GENERAL DESCRIPTION

The 64Mb (x32) DDR SDRAM is a high-speed CMOS, dynamic random-access memory containing 67,108,864 bits. It is internally configured as a quad-bank DRAM.

FEATURES

• Bidirectional data strobe (DQS) transmitted/ received with data, i.e., source-synchronous data capture

• Internal, pipelined double-data-rate (DDR) architecture; two data accesses per clock cycle

• Reduced output drive option

• Differential clock inputs (CK and CK#)

• Commands entered on each positive CK edge

• DQS edge-aligned with data for READs; centeraligned with data for WRITEs

• DLL to align DQ and DQS transitions with CK

• Four internal banks for concurrent operation

• Data mask (DM) for masking write data

• Programmable burst lengths: 2, 4, 8, or full page

• 32ms, 4,096-cycle auto refresh (7.8µs/cycle)

• Auto precharge option

• Auto Refresh and Self Refresh Modes

• Programmable I/O (SSTL_2 compatible) – reduced and impedance matched