[Nanya]

Description

The 256Mb DDR SDRAM is a high-speed CMOS, dynamic random-access memory containing 268,435,456 bits. It is internally configured as a quad-bank DRAM.

Features

• Double data rate architecture: two data transfers per clock cycle

• Bidirectional data strobe (DQS) is transmitted and received with data, to be used in capturing data at the receiver

• DQS is edge-aligned with data for reads and is centeraligned with data for writes

• Differential clock inputs (CK and CK)

• Four internal banks for concurrent operation

• Data mask (DM) for write data

• 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

• Burst lengths: 2, 4, or 8

• CAS Latency: 2, 2.5

• Auto Precharge option for each burst access

• Auto Refresh and Self Refresh Modes

• 7.8ms Maximum Average Periodic Refresh Interval

• 2.5V (SSTL_2 compatible) I/O

• VDDQ = 2.5V ± 0.2V

• VDD = 2.5V ± 0.2V

• Package : 66pin TSOP-II / 60 balls 0.8mmx1.0mm pitch CSP.