Micron NVDIMM General Description
Micron NVDIMM is a new class of nonvolatile memory developed to meet the need for
higher-density, higher-performance memory for enterprise-class storage and server ap-
plications. By combining DRAM, flash, an intelligent system controller, and an ultraca-
pacitor power source, Micron NVDIMM provides a highly reliable memory subsystem
that runs with the latency and endurance of the fastest DRAM, and with the persistence
of flash. Until recently, designers have reluctantly used batteries to maintain their data
during power outages. Others have moved toward new flash-based technologies for
memory persistence, but this option falls short of DRAM in terms of latency, speed, en-
durance, and reliability. Micron NVDIMM enables the fastest possible system perform-
ance while eliminating the many problems associated with batteries, such as hazardous
material disposal, short operating life, and extensive maintenance.
The Micron DDR4 NVDIMM has been specifically designed to operate with host sys-
tems that have implemented the asynchronous DRAM refresh (ADR) feature, although
it is possible to integrate into systems that do not have this enabled. Please contact Mi-
cron for more details on system integration requirements and instructions.
During normal operation, bypass mode, the Micron DDR4 NVDIMM appears as a
standard registered DDR4 DIMM to the host system, providing all the benefits and
speed of a high-speed, high-density SDRAM. In the event of a power loss, the Micron
NVDIMM controller can be commanded to take control of the SDRAM, transferring its
contents to flash memory using energy from its own battery-free power source or from a
system-level persistent power source, thereby preserving all of the SDRAM data. After
power is restored, the Micron NVDIMM controller can be commanded to transfer the
contents from the flash back to the SDRAM and return control to the host system.
Below are a few of the cases that can take advantage of the features of an NVDIMM:
• Nonvolatile write cache for RAID controllers
• Metadata storage
• Whole system persistence
• Unified memory architecture
• Uninterruptable power source (UPS) replacement/complement
DDR4 RDIMM Functionality
DDR4 SDRAM modules are high-speed, CMOS dynamic random access memory mod-
ules that use internally configured 16-bank DDR4 SDRAM devices. DDR4 SDRAM mod-
ules use DDR architecture to achieve high-speed operation. DDR4 is essentially an 8n-
prefetch architecture with an interface designed to transfer two data words per clock cy-
cle at the I/O pins. A single read or write access for the DDR4 SDRAM module effectively
consists of a single 8n-bit-wide, one-clock-cycle data transfer at the internal DRAM core
and eight corresponding n-bit-wide, one-half-clock-cycle data transfers at the I/O pins.
DDR4 modules use two sets of differential signals: DQS/DQS# to capture data and
CK/CK# to capture commands, addresses, and control signals. Differential clocks and
data strobes ensure exceptional noise immunity for these signals and provide precise
crossing points to capture input signals.
8GB (x72, ECC, SR) 288-Pin DDR4 Nonvolatile RDIMM
Micron NVDIMM General Description
PDF: 09005aef85c5dc9c
asf18c1gx72pf1z.pdf - Rev. C 03/16 EN
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