FAQ
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General Questions
Q.1 What is the mission of the ONFI Workgroup?
The ONFI Workgroup strives to create a common industry standard for the interface used to communicate with NAND Flash components. This increases the supply base for standard components, reduces design time and improves time-to-market for a wide range of NAND-based applications.
Q.2 Is this another card standard?
No, ONFI is not another card standard. It defines the interface to the NAND Flash component itself, while cards often have a controller in addition to the Flash component.
However, ONFI has also defined a connector specification for NAND modules (similar to DRAM DIMMs) for use in applications like caching and SSDs in PC platforms, as well as a managed NAND specification, BA NAND.
Q.3 Does ONFI have any plans to include more member companies in the organization?
The group is actively recruiting and accepting new members. Member benefits include access to draft specifications, participation in workgroups and the ability to influence decision making at the board level. In exchange, member companies contribute resources that jointly advance ONFI efforts.
Q.4 How will the ONFI standard help speed time-to-market for NAND-based products?
ONFI improves the time-to-market in two principal ways:
ONFI simplifies Flash controller design by improving the uniformity of the NAND component interface.
ONFI reduces design time for Flash components in end-use applications and enables the use of a new generation of NAND components by eliminating the need for design or firmware changes.
Q.5 How will developers, OEMs and ODMs benefit from the work done by the ONFI Workgroup?
These groups will benefit from improved uniformity in the behavior of various Flash components offered by multiple sources. OEMs and ODMs will also benefit from the substantial performance increases offered by ONFI 2.1—a 200 MB/s interface that offers four times the performance of legacy NAND.
Q.6 What types of products will ONFI 2.1 be used in?
ONFI improves embedded integration of Flash into a range of products including those that use Flash components today, such as mobile phones, PDAs, MP3 players, notebooks, etc. However, it is likely that the benefits of ONFI 2.1 will first be realized in PC platforms. With the significantly faster speeds that ONFI 2.1 delivers, SSDs and caching solutions will deliver substantive benefits on PC platform workloads.
For more information on products based on ONFI, contact the product suppliers directly. View our Membership page for links to all current member companies.
Q.7 Why was ONFI formed to do this work instead of the work being done in another industry standards organization?
ONFI was formed because the founding companies recognized there was a need in the industry for an open solution to enable more efficient use of a range of NAND devices in product designs.
The ONFI founders felt that an agile, dedicated, single-purpose group would deliver a viable solution more quickly than some of the larger multi-purpose industry organizations. The benefit of a single-purpose and dedicated group can be seen in the rapid development of the ONFI 1.0 specification, which was published less than eight months after the group’s formation.
Now that ONFI has developed the baseline specifications, we're partnering with JEDEC to enhance the reach of the specifications.
Q.8 Who's involved in your partnership with JEDEC to expand the reach of the ONFI specifications?
ONFI is working with JEDEC through a joint task group. Participation in the joint task group is open to all ONFI and JEDEC members.
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Technical Questions
Q.1 What is the difference between the ONFI 1.0 and 2.0 specs?
The key difference between ONFI 1.0 and 2.0 is speed: we’ve increased the maximum interface speed to 133 MB/s from the legacy NAND interface maximum speed of 50 MB/s. ONFI put in place forward-looking features to enable future high speed generations that may reach 400 MB/s in the third generation.
The Workgroup has also created an addendum specification that allows a “block abstraction” capability. The block abstraction (BA) specification manages different NAND Flash components, relieving the host from dealing with ECC, bad block tracking, and other low level NAND management tasks.
An addendum specification for a NAND DIMM connector specification was published in April of 2008.
Q.2 What is the difference between the ONFI 2.0 and 2.1 specs?
The key difference in the updated spec is speed: we've increased the maximum interface speed to 166 MB/s and 200 MB/s from the 2.0 interface maximum speed of 133 MB/s. We also included improvements to power management and ECC information.
For details, see our ONFI 2.1 presentation.
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Roadmap Questions
Q.1 When were the ONFI specifications released?
ONFI released the final 1.0 specification on December 28, 2006. The 0.9 draft of the ONFI 2.0 specification was made available to member companies on November 7, 2007. The final ONFI 2.0 specification was published in February of 2008 and updated with a 2.1 release in January of 2009.
The BA NAND specification was released in July of 2007.
The NAND DIMM connector specification (released in April of 2008) is intended to enable easy use of NAND in computing platforms and other applications.
Q.2 When will the next revision of the specification be complete? What improvements will be made in the next generation development efforts?
The working group's immediate plans are to work on updating the BA NAND specification and the ONFI 2.2 spec. The 2.2 spec is expected to include additional commands and ICC measurement techniques.
As this technology develops with ONFI and JEDEC working together throughout 2009, the next big jump will result in an ONFI 3.0 spec in mid-2010 that will aim for 400 MB/s speed capabilities.