Abstract:

Recent researches show that traditional hardware-only cache replacement strategies seriously hamper the
improvement of cache performance. This paper proposes a novel scheme of software-controllable cache for embedded
systems. In this scheme, a software-controller module is added to the traditional architecture to implement the
following three operations controlled by software: For data that incur heavy access cost and have a wide activity
space, a copy is retained in the cache. Data that cause a drop in the cache pre-fetching temporal locality are directly
exchanged between the processor and the external memory. Data with less access cost and a narrow activity space
preferentially remain in the cache during activities. Simulation results show that the proposed approach can improve
the system performance by 11% and reduce bus occupancy by 28%.

Key words: cache, replacement strategies, embedded systems, software-controllable