MT16JSF25664H Micron Semiconductor Products, MT16JSF25664H Datasheet - Page 7

• Manufacturer Part Number: MT16JSF25664H
• Description: Ddr3 Sdram Sodimm
• Manufacturer: Micron Semiconductor Products

General Description
Fly-By Topology
Temperature Sensor with Serial Presence-Detect EEPROM
Thermal Sensor Operations
Serial Presence-Detect EEPROM Operation
PDF: 09005aef83364b70/Source: 09005aef83364bd3
JSF16C256x64HZ.fm - Rev. A 5/08 EN
The MT16JSF25664H DDR3 SDRAM module is a high-speed, CMOS dynamic random
access 2GB memory module organized in a x64 configuration. This DDR3 SDRAM
module uses internally configured, 8-bank 1Gb DDR3 SDRAM devices.
DDR3 SDRAM modules use double data rate architecture to achieve high-speed opera-
tion. The double data rate architecture is essentially an 8n-prefetch architecture with an
interface designed to transfer two data words per clock cycle at the I/O pins. A single
read or write access for the DDR3 SDRAM module effectively consists of a single
8n-bit-wide, one-clock-cycle data transfer at the internal DRAM core and eight corre-
sponding n-bit-wide, one-half-clock-cycle data transfers at the I/O pins.
The differential data strobe (DQS, DQS#) is transmitted externally, along with data, for
use in data capture at the DDR3 SDRAM input receiver. DQS is center-aligned with data
for WRITEs. The read data is transmitted by the DDR3 SDRAM and edge-aligned to the
data strobes.
DDR3 SDRAM modules operate from a differential clock (CK and CK#); the crossing of
CK going HIGH and CK# going LOW will be referred to as the positive edge of CK.
Control, command, and address signals are registered at every positive edge of CK. Input
data is registered on both edges of DQS, and output data is referenced to both edges of
DQS, as well as to both edges of CK.
These DDR3 modules use faster clock speeds than earlier DDR technologies, making
signal quality more important than ever. For improved signal quality, the clock, control,
command, and address buses have been routed in a fly-by topology, where each clock,
control, command, and address pin on each DRAM is connected to a single trace and
terminated (rather than a tree structure, where the termination is off the module near
the connector). Inherent to fly-by topology, the timing skew between the clock and DQS
signals can be easily accounted for by using the write leveling feature of DDR3.
The temperature from the integrated thermal sensor is monitored and converts into a
digital word via the I
to create a custom temperature-sensing solution based on system requirements.
Programming and configuration details comply with JEDEC Standard No. 21-C, page
4.7-1, “Mobile Platform Memory Module Thermal Sensor Component Specification.”
DDR3 SDRAM modules incorporate serial presence-detect. The SPD data is stored in a
256-byte EEPROM. The first 128 bytes are programmed by Micron to comply with JEDEC
Standard JC-45 “Appendix X: Serial Presence Detect (SPD) for DDR3 SDRAM Modules”
(pending approval). These bytes identify module-specific timing parameters, configura-
tion information, and physical attributes. User-specific information can be written into
the remaining 128 bytes of storage. READ/WRITE operations between the system
(master) and the EEPROM (slave) device occur via an I2C bus. Write protect (WP) is
connected to Vss, permanently disabling hardware write protect.
2GB (x64, DR) 204-Pin Halogen-Free DDR3 SDRAM SODIMM
2
C bus. System designers can use the user-programmable registers
7
Micron Technology, Inc., reserves the right to change products or specifications without notice.
General Description
©2008 Micron Technology, Inc. All rights reserved