Dynamic register-renaming scheme for reducing power-density and temperature

The manufacturing process of microprocessors becomes increasingly fine and the clock frequency is rapidly growing. Since the corresponding power consumption, however, is not reduced, the power density is increased dramatically. The high temperature and heat generated by the power density causes many problems: malfunction, aging, leakage power and cooling costs. The register file produces the highest temperature in the microprocessor because of extremely high access frequency and its small area. We demonstrated that the traditional renaming unit causes high temperature since it allocates registers imbalanced. Our idea is to redistribute evenly register allocations and accesses across the full range of the register file; consequently, the overall power density is lowered and then the temperature is reduced. The proposed method can be implemented by adding a small logic to the traditional renaming unit with around 1.5% overheads. The results are as follows. Temperature drop was up to 11% on average 6%; leakage power saving was up to 24% on average 13%; performance improvement was up to 103% on average 84%.