New NAND standard doubles flash memory interface transfer speeds


THE OPEN NAND Flash Interface (ONFI) Working Group has published the ONFI 3.0 standard which doubles the current NAND interface transfer rates to 400MB/sec.

The newly ratified standard uses the non-volatile DDR2 (NV-DDR2) interface. The standard details the interface and infrastructure the working group’s members can use to develop products that deliver the industry’s fastest NAND interface.

According to ONFI, improvements on the NAND interface speeds will enable future NAND controllers to achieve similar performance with half the number of channels, providing cost and space savings for applications like SSDs.

The ONFI 3.0 incorporates a sophisticated die selection feature that reduces the number of chip enable (CE) pins, which in turn lowers the number of controller pins, making PCB routing more efficient.

SSDs will benefit from the lower number of CE pins required, since the extra pins can then be assigned to other applications within the system.

This improved NAND speed means the memory chips can now keep up with the increasing bandwidth offered by interfaces like USB 3.0, SATA, and in the future, Thunderbolt [].

ONFI 3.0 is backwards compatible with previous ONFI standards. In future versions, ONFI 3.0 will also support the ECC Zero (EZ-NAND) interface, which removes burden of the host controller having to keep pace with the fast changing ECC requirements of NAND technology.

Companies like Micron, Intel, SandForce and Spansion are already throwing their support behind ONFI 3.0, applauding the performance improvements and PIN efficiency offered by the new standard.