Data Matters - A blog about flash memory » managed NAND http://blog.datalight.com Datalight's blog on flash memory, device data storage, data reliability and the embedded industry Wed, 23 Jun 2010 16:59:21 +0000 http://wordpress.org/?v=2.8 en hourly 1 The Datalight Labs: Managed NAND vs. Raw NAND http://blog.datalight.com/the-datalight-labs-managed-nand-vs-raw-nand http://blog.datalight.com/the-datalight-labs-managed-nand-vs-raw-nand#comments Wed, 22 Jul 2009 03:05:41 +0000 RobHart http://blog.datalight.com/?p=121 Our R&D folks couldn’t wait to get their hands on the new test board from Digi which arrived a couple weeks ago. The board comes with multiple testing interfaces, making it easy to switch between a number of different flash parts for back-to-back comparisons. They have been practically wearing the thing out, testing the performance of a number of different managed and raw NAND parts to get a better idea of the differences our customers see when doing benchmarks. Check out a few pictures of the setup currently in Glenn’s office, and contact us for more information on this project.

]]> http://blog.datalight.com/the-datalight-labs-managed-nand-vs-raw-nand/feed 0 The Universe of Managed NAND http://blog.datalight.com/the-universe-of-managed-nand http://blog.datalight.com/the-universe-of-managed-nand#comments Thu, 09 Jul 2009 03:33:00 +0000 MayurKamat http://blog.datalight.com/the-universe-of-managed-nand We have talked about managed NAND in a few blog posts before. Usually a combination of raw NAND flash (SLC or MLC) combined with a hardware controller that performs flash management features like bad block management, ECC and wear leveling is referred to as managed NAND. The term covers a huge spectrum of flash-based storage devices so in this post we will try and highlight some of the more prevalent types of managed NAND

The following is an enumeration of some of the popular managed NAND form factors. Please note that the list covers flash technologies used for resident storage and does not cover removable storage like USB flash, SD, etc.

•    eMMC
•    eSD
•    CompactFlash
•    Solid State Drives
•    BA NAND
•    Adaptable NAND
•    Specialized
–    Specially designed controller + raw flash

CompactFlash is included here because it is used both as resident and removable storage. CF comes with a Fixed-drive option which allows it to be used a resident managed NAND.

The above technologies differ from each other on several attributes

•    Form factor – managed NAND can come is several form factors. An SSD may sport a standard 2.5” drive enclosure whereas a CF card will take a 1.0” card form factor.
•    Plug-in interface: What interface does the managed NAND use to connect to the device platform
–    MMC
–    SD
–    ATA
–    Custom
•    Cost: Cost depends on several elements
–    Type of flash used: SLC is much more expensive than MLC
–    Type of controller used: consumer grade controllers (used for consumer grade CF for example) are much cheaper than specialized industrial grade controllers
•    Performance
–    Performance varies depending on the flash type, the controller attributes and the interface.

Some of the big players in the managed NAND business are

•    eMMC
–    Micron, Numonyx
•    eSD
–    SanDisk, Toshiba
•    BA NAND
–    Toshiba
•    Solid State Drives, CompactFlash
–    Too many players in these markets

This was a brief view of the managed NAND landscape. If there is interest, we will do a follow up going in details about the specific categories and interfaces

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