Ultralow-Energy Variation-Aware Design: Adder Architecture Study

Power consumption of digital systems is an important issue in nanoscale technologies and growth of process variation makes the problem more challenging. In this brief, we have analyzed the latency, energy consumption, and effects of process variation on different structures with respect to the design structure and logic depth to propose architectures with higher throughput, lower energy consumption, and smaller performance loss caused by process variation in application-specific integrated circuit design. We have exploited adders as different implementations of a processing unit, and propose architectural guidelines for finer technologies in subthreshold which are applicable to any other architecture. The results show that smaller computing building blocks have better energy efficiency and less performance degradation because of variation effects. In contrast, their computation throughput will be mid or less unless proper solutions, such as pipelined or parallel structures, are used. Therefore, our proposed solution to improve the throughput loss while reducing sensitivity to process variations is using simpler elements in deep pipelined designs or massively parallel structures.