An Energy-Aware Architectural Exploration Tool for ARM-Based SOCs

In recent years, power consumption has become a critical concern for many VLSI systems. Whereas several case studies demonstrate that technology-, layout-, and gate-level techniques offer power savings of a factor of two or less, architecture and system-level optimization can often result in orders of magnitude lower power consumption. Therefore, the energy-efficient design of portable, battery-powered systems demands an early assessment, i.e., at the algorithmic and architectural levels, of the power consumption of the applications they target. Addressing this issue, we developed an energy-aware architectural design exploration and analysis tool for ARM based system-on-chip designs. The tool integrates the behavior and energy models of several user-defined, custom processing units as an extension to the cycle-accurate instructionlevel simulator for the ARM low-power processor family, called the ARMulator. The models we implemented take into account the particular class, e.g., datapath, memory, control, or interconnect, as well as the architectural complexity of the hardware unit involved and the signal activity triggered by the specific algorithm executed on the ARM processor. Our tool can estimate at the architectural level of detail the overall energy consumption or can report the energy breakdown among different units. Preliminary experiments indicated that the estimation accuracy is within 25% of what can be accomplished after a circuit-level simulation on the laid-out chip. Keywords— ARM CPU core; system-on-chip; ARMulator; energy-aware architectural exploration; batterypowered system.