HYB25D256800BT

HYB25D256[800/160]BT(L)-[5/5A] 256MBit Double Data Rata SDRAM Preliminary DDR400 Data Sheet Addendum Jan. 2003, V0.9 Features CAS Latency and Clock Frequency CAS Latency 2 2.5 3 Maximum Operating Frequency (MHz) DDR400B DDR400A -5 -5A 133 133 166 200 200 200 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 center-aligned 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: (1.5), 2, 2.5, (3) Auto Precharge option for each burst access Auto Refresh and Self Refresh Modes 7.8ms Maximum Average Periodic Refresh Interval (8k refresh) 2.5V (SSTL_2 compatible) I/O VDDQ = 2.6V ± 0.1V / VDD = 2.6V ± 0.1V TSOP66 package 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. The 256Mb DDR SDRAM uses a double-data-rate architecture to achieve high-speed operation. The double data rate architecture is essentially a 2n prefetch architecture with an interface designed to transfer two data words per clock cycle ...