DATA SHEET
512MB Registered DDR SDRAM DIMM
EBD51RC4AKFA-E (64M words × 72 bits, 1 Rank)
Description
Features
The EBD51RC4AKFA is a 64M words × 72 bits, 1 rank
Double Data Rate (DDR) SDRAM Module, mounting 18
pieces of DDR SDRAM sealed in TSOP 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
• 184-pin socket type dual in line memory module
(DIMM)
PCB height: 30.48mm
Lead pitch: 1.27mm
Lead-free
• 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
utilizing surface mount technology.
Decoupling
• Bi-directional, data strobe (DQS) is transmitted
/received with data, to be used in capturing data at
the receiver
capacitors are mounted beside each TSOP on the
module board.
• Data inputs and outputs are synchronized with DQS
• 4 internal banks for concurrent operation
(Components)
• 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, 2 pieces of register
drivers and 1 piece of serial EEPROM (2k bits
EEPROM) for Presence Detect (PD)
Document No. E0608E10 (Ver. 1.0)
Date Published October 2004 (K) Japan
URL: http://www.elpida.com
Elpida Memory,Inc. 2004