A High-Performance and Low-Power Cache Architecture with Speculative Way-Selection

Koji INOUE  Tohru ISHIHARA  Kazuaki MURAKAMI  

Publication
IEICE TRANSACTIONS on Electronics   Vol.E83-C   No.2   pp.186-194
Publication Date: 2000/02/25
Online ISSN: 
DOI: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Low-Power High-Speed CMOS LSI Technologies)
Category: 
Keyword: 
cache,  low power,  low energy,  way prediction,  high performance,  

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Summary: 
This paper proposes a new approach to achieving high performance and low energy consumption for set-associative caches. The cache, called way-predicting set-associative cache, speculatively selects a single way, which is likely to contain the data desired by the processor, from the set designated by a memory address, before it starts a normal cache access. By accessing only the single way predicted, instead of accessing all the ways in a set, energy consumption can be reduced. In order for the way-predicting cache to perform well, accuracy of way prediction is important. This paper shows that the accuracy of an MRU (most recently used)-based way prediction is higher than 90% for most of the benchmark programs. The proposed way-predicting cache improves the ED (energy-delay) product by 60-70% compared to the conventional set-associative cache.