EDE2508ABSE Datasheet, PDF (1/66 Pages) Elpida Memory – 256M bits DDR2 SDRAM

PRELIMINARY DATA SHEET
256M bits DDR2 SDRAM
EDE2508ABSE (32M words × 8 bits)
EDE2516ABSE (16M words × 16 bits)
Description
The EDE2508ABSE is a 256M bits DDR2 SDRAM
organized as 8,388,608 words × 8 bits × 4 banks.
It is packaged in 60-ball FBGA (µBGA^) package.
The EDE2516ABSE is a 256M bits DDR2 SDRAM
organized as 4,194,304 words × 16 bits × 4 banks.
It is packaged in 84-ball FBGA (µBGA) package.
Features
• Power supply: VDD, VDDQ = 1.8V ± 0.1V
• 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
• Data mask (DM) for write data
• Burst lengths: 4, 8
• /CAS Latency (CL): 4, 5
• Auto precharge operation for each burst access
• Auto refresh and self refresh modes
• Average refresh period
 7.8µs at 0°C ≤ TC ≤ +85°C
 3.9µs at +85°C < TC ≤ +95°C
• SSTL_18 compatible I/O
• 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
• Programmable RDQS, /RDQS output for making × 8
organization compatible to × 4 organization
• /DQS, (/RDQS) can be disabled for single-ended
Data Strobe operation.
• FBGA (µBGA) package with lead free solder
(Sn-Ag-Cu)
Document No. E0573E30 (Ver. 3.0)
Date Published May 2005 (K) Japan
Printed in Japan
URL: http://www.elpida.com
Elpida Memory, Inc. 2004-2005