The Open NAND Flash Interface Working Group (ONFI or ONFi with a lower case "i") is a

consortium A consortium () is an association of two or more individuals, companies, organizations, or governments (or any combination of these entities) with the objective of participating in a common activity or pooling their resources for achieving a ...

of technology companies working to develop

open standards An open standard is a standard that is openly accessible and usable by anyone. It is also a common prerequisite that open standards use an open license that provides for extensibility. Typically, anybody can participate in their development due to ...

for NAND

flash memory Flash memory is an Integrated circuit, electronic Non-volatile memory, non-volatile computer memory storage medium that can be electrically erased and reprogrammed. The two main types of flash memory, NOR flash and NAND flash, are named for t ...

and devices that communicate with them. The formation of ONFI was announced at the

Intel Developer Forum The Intel Developer Forum (IDF) was a biannual gathering of technologists to discuss Intel products and products based on Intel products. The first IDF was held in 1997. To emphasize the importance of China, the Spring 2007 IDF was held in Beijin ...

in March 2006.

History

The group's goals did ''not'' include the development of a new consumer flash

memory card A memory card is an electronic data storage device used for storing digital information, typically using flash memory. These are commonly used in digital portable electronic devices, such as digital cameras as well as in many early games conso ...

format. Rather, ONFI seeks to standardize the low-level interface to raw NAND flash chips, which are the most widely used form of

non-volatile Non-volatile memory (NVM) or non-volatile storage is a type of computer memory that can retain stored information even after power is removed. In contrast, volatile memory needs constant power in order to retain data. Non-volatile memory typ ...

memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembe ...

integrated circuit An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components a ...

s (chips); in 2006, nearly one trillion

MiB The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable un ...

of flash memory was incorporated into consumer electronics, and production was expected to double by 2007. , NAND flash memory chips from most vendors used similar packaging, had similar

pinout In electronics, a pinout (sometimes written "pin-out") is a cross-reference between the contacts, or ''pins'', of an electrical connector or electronic component, and their functions. "Pinout" now supersedes the term "basing diagram" which was the ...

s, and accepted similar sets of low-level commands. As a result, when more capable and inexpensive models of NAND flash become available, product designers can incorporate them without major design changes. However, "similar" operation is not optimal: See section "The Curse of Similarity" in this white paper by Arun Kamat of Hynix. subtle differences in timing and command set mean that products must be thoroughly

debug In engineering, debugging is the process of finding the root cause, workarounds, and possible fixes for bugs. For software, debugging tactics can involve interactive debugging, control flow analysis, log file analysis, monitoring at the ap ...

ged and tested when a new model of flash chip is used in them. When a

flash controller A flash memory controller (or flash controller) manages data stored on flash memory (usually NAND flash) and communicates with a computer or electronic device. Flash memory controllers can be designed for operating in low duty-cycle environments ...

is expected to operate with various NAND flash chips, it must store a table of them in its

firmware In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, h ...

so that it knows how to deal with differences in their interfaces. This increases the complexity and

time-to-market In commerce, time to market (TTM) is the length of time it takes from a product being conceived until its being available for sale. The reason that time to market is so important is that being late erodes the addressable market into which produ ...

of flash-based devices, and means they are likely to be incompatible with future models of NAND flash, unless and until their firmware is updated. Thus, one of the main motivations for standardization of NAND flash was to make it easier to switch between NAND chips from different producers, thereby permitting faster development of NAND-based products and lower prices via increased

competition Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indi ...

among manufacturers. By 2006, NAND flash became increasingly a

commodity In economics, a commodity is an economic goods, good, usually a resource, that specifically has full or substantial fungibility: that is, the Market (economics), market treats instances of the good as equivalent or nearly so with no regard to w ...

product,See thi
presentation
by Amber Huffman and Michael Abraham of

Micron The micrometre (English in the Commonwealth of Nations, Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a uni ...

. like

SDRAM Synchronous dynamic random-access memory (synchronous dynamic RAM or SDRAM) is any DRAM where the operation of its external pin interface is coordinated by an externally supplied clock signal. DRAM integrated circuits (ICs) produced from the ...

hard disk A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating hard disk drive platter, pla ...

drives. It is incorporated into many

personal computer A personal computer, commonly referred to as PC or computer, is a computer designed for individual use. It is typically used for tasks such as Word processor, word processing, web browser, internet browsing, email, multimedia playback, and PC ...

and consumer electronics products such as

USB flash drive A flash drive (also thumb drive, memory stick, and pen drive/pendrive) is a data storage device that includes flash memory with an integrated USB interface. A typical USB drive is removable, rewritable, and smaller than an optical disc, and u ...

MP3 player A portable media player (PMP) or digital audio player (DAP) is a portable consumer electronics device capable of storing and playing digital media such as audio, images, and video files. Normally they refer to small, battery-powered devices ...

s, and

solid-state drive A solid-state drive (SSD) is a type of solid-state storage device that uses integrated circuits to store data persistently. It is sometimes called semiconductor storage device, solid-state device, or solid-state disk. SSDs rely on non- ...

s. Product designers wanted newer NAND flash chips, for example, to be as easily interchangeable as hard disks from different manufacturers.

Historical similarities

The effort to standardize NAND flash may be compared to earlier standardization of

electronic component An electronic component is any basic discrete electronic device or physical entity part of an electronic system used to affect electrons or their associated fields. Electronic components are mostly industrial products, available in a singula ...

s. For example, the

7400 series The 7400 series is a popular logic family of transistor–transistor logic (TTL) integrated circuits (ICs). In 1964, Texas Instruments introduced the SN5400 series of logic chips, in a ceramic semiconductor package. A low-cost plastic package ...

of TTL digital

integrated circuits An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components a ...

were originally produced by

Texas Instruments Texas Instruments Incorporated (TI) is an American multinational semiconductor company headquartered in Dallas, Texas. It is one of the top 10 semiconductor companies worldwide based on sales volume. The company's focus is on developing analog ...

, but had become a ''de facto'' standard family by the late 1970s. These ICs are manufactured as commodity parts by a number of different vendors. This has allowed designers to freely mix 7400 components from different vendors—and even to mix components based on different

logic families In computer engineering, a logic family is one of two related concepts: * A logic family of monolithic digital integrated circuit devices is a group of electronic logic gates constructed using one of several different designs, usually with compati ...

, once the 74HCT sub-family become available (consisting of

CMOS Complementary metal–oxide–semiconductor (CMOS, pronounced "sea-moss ", , ) is a type of MOSFET, metal–oxide–semiconductor field-effect transistor (MOSFET) semiconductor device fabrication, fabrication process that uses complementary an ...

components with TTL-compatible logic levels).

Members

The ONFI consortium included manufacturers of NAND flash memory such as Hynix,

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, and Delaware General Corporation Law, incorporated in Delaware. Intel designs, manufactures, and sells computer compo ...

Micron Technology Micron Technology, Inc. is an American producer of computer memory and computer data storage including dynamic random-access memory, flash memory, and solid-state drives (SSDs). It is headquartered in Boise, Idaho. Micron's consumer produc ...

, Phison,

Western Digital Western Digital Corporation is an American data storage company headquartered in San Jose, California. Established in 1970, the company is one of the world's largest manufacturers of hard disk drives (HDDs). History 1970s Western Digital ...

Sony is a Japanese multinational conglomerate (company), conglomerate headquartered at Sony City in Minato, Tokyo, Japan. The Sony Group encompasses various businesses, including Sony Corporation (electronics), Sony Semiconductor Solutions (i ...

and Spansion.

Samsung Samsung Group (; stylised as SΛMSUNG) is a South Korean Multinational corporation, multinational manufacturing Conglomerate (company), conglomerate headquartered in the Samsung Town office complex in Seoul. The group consists of numerous a ...

, the world's largest manufacturer of NAND flash, was absent in 2006. Vendors of NAND flash-based consumer electronics and computing products are also members.

Specifications

ONFI produced

specification A specification often refers to a set of documented requirements to be satisfied by a material, design, product, or service. A specification is often a type of technical standard. There are different types of technical or engineering specificati ...

s for standard interface to NAND flash chips. Version 1.0 of this specification was released on December 28, 2006, and made available at no cost from the ONFI web site. Samsung was still not a participant. It specified: * a standard physical interface (

) for NAND flash in TSOP-48, WSOP-48,

LGA LaGuardia Airport ( ) – colloquially known as LaGuardia or simply LGA – is a civil airport in East Elmhurst, Queens, New York City, situated on the northwestern shore of Long Island, bordering Flushing Bay. Covering , the facility wa ...

-52, and BGA-63 packages * a standard mechanism for NAND chips to identify themselves and describe their capabilities (comparable to the

Serial Presence Detect In computing, serial presence detect (SPD) is a standardized way to automatically access information about a memory module. Earlier 72-pin SIMMs included five pins that provided five bits of ''parallel presence detect'' (PPD) data, but the 168- ...

ion feature of

modules) * a standard command set for reading, writing, and erasing NAND flash * standard timing requirements for NAND flash * improved performance via a standard implementation of read

cache Cache, caching, or caché may refer to: Science and technology * Cache (computing), a technique used in computer storage for easier data access * Cache (biology) or hoarding, a food storing behavior of animals * Cache (archaeology), artifacts p ...

and increased concurrency for NAND flash operations * improved data integrity by allowing optional

error-correcting code In computing, telecommunication, information theory, and coding theory, forward error correction (FEC) or channel coding is a technique used for controlling errors in data transmission over unreliable or noisy communication channels. The centra ...

(ECC) features A verification product was announced in June 2009. Version 2.3 was published in August 2010. It included a protocol called EZ-NAND that hid ECC details. Version 3.0 was published in March 2011. It required fewer chip-enable pins enabling more efficient

printed circuit board A printed circuit board (PCB), also called printed wiring board (PWB), is a Lamination, laminated sandwich structure of electrical conduction, conductive and Insulator (electricity), insulating layers, each with a pattern of traces, planes ...

routing. A standard developed jointly with the

JEDEC The Joint Electron Device Engineering Council (JEDEC) Solid State Technology Association is a consortium of the semiconductor industry headquartered in Arlington County, Virginia, Arlington, United States. It has over 300 members and is focused ...

was published in October 2012. Version 3.1, published in october of 2012, includes errata to the original ONFI 3.0 specification, adds LUN SET/GET Features commands, and implements additional data setup and hold values for NV-DDR2 interface. Version 3.2, published on July 23, 2013, raised the data rate to 533 MB/s. Version 4.0, published on April 17, 2014, introduced the NV-DDR3 interface increases the maximum switching speed from 533 MB/s to 800 MB/s, providing a performance boost of up to 50% for high performance applications enabled by solid-state NAND storage components. Version 4.1, published on December 12, 2017, extends NV-DDR3 I/O speeds to 1066 MT/s and 1200MT/s. For better signaling performance, ONFI 4.1 adds Duty Cycle Correction (DCC), Read and Write Training for speeds greater than 800MT/s, support for lower pin cap devices with 37.5 Ohms default output resistance, and devices which require data burst exit and restart for long data input and output pauses. For lower power, 2.5V Vcc support is added. ONFI 4.1 also includes errata to the ONFI 4.0 specification. Version 4.2, published on February 12, 2020, extends NV-DDR3 I/O speeds to 1333MT/s, 1466MT/s and 1600MT/s. The BGA-252b four channel package is introduced which has a smaller footprint than the existing BGA-272b four channel package. To enable higher IOPS multi-plane operations, addressing restrictions related to multi-plane operations are relaxed. Version 5.0, Published in May 2021, ONFI5.0 extends NV-DDR3 I/O speeds up to 2400MT/s. A new NV-LPDDR4 lower power interface is introduced with speeds up to 2400MT/s. With the NV-LPDDR4 interface, an optional Data Bus Inversion (DBI) feature is defined. New smaller footprint BGA-178b, BGA-154b and BGA-146b packages are added. ONFI5.0 also includes other errata related to the ONFI4.2 specification.

Block Abstracted NAND

ONFI created the Block Abstracted NAND addendum specification to simplify host controller design by relieving the host of the complexities of ECC, bad block management, and other low-level NAND management tasks. The ONFI Block Abstracted NAND revision 1.1 specification adds the high speed source synchronous interface, which provides up to a 5X improvement in bandwidth compared with the traditional asynchronous NAND interface.

NAND Connector

The NAND Connector Specification was ratified in April 2008. It specifies a standardized connection for NAND modules (similar to DRAM DIMMs) for use in applications like caching and

s (SSDs) in PC platforms.

References

External links

* {{authority control Computer memory Non-volatile memory Standards organizations in the United States Technology trade associations Organizations based in Oregon