This book introduces new algorithms and methodologies for the approximation
synthesis problem. The evaluations of these methodologies are carried out on a
wide range circuits. The proposed algorithms are effective and scalable and come
with a formal guarantee on the error metrics.
In this book, we propose the design automation techniques for the synthesis, verification, and test of an approximate hardware design. Nevertheless, the approximate computing paradigm is not limited to the underlying hardware alone. Naturally, the software can also perform standalone approximations without involving the
hardware. However, in several cases, a cross-layer approximate computing strategy
involving both the hardware and the software level approximations is the most
beneficial for performance [VCC+13, YPS+15]. This brings out the best of both
worlds. We dedicate the final chapter of this book to such cross-layer approximation
architectures.
Each chapter in this book focuses on one main contribution towards the realization of a high performance approximate computing systems, answering several of the major questions outlined earlier. An approximate computing IC design
flow is not radically different from a conventional one. However, there are some
important modifications and additional steps needed to incorporate the principles of
approximate computing. An overview of the approximate computing IC design flow
along with the important contributions in this book is given next