Leakage Power Optimization Techniques for Ultra Deep Sub-Micron Multi-Level Caches

On-chip L1 and L2 caches represent a sizeable fraction of the total power consumption of microprocessors. In deep sub-micron technology, the subthreshold leakage power is becoming the dominant fraction of the total power consumption of those caches. In this paper, we present optimization techniques to reduce the leakage power of on-chip caches assuming that there are multiple threshold voltages, VTH’s, available. First, we show a cache leakage optimization technique that examines the trade-off between access time and leakage power by assigning distinct VTH's to each of the four main cache components — address bus drivers, data bus drivers, decoders, and SRAM cell arrays with sense-amps. Second, we show optimization techniques to reduce the leakage power of L1 and L2 on-chip caches without affecting the average memory access time. The key results are: 1) 2 VTH's are enough to minimize leakage in a single cache; 2) if L1 size is fixed, increasing the L2 size can result in ...

• Type: Conference
• Year: 2003
• Where: ICCAD
• Authors: Nam Sung Kim, David Blaauw, Trevor N. Mudge
• Keywords: Cache Leakage Optimization, Hardware, ICCAD 2003, Leakage Power, Subthreshold Leakage Power