ONFi Adds Block Abstraction to NAND Flash

The Open NAND flash Interface (ONFi) Working Group, the organization dedicated to simplifying integration of NAND flash memory into consumer electronic (CE) devices, computing platforms and industrial systems, today announced the Block Abstracted addendum specification. This new specification will help simplify the design of host controllers.

Most of the NAND flash memory products in the market today feature physical-address access that defines each physical memory array to the block and to the page–down to the byte of data. The driver in the host controller must recognize this complicated addressing. Any change in device architecture requires modifications to the driver in the host controller, making system upgrades extremely difficult and expensive. Block Abstracted (BA) simplifies host controller design by allowing the host to treat the flash as a pool of addressable blocks of data, without having to manage those blocks individually.

“Industry-standard Block Abstracted NAND flash components offered by multiple sources can significantly reduce time-to-market for new products, while lowering cost of development,” said Bob Leibowitz, ONFi Marketing Chair and NAND Architecture Strategist at Micron. “Our standardization efforts will benefit OEMs while creating new business opportunities for suppliers.”

New flash components based on ONFi’s BA NAND flash specification can incorporate traditional NAND-specific functions such as error-correcting code (ECC), wear-leveling, and bad block management in the internal memory controller, freeing the host of these tasks. Designing systems with BA NAND flash requires no redesign of the host controller when upgrading to different memory densities or changing component suppliers.

BA NAND leverages the existing raw NAND footprint, creating an easy migration path for OEMs using raw NAND today. BA NAND follows ONFi’s method of self-discovery to allow the same host controller to have the flexibility to use both raw and BA NAND.