Internet Data Sheet
HY[B/I]18T256[40/80/16]0A[C/F](L)
256-Mbit Double-Data-Rate-Two SDRAM
1
Overview
This chapter gives an overview of the 256-Mbit Double-Data-Rate-Two SDRAM product family and describes its main
characteristics.
1.1
Features
The 256-Mbit Double-Data-Rate-Two SDRAM offers the following key features:
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1.8 V ± 0.1 V Power Supply
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Off-Chip-Driver impedance adjustment (OCD) and
On-Die-Termination (ODT) for better signal quality
Auto-Precharge operation for read and write bursts
Auto-Refresh, Self-Refresh and power saving Power-
Down modes
1.8 V ± 0.1 V (SSTL_18) compatible I/O
DRAM organizations with 4,8,16 data in/outputs
Double Data Rate architecture:
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– two data transfers per clock cycle
– four internal banks for concurrent operation
Programmable CAS Latency: 3, 4, 5 and 6
Programmable Burst Length: 4 and 8
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Average Refresh Period 7.8 μs at a TCASE lower
than 85 °C, 3.9 μs between 85 °C and 95 °C
Programmable self refresh rate via EMRS2 setting
Programmable partial array refresh via EMRS2 settings
DCC enabling via EMRS2 setting
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Differential clock inputs (CK and CK)
Bi-directional, differential data strobes (DQS and DQS) are
transmitted / received with data. Edge aligned with read
data and center-aligned with write data.
DLL aligns DQ and DQS transitions with clock
DQS can be disabled for single-ended data strobe
operation
Commands entered on each positive clock edge, data and
data mask are referenced to both edges of DQS
Data masks (DM) for write data
Full and reduced Strength Data-Output Drivers
1KB page size
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Packages: PG-TFBGA-84, PG-TFBGA-60, P-TFBGA-84,
P-TFBGA-60
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RoHS Compliant Products1)
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All Speed grades faster than DDR2–400 comply with
DDR2–400 timing specifications when run at a clock rate
of 200 MHz.
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Posted CAS by programmable additive latency for better
command and data bus efficiency
1) RoHS Compliant Product: Restriction of the use of certain hazardous substances (RoHS) in electrical and electronic equipment as defined
in the directive 2002/95/EC issued by the European Parliament and of the Council of 27 January 2003. These substances include mercury,
lead, cadmium, hexavalent chromium, polybrominated biphenyls and polybrominated biphenyl ethers.
Rev. 1.50, 2007-12
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03062006-7M17-PXBC