描述 Description

The EDD5104AB is a 512M bits Double Data Rate (DDR) SDRAM organized as 33,554,432 words × 4 bits × 4 banks. The EDD5108AB is a 512M bits DDR SDRAM organized as 16,777,216 words × 8 bits × 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 resistor, the on-chip Delay Locked Loop (DLL) can be set enable or disable. They are packaged in standard 66-pin plastic TSOP (II)10.16mm(400).

特性 Features

? 2.5 V power supply: VDDQ = 2.5V ± 0.2V : VDD = 2.5V ± 0.2V

? Data Rate: 333Mbps/266Mbps (max.)

? Double Data Rate architecture; two data transfers per clock cycle

? Bi-directional, data strobe (DQS) is transmitted/received with data, to be used in capturing data at the receiver

? Data inputs, outputs, and DM are synchronized with DQS

? 4 internal banks for concurrent operation

? DQS is edge aligned with data for READs; center aligned with data for WRITEs

? Differential clock inputs (CK and /CK)

? DLL aligns DQ and DQS transitions with CK transitions

? Commands entered on each positive CK edge; data and data mask referenced to both edges of DQS

? Data mask (DM) for write data

? Auto precharge option for each burst access

? 2.5 V (SSTL_2 compatible) I/O

? Programmable burst length (BL): 2, 4, 8

? Programmable /CAS latency (CL): 2, 2.5

? Refresh cycles: 8192 refresh cycles/64ms

- 7.8μs maximum average periodic refresh interval

? 2 variations of refresh

- Auto refresh

- Self refresh