基于统计信息的Cache漏流功耗估算方法

随着工艺尺寸的缩小,漏流功耗逐渐成为制约微处理器设计的主要因素之一.Sleep Cache与Drowsy Cache是两种降低Cache漏流功耗的重要技术.基于统计信息的Cache漏流功耗估算方法(SB-CLPE)用于对Sleep Cache或Drowsy Cache进行Cache漏流功耗估算,根据该方法设计的Cache体系结构能够在程序执行过程中实时估算Cache漏流功耗.通过对所有Cache块的访问间隔时间进行统计,SB_CLPE可以估算出使用不同衰退间隔时Cache的漏流功耗,从而得到使Cache漏流功耗最低的最佳衰退间隔.实验表明,SB_CLPE对Sleep Cache的漏流功耗的估算结果与HotLeakage漏流功耗模拟器通过模拟获得的结果相比,平均偏差仅为3.16%,得到的最佳衰退间隔也可以较好吻合.使用SB_CLPE的Cache体系结构可以用于在程序执行过程中对最佳衰退间隔进行实时估算,通过动态调整衰退间隔以达到最优的功耗降低效果.

A Method of Statistics-Based Cache Leakage Power Estimation

Leakage power has become one of the main restrictions on microprocessor design with the decrease of the transistor's dimension,supply voltage and threshold voltage.Two important techniques to reduce leakage power in caches are sleep cache and drowsy cache in which the cache lines unused recently can be put into low-power mode.A cache leakage power estimation method based on statistics(SB-CLPE)is provided in this paper for sleep cache or drowsy cache and a cache architecture using SB-CLPE is designed which can estimate cache leakage power in real time during the execution of programs.According to the statistics of access intervals for all cache lines,the SB-CLPE can estimate the cache leakage power with different decay interval and get the optimum decay interval which can make the leakage power lowest.For sleep cache,the average variation between the leakage power estimated by SB-CLPE and the leakage power from the HotLeakage power simulator is only 3.16%.The optimum decay intervals estimated by SB-CLPE are almost identical with the real optimum decay intervals from HotLeakage.The cache architecture using SB-CLPE can be used for estimating the optimum decay interval in sleep cache or drowsy cache.By adjusting the decay interval dynamically when programs executes,the best power saving result can be achieved.