EBD25RB4ALFA Datasheet, PDF (1/17 Pages) Elpida Memory – 256MB Registered DDR SDRAM DIMM

PRELIMINARY DATA SHEET
256MB Registered DDR SDRAM DIMM
EBD25RB4ALFA (32M words × 72 bits, 1 Bank)
Description
The EBD25RB4ALFA is a 32M × 72 × 1 bank Double
Data Rate (DDR) SDRAM Module, mounted 18 pieces
of 128M bits DDR SDRAM (EDD1204ALTA) sealed in
TSOP package, 1 piece of PLL clock driver, 2 pieces of
register driver and 1 piece of serial EEPROM (2k bits
EEPROM) for Presence Detect (PD). Read and write
operations are performed at the cross points of the
CLK and the /CLK. 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. An outline of
the products is 184-pin socket type package (dual lead
out). Therefore, it makes high density mounting
possible without surface mount technology. It provides
common data inputs and outputs. Decoupling
capacitors are mounted beside each TSOP on the
module board.
Features
• 184-pin socket type dual in line memory module
(DIMM)
 Outline: 133.35mm (Length) × 43.18mm (Height) ×
4.00mm (Thickness)
 Lead pitch: 1.27mm
• 2.5V power supply (VDD/VDDQ)
• SSTL-2 interface for all inputs and outputs
• Clock frequency: 133MHz/100MHz (max.)
• Data inputs and outputs are synchronized with DQS
• 4 banks can operate simultaneously and
independently (Component)
• Burst read/write operation
• Programmable burst length: 2, 4, 8
 Burst read stop capability
• Programmable burst sequence
 Sequential
 Interleave
• Start addressing capability
 Even and Odd
• Programmable /CAS latency (CL): 2, 2.5
• 4096 refresh cycles: 15.6µs (4096/64ms)
• 2 variations of refresh
 Auto refresh
 Self refresh
Document No. E0211E11 (Ver. 1.1)
Date Published October 2001 (K)
Printed in Japan
URL: http://www.elpida.com
C Elpida Memory, Inc. 2001
Elpida Memory, Inc. is a joint venture DRAM company of NEC Corporation and Hitachi, Ltd.