Mobile XDR™ Innovations

The Rambus Mobile XDR™ architecture incorporates innovations first developed as part of the Mobile Memory Initiative. The innovations that enable the high bandwidth and low power of the Mobile XDR memory architecture include:

• Very Low-Swing Differential Signaling (VLSD) combines the robust signaling qualities of a differential architecture with innovative circuit techniques to greatly reduce active power consumption. Using a ground reference voltage mode driver, VLSD enables data rates of up to 4.3Gbps with only a 200mV peak-to-peak differential voltage swing and a common mode of 100mV.


• FlexClocking™ Architecture is a topology where the clock is forwarded and distributed to both the controller and the DRAM device from a central PLL. Using Rambus FlexPhase™ technology to adjust for any variability between the clock and DQ signals, the FlexClocking Architecture enables high-speed operation without the need for a DLL or PLL on the DRAM device. This simplifies DRAM design and reduces power consumption.


• Advanced Power State Management (APSM) builds on the FlexClocking architecture and innovative circuit design techniques. APSM reduces memory system power, optimizes power efficiency across operating modes, and provides ultra-fast transition times between various low-power and active operating modes.

In addition to VLSD, FlexClocking architecture, and APSM, the Mobile XDR architecture features the following Rambus innovations:

• Micro-Threading Technology - reduces row and column access granularity resulting in a significant performance benefit for applications dealing with small data objects.


• FlexLink™ C/A - provides the command and address information to a DRAM using a single, differential high speed communications channel.


• Fully Differential Memory Architecture (FDMA) - enables higher speed, lower noise and lower power in high performance memory systems.


• Dynamic Point-to-Point (DPP) - enables memory upgrades and expandable capacity while maintaining high-performance point-to-point signaling.