Design Techniques and Architectures for Low-Leakage SRAMs

In high performance Systems-on-Chip, leakage power consumption has become comparable to the dynamic component, and its relevance increases as technology scales. These trends are even more evident for memory devices, for two main reasons. First, memories have historically been designed with performance as the primary figure of merit; therefore, they are intrinsically non power-efficient structures. Second, memories are accessed in small chunks, thus leaving the vast majority of the memory cells unaccessed for a large fraction of the time. In this paper, we present an overview of the techniques proposed both in the academic and in the industrial domain for minimizing leakage power, and in particular, the subthreshold component, in SRAMs. The surveyed solutions range from cell-level techniques to architectural solutions suitable to system-level design.