NAND flash memory host interface spec ratified
A specification for a host computer intrface to non-volatile memory has been produced by a working group set up by Dell, Intel and Microsoft (DIM).
The not very charismatically named Non-Volatile Memory Host Controller Interface (NCMHCI) working group was set up about a year ago, chaired by Intel which was then not keen to get out of the flash memory business at all. How times change? Virtually the same day that Intel CEO Paul Otellini is talking about, nod, wink, Intel examining all options for its flash business, the working group issues a ratified v1.0 specification.
The spec is an API for use by operating system drivers and intended, Intel states, to help ‘hardware component designers, system builders and software/driver developers take advantage of the operating system and non-volatile memory capabilities for improved system performance, lower power consumption, quieter operation, smaller form factors and increased ruggedness.’
It describes the interface to the HW registers involved and a description of the HW/SW interface between operating system SW and the NAND controller hardware, plus the command set used with flash devices. The flash memory could be either a solid state disk or a hard disk drive cache.
The interface to the non-volatile memory consists of eight commands in total. It includes features like dataset management that allows the O/S to provide information to the NVMHCI controller on how to best optimise data for performance and endurance. NVMHCI is designed to work with the standard Serial ATA programming interface (AHCI), which enables seamless caching of the hard drive contents into non-volatile memory by a single software driver.
Organisations that want to use the spec need to sign a royalty-free license with Intel. The company will add additional contributor inputs and will issue v1.n revisions as time and circumstances permit.
There are about 35 members of the working group and one of them might have to take on the chairing role if Intel does exit the flash business altogether.