Static Minimization of Total Energy Consumption in Memory Subsystem for Scratchpad-Based Systems-on-Chips

In VLSI systems-on-chips (SoC), leakage is expected to override 50% of the total power consumption, and the memory sub-system can be responsible for up to 75% of the power. Scratch-pad memories (SPM) are a proven alternative to cache memories in power-aware SoCs. Optimal SPM mapping has already been investigated for dynamic power reduction in the main memory and for leakage reduction in the SPM itself. This paper addresses the problem of global energy optimization (i.e., active + leakage) in the whole memory sub-system of an SPM-based SoC. We focus on SPMs dedicated to instructions and constant data. We present the technology-level foundation, the mathematical problem formulation, its solution as an integer-linear-programming (ILP) problem, the implemented design flow, and the power reduction results referring to standard benchmarks and ITRS technology data.