Provided by:
Georgia Institute of Technology
Topic:
Storage
Format:
PDF
DRAMs require periodic refresh for preserving data stored in them. The refresh interval for DRAMs depends on the vendor and the design technology they use. For each refresh in a DRAM row, the stored information in each cell is read out and then written back to itself as each DRAM bit read is self-destructive. The refresh process is inevitable for maintaining data correctness, unfortunately, at the expense of power and bandwidth overhead. The future trend to integrate layers of 3D die-stacked DRAMs on top of a processor further exacerbates the situation as accesses to these DRAMs will be more frequent and hiding refresh cycles in the available slack becomes increasingly difficult.