An effective SDRAM power mode management scheme for performance and energy sensitive embedded systems

We present an effective power mode management scheme used in SDRAM memory controllers. The scheme employs a bus utilization monitoring mechanism to initiate proper operations of SDRAM chips. Our approach reduces energy consumption by actively switching memories to low-power mode at low bus utilization. At higher bus utilization, the scheme switches memories to open page mode to reduce precharge energy as well as program execution time. This bus utilization predictor reduces memory energy consumption without the expense of increasing program execution time. It achieved the performance level of open page policy by consuming 20% less of memory energy.