Embedded DRAM Technologies: Comparisons and Design Tradeoffs

The use of embedded DRAM technology has become widespread, especially in higher-end system designs, because of its superior performance, silicon area savings, and low power compared to discrete memory solutions. Traditionally, in cost-sensitive consumer applications, large memory arrays of 64 megabits and above were usually better suited to discrete commodity memory implementations. But as the supply of low-density DRAM wanes and prices rise, system designers are finding that embedding DRAM densities of 16 Mbits and below is more cost effective per chip than discrete alternatives. A highly integrated embedded DRAM approach also simplifies board design, thereby reducing overall system cost and time to market. Even more importantly, embedding DRAM enables higher bandwidth by allowing a wider on-chip bus, and saves power by eliminating DRAM I/O. Today, designers can take advantage of these capabilities as various 0.25-micron embedded DRAM technologies enter production, with 0.18-micron to follow by the end of year 2000.