Fixed-point refinement of digital signal processing systems
Daniel Ménard, Gabriel Caffarena, Juan Antonio López Martín, David Novo, Olivier Sentieys · Institution of Engineering and Technology eBooks · 2019
For the digital signal processing (DSP) part of mixed-signal systems, fixed-point arithmetic is favoured due to its high efficiency in terms of implementation cost, namely energy consumption, area and latency. Fixed-point arithmetic provides low-cost operators at the expense of an unavoidable error between the ideal precision values and the finite precision ones. With a careful data word-length (WL) optimisation process, the designer can safely profit from the inherent trade-off between implementation cost and computation accuracy. In this chapter, we describe in detail the different stages comprising the fixed-point conversion process (i.e. dynamic range evaluation, WL optimisation, and accuracy evaluation) and propose practical solutions to address each stage.