Input/output Buffer Information Specification (IBIS) is a specification of a method for

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 ...

vendors to provide information about the input/output buffers of their product to their prospective customers without revealing the intellectual property of their implementation and without requiring proprietary encryption keys. From version 5.0, specification contains two separate types of models, "traditional IBIS" and "IBIS-AMI." The traditional model is generated in text format and consists of a number of tables that captures current vs. voltage (IV) and voltage vs. time (Vt) characteristics of the buffer, as well as the values of certain parasitic components. It is a standard data exchange format for exchanging modeling information among

semiconductor A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping level ...

device suppliers,

simulation A simulation is an imitative representation of a process or system that could exist in the real world. In this broad sense, simulation can often be used interchangeably with model. Sometimes a clear distinction between the two terms is made, in ...

software Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications. The history of software is closely tied to the development of digital comput ...

suppliers, and

end user In product development, an end user (sometimes end-user) is a person who ultimately uses or is intended to ultimately use a product. The end user stands in contrast to users who support or maintain the product, such as sysops, system administrato ...

s. Traditional IBIS

models A model is an informative representation of an object, person, or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin , . Models can be divided int ...

are generally used instead of

SPICE In the culinary arts, a spice is any seed, fruit, root, Bark (botany), bark, or other plant substance in a form primarily used for flavoring or coloring food. Spices are distinguished from herbs, which are the leaves, flowers, or stems of pl ...

models to perform various

board Board or Boards may refer to: Flat surface * Lumber, or other rigid material, milled or sawn flat ** Plank (wood) ** Cutting board ** Sounding board, of a musical instrument * Cardboard (paper product) * Paperboard * Fiberboard ** Hardboard, a ...

level

signal integrity Signal integrity or SI is a set of measures of the quality of an electrical signal. In digital electronics, a stream of binary values is represented by a voltage (or current) waveform. However, digital signals are fundamentally analog signal, anal ...

(SI) simulations and timing analyses. IBIS models could be used to verify signal integrity requirements, especially for high-speed products. IBIS-AMI models run in a special-purpose SerDes channel simulator, not in a SPICE-like simulator, and consist of two text files (*.ibs and *.ami) plus a platform-specific

machine code In computer programming, machine code is computer code consisting of machine language instructions, which are used to control a computer's central processing unit (CPU). For conventional binary computers, machine code is the binaryOn nonb ...

executable file (*.dll on Windows, *.so on Linux). IBIS-AMI support statistical and so-called time-domain channel simulations, and three types of IC model ("impulse-only," "GetWave-only," and "dual mode")

History

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 ...

initiated IBIS in the early 1990s. Intel needed to have all of its divisions to present a common standardized model format to its external customers. This prompted Intel to solicit EDA vendors to participate in the development of a common model format. The first IBIS model, version 1.0, was aimed at describing

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 ...

circuits and TTL I/O buffers. As IBIS evolved with the participation of more companies and industry members, an IBIS Open Forum was created to promote the application of IBIS as a simulation tool format and to make sure that a standard exists. Many semiconductor vendors supply IBIS models and many EDA vendors sell IBIS-compliant software tools. In 1995 the IBIS Open Forum teamed with the

American National Standards Institute The American National Standards Institute (ANSI ) is a private nonprofit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organiz ...

Electronic Industries Alliance The Electronic Industries Alliance (EIA; until 1997 Electronic Industries Association) was an American standards organization, standards and trade organization composed as an alliance of trade associations for electronics manufacturers in the ...

(ANSI/EIA). IBIS version 2.1 was the first version released by the new alliance. It added the ability to simulate ECL and PECL buffers as well as differential lines. IBIS 3.2 allows for a package model description along with an electrical board description. IBIS Version 5.0 was ratified by the IBIS Open Forum on August 29, 2008. Compared to the previous version (IBIS 4.2, ANSI/EIA-656-B), it adds a new flow based not on SPICE transient but on a channel simulator (called ''a''lgorithmic ''m''odel application program ''i''nterface or AMI flow), power integrity, and EMC checking features. For power integrity, it uses Touchstone 2.0 S-parameter files with per-port reference impedance specification. Version 5.1 was ratified on August 24, 2012. Important changes included the so-called "flow BIRD" which resolved many ambiguities in the IBIS AMI flow. The IBIS Open Forum became an official subcommittee of

TechAmerica TechAmerica was an American technology trade association that was created in 2009, through the merger of several American trade associations including the AeA and Information Technology Association of America. In May 2014, CompTIA, a nonprofi ...

in January 2009. Upon its purchase of the standards program of TechAmerica in July 2013,

SAE International SAE International is a global professional association and standards organization based in Warrendale, Pennsylvania, United States. Formerly the Society of Automotive Engineers, the organization adopted its current name in 2006 to reflect bot ...

became the parent of IBIS Open Forum. IBIS is an "industry program" within the SAE Industry Technologies Consortia (SAE ITC)

trade association A trade association, also known as an industry trade group, business association, sector association or industry body, is an organization founded and funded by businesses that operate in a specific Industry (economics), industry. Through collabor ...

Evolution

IBIS is an evolving standard with many proposed changes submitted to IBIS Open Forum for consideration. Proposed changes are called BIRDs (Buffer Issue Resolution Documents), a play on the word ''

ibis The ibis () (collective plural ibises; classical plurals ibides and ibes) are a group of long-legged wading birds in the family Threskiornithidae that inhabit wetlands, forests and plains. "Ibis" derives from the Latin and Ancient Greek word f ...

'', a type of bird. Version 6.0 was ratified on September 20, 2013. Changes included an IBIS‐AMI extension for mid-channel repeaters, new parameters for

jitter In electronics and telecommunications, jitter is the deviation from true periodicity of a presumably periodic signal, often in relation to a reference clock signal. In clock recovery applications it is called timing jitter. Jitter is a signifi ...

and noise in IBIS-AMI, and analog buffer modeling improvements. Version 6.1 was ratified on September 11, 2015. Changes included support of PAM-4 in IBIS-AMI, the addition of a new Initial Delay keyword, and additional options for

overclocking In computing, overclocking is the practice of increasing the clock rate of a computer to exceed that certified by the manufacturer. Commonly, operating voltage is also increased to maintain a component's operational stability at accelerated sp ...

. Version 7.0 was ratified on March 15, 2019. Changes included support for Touchstone and IBI-ISS (SPICE) modeling of interconnections, and modeling of back-channel link training protocols using IBIS-AMI models. Work on enhancing the specification can be tracked in the work-in-progress section of the IBIS Open Forum website.

Notes

External links

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{{DEFAULTSORT:Input output Buffer Information Specification Electronic design automation