiring inner product computation are identified and the problem of computation reordering is formulated for each of them. The target architecture to which the proposed transformation applies is based on a power optimal memory organization and is described in detail. Experimental results for several DSP algorithms show that the proposed transformation leads to significant savings in net switching activity and thus in power consumption.