Optimizated allocation of data variables to pcm/dram-based hybrid main memory for real-time embedded systems

Phase-change memory (PCM) has many advantages compared to conventional DRAM, including nonvolatility, low static energy consumption, and high reliability. Its drawbacks include limited write-endurance and higher energy consumption for write operations. We consider a hybrid main memory consisting of PCM and DRAM at the same level of the memory hierarchy, and address the problem of partitioning and allocating data variables in a multitasking system to either memory type to minimize the energy consumption in the hyper-period while respecting the user-specified upper bounds on CPU utilization. We present an optimal integer linear programming (ILP) formulation and a heuristic algorithm with polynomial time complexity.