EBD21RD4ADNA Datasheet, PDF (1/19 Pages) Elpida Memory – 2GB Registered DDR SDRAM DIMM (256M words X72 bits, 2 Ranks)

PRELIMINARY DATA SHEET
2GB Registered DDR SDRAM DIMM
EBD21RD4ADNA (256M words × 72 bits, 2 Ranks)
Description
Features
The EBD21RD4ADNA is a 256M words × 72 bits, 2
ranks Double Data Rate (DDR) SDRAM Module,
mounting 36 pieces of DDR SDRAM sealed in TCP
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 2-bit 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. This module provides high density
mounting without utilizing surface mount technology.
Decoupling capacitors are mounted beside each TCP
on the module board.
Note: Do not push the cover or drop the modules in
order to avoid mechanical defects, which may
result in electrical defects.
• 184-pin socket type dual in line memory module
(DIMM)
 PCB height: 30.48mm
 Lead pitch: 1.27mm
• 2.5V power supply
• Data rate: 333Mbps/266Mbps (max.)
• 2.5 V (SSTL_2 compatible) I/O
• 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 and outputs are synchronized with DQS
• 4 internal banks for concurrent operation
(Component)
• 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
referenced to both edges of DQS
• Auto precharge option for each burst access
• Programmable burst length: 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
• 1 piece of PLL clock driver, 1 piece of register driver
and 1 piece of serial EEPROM (2k bits EEPROM) for
Presence Detect (PD)
Document No. E0433E10 (Ver. 1.0)
Date Published November 2003 (K) Japan
URL: http://www.elpida.com
Elpida Memory,Inc. 2003