Ultra-Efficient (Embedded) SOC Architectures based on Probabilistic CMOS

Major impediments to technology scaling in the nanometer regime include power (or energy) dissipation and “erroneous” behavior induced by process variations and noise susceptibility. In this paper, we demonstrate that CMOS devices whose behavior is rendered probabilistic by noise (yielding probabilistic CMOS or PCMOS) can be harnessed for ultra low energy and high performance computation. PCMOS devices are inherently probabilistic in that they are guaranteed to compute correctly with a probability 1/2 < p < 1 and thus, by design, they are expected to compute incorrectly with a probability (1 − p). In this paper, we show that PCMOS technology yields significant improvements, both in the energy consumed as well as in the performance, for probabilistic applications with broad utility. These benefits are derived using an application-architecture-technology (AT) co-design methodology introduced here, yielding an entirely novel family of probabilistic system-on-a-chip (PSOC) architectures. All of our application and architectural savings are quantified using the product of the energy and the performance denoted (energy × performance): the PCMOS based gains are as high as a substantial multiplicative factor of over 560 when compared to a competing energy-efficient CMOS based realization.