ABSTRACT

Processors need memory that provides fast random access for both read and write operations (random access memory [RAM]). The two most common memory technologies for this purpose are static RAM (SRAM), which uses a flip-flop to store data, and dynamic RAM (DRAM), which uses a capacitor. Both are volatile memory; that is, the memory contents are only preserved as long as the memory device is powered (as opposed to nonvolatile memory like flash or electrically erasable programmable read-only memory [EEPROM]). Compared to SRAM, DRAM has the advantage of small cells (6 to 8 F2, as opposed to >100 F2 for SRAM [1]). On the other hand, the dynamic nature of DRAM requires periodic refresh operations.