Memory Design Techniques for Low Energy Embedded Systems

The proliferation of embedded systems, and the corresponding new chip and chip set designs, have brought additional attention to storage units. Indeed, the heterogeneity of components and structures within embedded systems and the possibility of using application-specific storage systems has added a new dimension to memory system design. Moreover, new degrees of freedom have been opened since the introduction of embedded memory arrays in different technologies, such as SRAMs, DRAMs and EEPROMs and Flash, and their realization on the same silicon substate hosting processing units. Embedded systems are often designed under stringent energy consumption budgets, to limit heat generation and battery size. Since memory systems consume a significant amount of energy to store and to forward data, it is then imperative to balance power consumption and performance in memory system design. Contemporary system design focuses on the trade off between performance and energy consumption in processing and storage units, as well as in their interconnections. While memory design is as important as processor design in achieving the desired design objectives, the former topic has received less attention than the latter in the literature. This text centres one of the most outstanding problems in chip design for embedded application. It guides the reader through different memory organizations and technologies and it reviews the most successful strategies for optimizing them in the power and performance plane.