EMPIRE: Empirical power/area/timing models for register files

With the growth of the embedded devices consumer market, power efficient hardware is needed. Therefore power-aware architectural exploration is one of the most crucial design steps. For such an exploration procedure, it is important to accurately model the power consumption of all main components of the embedded system. Registers and register files are one of the highest power consumers of any programmable processor, but there is a lack of accurate and publicly available models. This paper provides such a power model for standard cell based register files for 130 and 90 nm technologies. The proposed model provides dynamic power, leakage power, area and timing information for register files in terms of key parameters like width, depth, activity, ports, and capacitive loading. It is shown that current models capture neither correct absolute nor relative trends present in register files. It is shown that some key, but often neglected parameters like switching activity, load have a larger influence in some particular sizes of the register files than others. Therefore, using the Empire model, accurate architectural exploration is possible.