Energy efficient address assignment through minimized memory row switching

Data transfer intensive applications consume a significant amount of energy in memory access. The selection of a memory location from a memory array involves driving row and column select lines. A signal transition on a row select line often consumes significantly more energy than a transition on a column select line. In order to exploit this difference in energy consumption of row and column select lines, we propose a novel address assignment methodology that aims to minimize high energy row transitions by assigning spatially and temporally local data items to the same row. The problem of energy efficient address assignment has been formulated as a multi-way graph partitioning problem and solved with a heuristic. Our experiments demonstrate that our methodology achieves row transition counts very close to the optimum and that the methodology can, for some examples, reduce row transition count by 40--70% over row major mapping. Moreover, we also demonstrate that our methodology is capable of handling access sequences with over 15 million accesses in moderate time.