Sung Woo Chung and Kevin Skadron, "On-demand solution to minimize I-cache leakage energy with maintaining performance", IEEE Transactions on Computers, vol. 57, no. 1, pp. 7-24, January 2008.
Abstract
This paper describes a new on-demand wake-up prediction policy for
reducing leakage power. The key insight is that branch prediction can be
used to selectively wake up only the needed cache line. This achieves
better leakage savings than the best prior policies while avoiding the
performance overheads of those policies, without needing an extra
prediction structure. The proposed policy reduces leakage energy by 92.7
percent with only 0.08 percent performance overhead on average. The
branch-prediction-based approach requires an extra pipeline stage for
wake up, which adds to the branch misprediction penalty. Fortunately,
this cost is mitigated because the extra wake-up stage is overlapped
with misprediction recovery. This paper assumes the superdrowsy leakage
control technique using reduced supply voltage because it is well suited
to the instruction cache's criticality. However, the proposed policy
can be also applied to other leakage-saving circuit techniques.