DRAM

DRAM Refresh Restores Charge Before Bits Fade

Dynamic random-access memory stores data in cells whose electrical state does not remain stable indefinitely. Charge leaks from a cell over time, even when software performs no reads or writes. A memory system therefore has to refresh DRAM periodically to preserve stored bits. Refresh is a maintenance operation rather than a request from an application. The memory controller and DRAM device coordinate it alongside ordinary reads and writes. During parts of that work, some memory resources cannot serve normal requests.