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