The use of NAND flash is growing every year, whether in USB flash drives, Solid State Drives, or music players like Apple's iPod nano.
There are several major components that affect the cost, speed, and reliability of products using flash. These components themselves have variables, including the quality and speed of the NAND flash used, the flash controller, the controller firmware, and the speed and quantity of cache.
The Open NAND Flash Interface (ONFI) workgroup was created in May of 2006 to standardize the low-level interface to NAND flash chips from different manufacturers. This minimizes the changes that need to be made in the firmware of the flash controller, leading to lower costs and a faster time-to-market of newer products. Sometimes, the controller itself is incompatible and cannot be used with a certain flash chip without modifications.
The ONFI workgroup currently has over eighty members that are involved in the NAND flash market either as vendors, customers, or manufacturers. ONFI is also partnering with JEDEC (Joint Electron Device Engineering Council) through a joint task group, which is open to all ONFI and JEDEC members.
Creating a common standard leads to commoditization of a product, lowering costs through price competition from different vendors. Usually, a proprietary format will not survive in the long term because it will cost too much versus the commodity product. However, this does not apply if a company or group of companies is large enough to push its own format, or it offers significant enough performance to be worth the price premium.
Currently, the two largest NAND flash manufacturers are not members of ONFI. Samsung and Toshiba together account for approximately seventy percent of global NAND flash production, although their market share has been dropping by around ten percent annually since ONFI was first standardized. SanDisk is also notably absent from the list of members, as is SSD flash controller manufacturer JMicron, although their major competitor Indilinx has joined ONFI.
Virtually all other NAND flash producers are members of ONFI, such as Hynix, Micron, Intel, Numonyx, and Qimonda. Intel and Micron in particular are making large gains in the NAND flash market, with Micron expected to surpass Toshiba as the number two global producer within the next several years.
In order to counter the threat that ONFI poses, Samsung and Toshiba started cross-licensing their flash intellectual property portfolios. Samsung shared its OneNAND technology, while Toshiba disclosed its LBA-NAND technology, which integrates a controller and NAND flash memory together in a single package. ONFI has developed its own version of LBA-NAND, known as BA-NAND.
Samsung and Toshiba are no strangers to collaboration, having worked together to introduced NAND flash in 1989, nearly twenty years ago. Toshiba still holds several basic NAND flash patents, which it licenses to all NAND manufacturers.
SanDisk, a major flash partner with Toshiba, controls several key Multi-Level Cell technology patents, which it developed over several years in partnership with Toshiba. An MLC flash chip can have two or more bits per cell, versus the single bit of data in Single-Level Cell (SLC) NAND flash chips. Due to the larger capacities and lower costs over SLC, MLC NAND flash has become the dominant type used in SSDs.
Since SanDisk holds these key patents on MLC technology, any company that wishes to be competitive in the NAND flash or SSD markets must pay licensing fees and/or royalties to both SanDisk and Toshiba. This gives them a major competitive edge in the price-sensitive NAND flash market. Both SanDisk and Toshiba have been actively protecting their patent portfolios, as they try to protect their eroding market share from the encroaching ONFI hoard.
quote: Samsung shared its OneNAND technology, while Toshiba disclosed its LBA-NAND technology, which integrates a controller and NAND flash memory together in a single package.