2 BACKGROUND
2.1 Power-Aware DRAM Interfaces
Figure 1. Basic DRAM Interface, with four independent channels (C), one quad ranked DIMM per channel (R), and eight internal banks (B) per rank.
A basic DRAM interface has one or more DRAM channels; each channel consists of one or more memory modules.Most modern DRAM systems make use of dual in-line memory modules (DIMM); each DIMM consists of one or more ranks-a set of DRAM devices that operate in lockstep. Each DRAM device contains a set of independent memory arrays called banks. A bank is made up of rows (a.k.a. DRAM pages), which are simply a set of storage cells that are acted upon in parallel. Figure 1 shows a DRAM system interface, with four independent DRAM channels (C). Each channel has one quad ranked DIMM (R), with eight internal banks (B) per rank.