A single cycle accessible two-level cache architecture for reducing the energy consumption of embedded systems

Employing a small L0-cache between an MPU core and an L1-cache is one of the most promising approaches for reducing the energy consumption of memory subsystems. Since the L0-cache is small, if there is a hit, the energy consumption will be reduced. On the other hand, if there is a miss, one extra cycle is required to access the L1-cache. This leads to a degradation of the processor performance. For resolving this problem, a single cycle accessible two-level cache (STC) architecture is proposed in this paper. This architecture makes it possible to access to both the L0 and the L1 caches from an MPU core in a cycle. Experiments using several benchmark programs demonstrate that the STC architecture reduces the energy consumption of memory subsystems by 13% without any performance degradation compared to the best results obtained by previous approaches.