DRAM operating states and burn in

Observation of system level DRAM operations can provide insights for developing improved reliability screens such as burn-in. We instrumented a dual rank 4GB RDIMM to probe command bus traffic from the memory controller to the DRAMs on a server mother board. Internal DRAM operating states are derived by analyzing the command bus traffic. Analysis showed that when the controller uses an open page policy with bank interleaving, the active idle state can become the dominant bias configuration in activated arrays. This result can be applied to the development of an efficient burn in stress.