Table‐Based Circuits for DSP Applications
Pramod Kumar Meher, Shen‐Fu Hsiao · 2017
This chapter provides a brief overview of the key concepts, important developments, implementations, and applications of some popularly used lookup table (LUT)-based computing systems. The most fundamental concept underneath the table-based computing systems is that if the desired results of computations could be stored in a memory unit, then instead of performing actual arithmetic operations the results could be retrieved directly from appropriate memory locations. LUTs can be used for the implementation of any Boolean function and which in turn can be used to realize any combinational unit for arithmetic operation or control logic. Two simple optimization techniques can be used to reduce the LUT size for constant multiplication. Those are: antisymmetric product coding (APC) scheme and odd multiple-storage (OMS) scheme. The chapter also discusses three LUT-based implementation of cyclic convolution and orthogonal transforms, evaluation of reciprocals, and evaluation of sigmoid functions.