上传者: mypc51
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上传时间: 2022-03-21 10:45:38
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文件大小: 2.47MB
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文件类型: -
DOUBLE DATA RATE(DDR) SDRAM
VDD = +2.5V ±0.2V, VDDQ = +2.5V ±0.2V
• Bidirectional data strobe (DQS) transmitted/
received with data, i.e., source-synchronous data
capture (x16 has two – one per byte)
• Internal, pipelined double-data-rate (DDR)
architecture; two data accesses per clock cycle
• 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 (x16 has
two – one per byte)
• Programmable burst lengths: 2, 4, or 8
• Auto precharge option
• Auto Refresh and Self Refresh Modes
• Longer lead TSOP for improved reliability (OCPL)
• 2.5V I/O (SSTL_2 compatible)