A Comprehensive Model for Efficient Design Space Exploration of Imprecise Computational Blocks

After almost a decade of research, development of more efficient imprecise computational blocks is still a major concern in imprecise computing domain. There are many instances of the introduced imprecise components of different types, while their main difference is that they propose different precision-cost-performance trade-offs. In this paper, a novel comprehensive model for the imprecise components is introduced, which can be exploited to cover a wide range of precision-cost-performance trade-offs, for different types of imprecise components. The model helps to find the suitable imprecise component based on any desired error criterion. Therefore, the most significant advantage of the proposed model is that it can be simply exploited for design space exploration of different imprecise components to extract the suitable components, with the desired precision-cost-performance trade-off for any specific application. To demonstrate the efficiency of the proposed model, two novel families of Lowest-cost Imprecise Adders (LIAs) and Lowest-cost Imprecise Multipliers (LIMs) are introduced in the paper, which are systematically extracted based on exploration of the design space provided by the proposed model. A wide range of simulation and synthesis results are also presented in the paper to prove the comparable efficiency of the systematically extracted LIA/LIM structures with respect to the most efficient existing human-made imprecise components both individually and in a Multiply-Accumulate application.