JEDEC's JC-45 Committee has approved the first standards for support of "hybrid" DDR4 memory modules which are defined as modules that plug into standard dual in-line memory module (DIMM) sockets and appear like a DDR4 SDRAM to the system controller, yet contain non-volatile (NV) memories such as NAND Flash on the module.
These hybrid module families are referred to as Non-Volatile DIMMs, or NVDIMMs, and they may share the memory channel with other standard DDR4 DIMMs.
JEDEC?s JC-45 Committee for Memory Modules developed the NVDIMM taxonomy in cooperation with the NVDIMM Special Interest Group (SIG), a subcommittee of the Solid State Storage Initiative within the Storage Networking Industry Association (SNIA). The first two versions of these hybrid modules are the NVDIMM-N, which combines DRAM and NAND Flash where the Flash provides backup and restore of all DRAM for reliable data persistence through power failure; and the NVDIMM-F, which provides directly addressable NAND Flash which is accessed as a block oriented mass storage device.
Hybrid modules such as the NVDIMM-N and NVDIMM-F are supported in new DDR4 Serial Presence Detect (SPD) codes to be released later this year, and new standard DDR4 DIMM labels are in the review process for release in 2015 as well. JEDEC has also defined specific signals on the DIMM connector to facilitate plug-and-play implementation of NVDIMMs on standard platforms.