Flex-OneNAND is a complex memory solution that employs both SLC and MLC NAND technologies. According to Samsung, the technology signifies the increasing importance and added value of semiconductors in the design of digital devices.
Thanks to a new semiconductor technology, engineers of GPS phones, MP3 phones, and digital still cameras are able to design with both singlelevel cell (SLC) and multilevel cell (MLC) NAND flash memory technologies using a single-die solution. According to Samsung Electronics Co. Ltd., its Flex-OneNAND fusion semiconductor is not only a first for the industry, it enables much greater flexibility in memory utilization through the easy modification of a CE product even after the original design has been completed.
Tony Kim, senior manager of Flash Technical Marketing at Samsung Semiconductor, Inc., says that the main concept behind the new product is integration. “Current memory architecture for embedded multimedia memory card (eMMC) suggests that users should make use of additional booting memory because current chipsets do not support booting from eMMC,” he explains. “Moreover, depending upon the type of code and data written into the flash memory, some should be written in SLC and some in MLC for optimal efficiency.”
Flex-OneNAND is said to allow designers to freely configure the memory by partitioning the NAND array into SLC and MLC areas. “The software engages a specially designated block for this purpose, which is called the partition information (PI) block,” Kim says. “Designers can add a boundary address, which will differentiate SLC from MLC in this PI Block. Then when power goes on (cold reset) or a special command (PI Update Command) is issued, the area which is lower than the boundary address will become SLC and the area which is higher than the boundary address will become MLC.”
The main benefit of this feature, Kim says, is flexibility. It not only allows designers to configure the semiconductor to their exact design specifications, they can also reconfigure their design just prior to production if market conditions dictate.
The technology is also said to also reduce the area needed for the memory on the printed circuit board and improves performance by diminishing transmission noise. As far as reliability, Kim says the company’s specs indicate that as much as 50K P/E cycles for SLC and 10K P/E cycles for MLC can be guaranteed.
Even with its sophisticated capabilities, Kim says the technology is cost effective. “If we compare the memory architecture of standardized basic eMMC with that of Flex-OneNAND, we realize that eMMC based architecture needs additional SLC-based flash for booting,” he says. “But Flex-OneNAND-based architecture doesn’t need additional memory for booting, which eliminates the additional cost overhead on the overall system.”
The faster read and write capability of SLC NAND flash is said to make it more effective in processing the “code” data used primarily in device boot-up and data downloading, while the greater cost efficiency of MLC NAND makes it more attractive in large-content storage functions. Kim says the semiconductor is mostly likely used in mid- to high-end music or navigational phones, which typically require 4 to 16 GB of flash memory. “It is also an excellent solution for digital still cameras, which require a high density of embedded flash memory for code and storage,” he adds.