®
IDT
® ADVANCED MEMORY BUFFER (AMB)
®
IDT® ADVANCED MEMORY BUFFER (AMB)
Improve FB-DIMM Performance
with IDT Advanced Memory Buffers
Advanced Memory Buffers, the next generation of FDIMM controllers, allow more DIMMS in a single
system, ideal for servers, workstations, storage devices and communication applications. The unique
channel structure of the IDT AMB chip alleviates buffer loading issues. The IDT AMB+ family offers
unparalleled power saving over standard AMB, which translates into a dramatic improvement in overall
cost and energy effi ciency.
The essential building block for next-generation,
high-bandwidth applications
The fully buffered dual in-line memory module (FB-DIMM) is the next generation memory architecture
to meet the growing memory requirement of servers and workstations. The IDT advanced memory buffer
(AMB) chip is the essential building block located on each FB-DIMM. The IDT AMB receives commands
and data from the host controller to control and write/read data to/from the DRAMs on the DIMM. Commands
and write data are sent southbound from the host controller to AMBs in a daisy chain fashion and interpreted
by the target AMB. Status and read data are sent northbound from AMBs to the host controller also in a daisy
chain fashion, passing through non-target AMBs. This unique channel structure alleviates buffer loading
issues common in registered DIMM technology, enabling designers to use a large number of DIMMs
within a single system. The IDT AMB complies with the latest JEDEC specifi cation for AMB and supports
DDR2-533/667/800 DRAM. It also enables serial data transfer at 3.2, 4.0 and 4.8 Gbps. The IDT AMB supports
servers, workstations, storage devices and communication applications that support the next generation
FB-DIMM architecture.
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IDT® ADVANCED MEMORY BUFFER (AMB)
®
® 2008 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. IDT and the IDT logo are registered trademarks of Integrated Device
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Printed in USA 3-08/DG/BWD/HOP/2k FLYR-AMB-038
For complete parametric information, technical documentation, AMB-related white papers and press releases,
as well as comprehensive information on the wide variety of related parts that IDT offers, please visit
www.IDT.com/go/amb
You can also receive IDT product-related newsletters and updates and find local distributors by registering
at myIDT.com. Select the myIDT menu on the upper right tab of the www.IDT.com web page, and select
“Register for myIDT” or go directly to www.IDT.com/go/register.
The IDT AMB+ family of ultra-low power AMB devices offers unparalleled power savings over standard
AMB offerings. This family of devices leverages the industry-proven AMB design and systems expertise
that has made IDT the market leader for memory interface solutions. With regulated (JEDEC plug and play)
and unregulated versions, an unparalleled feature set, frequencies up to 800MHz and standard and low
voltage DRAM support, the AMB+ sets a new standard for next generation FB-DIMM designs. By leveraging
the capabilities of low voltage core and DRAM supplies, power savings greater than 50% are achievable
versus today’s standard power AMB devices. This translates into a dramatic improvement in overall cost and
energy efficiency, both from power and cooling, when AMB+ based memory subsystems are used in
today’s new crop of advanced servers and workstations.
Features Benefits
Leverages high-speed serial technology for DRAM interface • Serial technology provides increased scalability for future growth; therefore, meeting
the needs of increasing server processing power
• Minimizes memory interface pin-count to ease board design issues
• PC boards have fewer layers and simpler trace routing which reduce manufacturing
and design costs.
Supports 3.2, 4.0 and 4.8 Gbits serial speeds (DDR2-533/667/800) • High-speed memory support for increased performance
• Multiple speed FB-DIMMs can be built using the same product
Support for 14 northbound lanes (read) and 10 southbound lanes (write) • Optimized architecture for real-world usage patterns
Support for up to 8 DIMMs per channel • Higher flexibility in memory size selection allowing user to utilize cost-effective
DRAM sizes
• Increased expandability beyond traditional DIMMs, for example, systems with 4 channels
can support up to 128 GB of memory using 4 GB DIMMs
Can be used as a repeater for extending FB-DIMM links • Allows greater flexibility of memory subsystem placement within a system
Supports failover and channel detection error modes • Increased data channel redundancy that minimizes system down time and increases
system reliability
Built to industry standard JEDEC support • Allows compatibility for end-user plug & play
SMBus protocol interface with PEC support • Allows alternate access mechanism to the AMB configuration and status registers
Testing features supported include: • Built in self-test modes allow enhanced test coverage without the need for expensive
– Integrated thermal sensor and status indicator test equipment
– Supports MEMBIST, IBIST and virtual host mode design-for-test functions • Eases debugging tasks
– Transparent mode and direct access mode for DRAM testing
AMB protocol supports high-speed lane-to-lane de-skewing • Reduces the need for time consuming bit-length matching of PC board traces
Reduce your FB-DIMM Power with IDT AMB+
Type of AMB technology Ultra low power FB-DIMM enabled by IDT AMB+
Power consumption
Current Industry AMB (1.5Vcc / 1.8Vdd)
Current Industry AMB (1.5Vcc / 1.5Vdd)
AMB+ Regulated (1.5Vcc / 1.8Vdd)
AMB+ Regulated (1.5Vcc / 1.5Vdd)
AMB+ Unregulated (1.1Vcc / 1.8Vdd)
AMB+ Unregulated (1.1Vcc /1.5Vdd)
0%
40%
50%
60%
70%
80%
90%
100%
100%
45%
54%
65%
73%
94.29%
