EBE25UD6ABFA Datasheet, PDF (1/22 Pages) Elpida Memory – 256MB Unbuffered DDR2 SDRAM DIMM

PRELIMINARY DATA SHEET
256MB Unbuffered DDR2 SDRAM DIMM
EBE25UD6ABFA (32M words × 64 bits, 1 Rank)
Description
The EBE25UD6ABFA is 32M words × 64 bits, 1 rank
DDR2 SDRAM unbuffered module, mounting 4 pieces
of 512M bits DDR2 SDRAM sealed in FBGA package.
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 4 bits prefetch-pipelined
architecture. Data strobe (DQS and /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. This module provides high density
mounting without utilizing surface mount technology.
Decoupling capacitors are mounted beside each FBGA
on the module board.
Note: Do not push the components or drop the
modules in order to avoid mechanical defects,
which may result in electrical defects.
Features
• 240-pin socket type dual in line memory module
(DIMM)
 PCB height: 30.0mm
 Lead pitch: 1.0mm
 Lead-free
• 1.8V power supply
• Data rate: 533Mbps/400Mbps (max.)
• 1.8V (SSTL_18 compatible) I/O
• Double-data-rate architecture: two data transfers per
clock cycle
• Bi-directional, differential data strobe (DQS and
/DQS) is transmitted/received with data, to be used in
capturing data at the receiver
• 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
• Four internal banks for concurrent operation
(components)
• Data mask (DM) for write data
• Burst lengths: 4, 8
• /CAS Latency (CL): 3, 4, 5
• Auto precharge operation for each burst access
• Auto refresh and self refresh modes
• 7.8µs average periodic refresh interval
• Posted CAS by programmable additive latency for
better command and data bus efficiency
• Off-Chip-Driver Impedance Adjustment and On-Die-
Termination for better signal quality
• /DQS can be disabled for single-ended Data Strobe
operation
Document No. E0534E11 (Ver. 1.1)
Date Published February 2006 (K) Japan
URL: http://www.elpida.com
Elpida Memory, Inc. 2004-2006