The EDD2508AK is a 256M bits DDR SDRAM organized as 8,388,608 words x 8 bits x 4 banks. Read and write operations are performed at the cross points of the CK and the /CK. This high-speed data transfer is realized by the 2 bits prefetch-pipelined architecture. Data strobe (DQS) both for read and write are available for high speed and reliable data bus design. By setting extended mode register, the on-chip Delay Locked Loop (DLL) can be set enable or disable. It is packaged in standard 66-pin plastic TSOP (II).