IEEE 1394 is an
interface standard for a
serial bus
In telecommunication and data transmission, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are ...
for high-speed communications and
isochronous
A sequence of events is isochronous if the events occur regularly, or at equal time intervals. The term ''isochronous'' is used in several technical contexts, but usually refers to the primary subject maintaining a constant period or interval ( ...
real-time data transfer. It was developed in the late 1980s and early 1990s by
Apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, where its wild ancestor, ' ...
in cooperation with a number of companies, primarily
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professiona ...
and
Panasonic
formerly between 1935 and 2008 and the first incarnation of between 2008 and 2022, is a major Japanese multinational conglomerate corporation, headquartered in Kadoma, Osaka. It was founded by Kōnosuke Matsushita in 1918 as a lightbulb ...
. Apple called the interface FireWire. It is also known by the brand names i.LINK (Sony), and Lynx (
Texas Instruments
Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globa ...
).
The copper cable used in its most common implementation can be up to long. Power and data is carried over this cable, allowing devices with moderate power requirements to operate without a separate power supply. FireWire is also available in
Cat 5
Category 5 cable (Cat 5) is a twisted pair cable for computer networks. Since 2001, the variant commonly in use is the Category 5e specification (Cat 5e). The cable standard provides performance of up to 100 MHz and is ...
and
optical fiber
An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass ( silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a mea ...
versions.
The 1394 interface is comparable to
USB
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad ...
. USB was developed subsequently and gained much greater market share. USB requires a host controller whereas IEEE 1394 is cooperatively managed by the connected devices.
History and development
![Firewire PCI VIA VT6306](https://upload.wikimedia.org/wikipedia/commons/f/fa/Firewire_PCI_VIA_VT6306.jpg)
FireWire is Apple's name for the IEEE 1394 High Speed Serial Bus. Its development was initiated by Apple
in 1986,
and developed by the IEEE P1394 Working Group, largely driven by contributions from
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professiona ...
(102 patents), Apple (58 patents), and
Panasonic
formerly between 1935 and 2008 and the first incarnation of between 2008 and 2022, is a major Japanese multinational conglomerate corporation, headquartered in Kadoma, Osaka. It was founded by Kōnosuke Matsushita in 1918 as a lightbulb ...
(46 patents), in addition to contributions made by engineers from
Philips
Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters i ...
,
LG Electronics
LG Electronics Inc. () is a South Korean multinational electronics company headquartered in Yeouido-dong, Seoul, South Korea. LG Electronics is a part of LG Corporation, the fourth largest '' chaebol'' in South Korea, and often considered a ...
,
Toshiba
, commonly known as Toshiba and stylized as TOSHIBA, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. Its diversified products and services include power, industrial and social infrastructure systems, ...
,
Hitachi,
Canon
Canon or Canons may refer to:
Arts and entertainment
* Canon (fiction), the conceptual material accepted as official in a fictional universe by its fan base
* Literary canon, an accepted body of works considered as high culture
** Western ca ...
,
INMOS/SGS
Thomson Thomson may refer to:
Names
* Thomson (surname), a list of people with this name and a description of its origin
* Thomson baronets, four baronetcies created for persons with the surname Thomson
Businesses and organizations
* SGS-Thomson Mic ...
(now
STMicroelectronics),
and
Texas Instruments
Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globa ...
.
IEEE 1394 is a serial
bus
A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a road vehicle that carries significantly more passengers than an average car or van. It is most commonly used in public transport, but is also in use for cha ...
architecture for high-speed data transfer. FireWire is a
serial bus, meaning that information is transferred one bit at a time.
Parallel
Parallel is a geometric term of location which may refer to:
Computing
* Parallel algorithm
* Parallel computing
* Parallel metaheuristic
* Parallel (software), a UNIX utility for running programs in parallel
* Parallel Sysplex, a cluster of ...
buses utilize a number of different physical connections, and as such are usually more costly and typically heavier.
IEEE 1394 fully supports both isochronous and
asynchronous applications.
Apple intended FireWire to be a serial replacement for the parallel
SCSI bus, while providing connectivity for digital audio and video equipment. Apple's development began in the late 1980s, later presented to the IEEE,
and was completed in January 1995. In 2007, IEEE 1394 was a composite of four documents: the original IEEE Std. 1394–1995, the
IEEE Std. 1394a-2000 amendment, the
IEEE Std. 1394b-2002 amendment, and the
IEEE Std. 1394c-2006 amendment. On June 12, 2008, all these amendments as well as errata and some technical updates were incorporated into a superseding standard, IEEE Std. 1394–2008.
Apple first included onboard FireWire in some of its 1999 Macintosh models (though it had been a build-to-order option on some models since 1997), and most Apple Macintosh computers manufactured in the years 2000 through 2011 included FireWire ports. However, in February 2011 Apple introduced the first commercially available computer with
Thunderbolt
A thunderbolt or lightning bolt is a symbolic representation of lightning when accompanied by a loud thunderclap. In Indo-European mythology, the thunderbolt was identified with the 'Sky Father'; this association is also found in later Hel ...
. Apple released its last computers with FireWire in 2012. By 2014, Thunderbolt had become a standard feature across Apple's entire line of computers (later with the exception of the 12-inch MacBook introduced in 2015, which featured only a sole USB-C port) effectively becoming the
spiritual successor to FireWire in the Apple ecosystem. Apple's last products with FireWire, the
Thunderbolt Display and 2012 13-inch
MacBook Pro, were discontinued in 2016. Apple still sells a Thunderbolt to FireWire Adapter, which provides one FireWire 800 port. A separate adapter is required to use it with Thunderbolt 3.
Sony's implementation of the system, ''i.LINK'', used a smaller connector with only four signal conductors, omitting the two conductors that provide power for devices in favor of a separate power connector. This style was later added into the 1394a amendment.
[ This port is sometimes labeled ''S100'' or ''S400'' to indicate speed in Mbit/s.
The system was commonly used to connect data storage devices and DV (digital video) cameras, but was also popular in industrial systems for ]machine vision
Machine vision (MV) is the technology and methods used to provide imaging-based automatic inspection and analysis for such applications as automatic inspection, process control, and robot guidance, usually in industry. Machine vision refers to ...
and professional audio
Professional audio, abbreviated as pro audio, refers to both an activity and a category of high quality, studio-grade audio equipment. Typically it encompasses sound recording, sound reinforcement system setup and audio mixing, and studio mu ...
systems. Many users preferred it over the more common USB 2.0
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad ...
for its then greater effective speed and power distribution capabilities. Benchmarks show that the sustained data transfer rates are higher for FireWire than for USB 2.0, but lower than USB 3.0
USB 3.0, released in November 2008, is the third major version of the Universal Serial Bus (USB) standard for interfacing computers and electronic devices. Among other improvements, USB 3.0 adds the new transfer rate referred to as '' ...
. Results are marked on Apple Mac OS X
macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and la ...
but more varied on Microsoft Windows.
Patent considerations
Implementation of IEEE 1394 is said to require use of 261 issued international patents held by ten corporations. Use of these patents requires licensing; use without license generally constitutes patent infringement. Companies holding IEEE 1394 IP formed a patent pool
In patent law, a patent pool is a consortium of at least two companies agreeing to cross-license patents relating to a particular technology. The creation of a patent pool can save patentees and licensees time and money, and, in case of blocking ...
with MPEG LA
MPEG LA is an American company based in Denver, Colorado that licenses patent pools covering essential patents required for use of the MPEG-2, MPEG-4, IEEE 1394, VC-1, ATSC, MVC, MPEG-2 Systems, AVC/H.264 and HEVC standards.
History
MPEG LA ...
, LLC as the license administrator, to whom they licensed patents. MPEG LA sublicenses these patents to providers of equipment implementing IEEE 1394. Under the typical patent pool license, a royalty of US$0.25 per unit is payable by the manufacturer upon the manufacture of each 1394 finished product; no royalties are payable by users.
The last of the patents, MY 120654 by Sony, expired on November 30, 2020. , the following are patent holders of the IEEE 1394 standard, as listed in the patent pool
In patent law, a patent pool is a consortium of at least two companies agreeing to cross-license patents relating to a particular technology. The creation of a patent pool can save patentees and licensees time and money, and, in case of blocking ...
managed by MPEG LA
MPEG LA is an American company based in Denver, Colorado that licenses patent pools covering essential patents required for use of the MPEG-2, MPEG-4, IEEE 1394, VC-1, ATSC, MVC, MPEG-2 Systems, AVC/H.264 and HEVC standards.
History
MPEG LA ...
.
A person or company may review the actual 1394 Patent Portfolio License upon request to MPEG LA. MPEG LA does not provide assurance of protection to licensees beyond its own patents. At least one formerly licensed patent is known to have been removed from the pool, and other hardware patents exist that reference IEEE 1394.
The 1394 High Performance Serial Bus Trade Association (the ''1394 TA'') was formed to aid the marketing of IEEE 1394. Its bylaws prohibit dealing with intellectual property issues. The 1394 Trade Association operates on an individual no cost membership basis to further enhancements to 1394 standards. The Trade Association also is the library source for all 1394 documentation and standards available.
Technical specifications
FireWire can connect up to 63 peripherals in a tree or daisy-chain topology
In mathematics, topology (from the Greek words , and ) is concerned with the properties of a geometric object that are preserved under continuous deformations, such as stretching, twisting, crumpling, and bending; that is, without closing ...
(as opposed to Parallel SCSI's electrical bus topology). It allows peer-to-peer
Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network. They are said to form a peer-to-peer ...
device communication — such as communication between a scanner and a printer — to take place without using system memory or the CPU. FireWire also supports multiple host controllers per bus. It is designed to support plug and play
In computing, a plug and play (PnP) device or computer bus is one with a specification that facilitates the recognition of a hardware component in a system without the need for physical device configuration or user intervention in resolving resou ...
and hot swapping
Hot swapping is the replacement or addition of components to a computer system without stopping, shutting down, or rebooting the system; hot plugging describes the addition of components only. Components which have such functionality are said ...
. The copper cable it uses in its most common implementation can be up to long and is more flexible than most parallel SCSI cables. In its six-conductor or nine-conductor variations, it can supply up to 45 watts of power per port at up to 30 volts, allowing moderate-consumption devices to operate without a separate power supply.
FireWire devices implement the ISO/IEC 13213 ''configuration ROM
Rom, or ROM may refer to:
Biomechanics and medicine
* Risk of mortality, a medical classification to estimate the likelihood of death for a patient
* Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac
* ...
'' model for device configuration and identification, to provide plug-and-play
In computing, a plug and play (PnP) device or computer bus is one with a specification that facilitates the recognition of a hardware component in a system without the need for physical device configuration or user intervention in resolving reso ...
capability. All FireWire devices are identified by an IEEE EUI-64
A media access control address (MAC address) is a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment. This use is common in most IEEE 802 networking tech ...
unique identifier in addition to well-known codes indicating the type of device and the protocols
Protocol may refer to:
Sociology and politics
* Protocol (politics), a formal agreement between nation states
* Protocol (diplomacy), the etiquette of diplomacy and affairs of state
* Etiquette, a code of personal behavior
Science and technology ...
it supports.
FireWire devices are organized at the bus in a tree topology. Each device has a unique self-ID. One of the nodes is elected root node and always has the highest ID. The self-IDs are assigned during the self-ID process, which happens after each bus resets. The order in which the self-IDs are assigned is equivalent to traversing the tree depth-first
Depth-first search (DFS) is an algorithm for traversing or searching tree or graph data structures. The algorithm starts at the root node (selecting some arbitrary node as the root node in the case of a graph) and explores as far as possible alon ...
, post-order.
FireWire is capable of safely operating critical systems due to the way multiple devices interact with the bus and how the bus allocates bandwidth to the devices. FireWire is capable of both asynchronous and isochronous transfer methods at once. Isochronous data transfers are transfers for devices that require continuous, guaranteed bandwidth. In an aircraft, for instance, isochronous devices include control of the rudder
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally air or water). On an aircraft the rudder is used primarily to counter adve ...
, mouse operations and data from pressure sensors outside the aircraft. All these elements require constant, uninterrupted bandwidth. To support both elements, FireWire dedicates a certain percentage to isochronous data and the rest to asynchronous data. In IEEE 1394, 80% of the bus is reserved for isochronous cycles, leaving asynchronous data with a minimum of 20% of the bus.
Encoding scheme
FireWire uses Data/Strobe encoding (D/S encoding). In D/S encoding, two non-return-to-zero
In telecommunication, a non-return-to-zero (NRZ) line code is a binary code in which ones are represented by one significant condition, usually a positive voltage, while zeros are represented by some other significant condition, usually a negati ...
(NRZ) signals are used to transmit the data with high reliability. The NRZ signal sent is fed with the clock signal through an XOR gate
XOR gate (sometimes EOR, or EXOR and pronounced as Exclusive OR) is a digital logic gate that gives a true (1 or HIGH) output when the number of true inputs is odd. An XOR gate implements an exclusive or (\nleftrightarrow) from mathematical log ...
, creating a strobe signal. This strobe is then put through another XOR gate along with the data signal to reconstruct the clock. This in turn acts as the bus's phase-locked loop
A phase-locked loop or phase lock loop (PLL) is a control system that generates an output signal whose phase is related to the phase of an input signal. There are several different types; the simplest is an electronic circuit consisting of a ...
for synchronization purposes.
Arbitration
The process of the bus deciding which node gets to transmit data at what time is known as arbitration. Each arbitration round lasts about 125 microseconds. During the round, the root node (device nearest the processor) sends a cycle start packet. All nodes requiring data transfer respond, with the closest node winning. After the node is finished, the remaining nodes take turns in order. This repeats until all the devices have used their portion of the 125 microseconds, with isochronous transfers having priority.
Standards and versions
The previous standards and its three published amendments are now incorporated into a superseding standard, IEEE 1394-2008. The features individually added give a good history on the development path.
FireWire 400 (IEEE 1394-1995)
The original release of IEEE 1394-1995 specified what is now known as FireWire 400. It can transfer data between devices at 100, 200, or 400 Mbit/s
In telecommunications, data-transfer rate is the average number of bits ( bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are mu ...
half-duplex
A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow ...
data rates (the actual transfer rates are 98.304, 196.608, and 393.216 Mbit/s, i.e., 12.288, 24.576 and 49.152 MB/s
In telecommunications, data-transfer rate is the average number of bits ( bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are mu ...
respectively).[ These different transfer modes are commonly referred to as S100, S200, and S400.
Cable length is limited to , although up to 16 cables can be ]daisy chain
Daisy chain may refer to:
* Daisy chain, a garland created from daisy flowers
* Daisy chain (climbing), a type of strap
* Daisy chain (electrical engineering), a wiring scheme
* Daisy chain (fishing), a type of fishing lure
* Daisy chain (knot), ...
ed using active repeaters; external hubs or internal hubs are often present in FireWire equipment. The S400 standard limits any configuration's maximum cable length to . The 6-conductor connector is commonly found on desktop computers and can supply the connected device with power.
The 6-conductor powered connector, now referred to as an alpha connector, adds power output to support external devices. Typically a device can pull about 7 to 8 watts from the port; however, the voltage varies significantly from different devices. Voltage is specified as unregulated and should nominally be about 25 volts (range 24 to 30). Apple's implementation on laptops is typically related to battery power and can be as low as 9 V.
Improvements (IEEE 1394a-2000)
An amendment, IEEE 1394a, was released in 2000,[ tp://ftp.t10.org/1394/P1394a/Drafts/P1394a50.pdf P1394a Draft 5.0available.] which clarified and improved the original specification. It added support for asynchronous streaming, quicker bus reconfiguration, packet concatenation, and a power-saving suspend mode.
IEEE 1394a offers a couple of advantages over the original IEEE 1394–1995. 1394a is capable of arbitration accelerations, allowing the bus to accelerate arbitration cycles to improve efficiency. It also allows for arbitrated short bus reset, in which a node can be added or dropped without causing a big drop in isochronous transmission.
1394a also standardized the 4-conductor alpha connector developed by Sony and trademarked as ''i.LINK'', already widely in use on consumer devices such as camcorders, most PC laptops, a number of PC desktops, and other small FireWire devices. The 4-conductor connector is fully data-compatible with 6-conductor alpha interfaces but lacks power connectors.
FireWire 800 (IEEE 1394b-2002)
IEEE 1394b-2002 introduced FireWire 800 (Apple's name for the 9-conductor ''S800 bilingual'' version of the IEEE 1394b standard). This specification and corresponding products allow a transfer rate of 786.432 Mbit/s full-duplex
A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow ...
via a new encoding scheme termed beta mode. It is backwards compatible with the slower rates and 6-conductor alpha connectors of FireWire 400. However, while the IEEE 1394a and IEEE 1394b standards are compatible, FireWire 800's connector, referred to as a beta connector, is different from FireWire 400's alpha connectors, making legacy cables incompatible. A bilingual cable allows the connection of older devices to the newer port. In 2003, Apple was the first to introduce commercial products with the new connector.
The full IEEE 1394b specification supports data rates up to 3200 Mbit/s (i.e., 400 MB/s) over beta-mode or optical connections up to in length. Standard Category 5e unshielded twisted pair
Twisted pair cabling is a type of wiring used for communications in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a single conductor or an untwisted ba ...
supports at S100. The original 1394 and 1394a standards used data/strobe (D/S) encoding (renamed to ''alpha mode'') with the cables, while 1394b added a data encoding scheme called 8b/10b
In telecommunications, 8b/10b is a line code that maps 8-bit words to 10-bit symbols to achieve DC balance and bounded disparity, and at the same time provide enough state changes to allow reasonable clock recovery. This means that the diffe ...
referred to as ''beta mode''.
Beta mode is based on 8b/10b
In telecommunications, 8b/10b is a line code that maps 8-bit words to 10-bit symbols to achieve DC balance and bounded disparity, and at the same time provide enough state changes to allow reasonable clock recovery. This means that the diffe ...
(from Gigabit Ethernet
In computer networking, Gigabit Ethernet (GbE or 1 GigE) is the term applied to transmitting Ethernet frames at a rate of a gigabit per second. The most popular variant, 1000BASE-T, is defined by the IEEE 802.3ab standard. It came into use ...
, also used for many other protocols). 8b/10b encoding involves expanding an 8-bit data word into 10 bits, with the extra bits after the 5th and 8th data bits. The partitioned data is sent through a Running Disparity calculator function. The Running Disparity calculator attempts to keep the number of 1s transmitted equal to 0s, thereby assuring a DC-balanced signal. Then, the different partitions are sent through a 5b/6b encoder for the 5-bit partition and a 3b/4b encoder for the 3-bit partition. This gives the packet the ability to have at least two 1s, ensuring synchronization of the PLL at the receiving end to the correct bit boundaries for reliable transfer. An additional function of the coding scheme is to support the arbitration for bus access and general bus control. This is possible due to the ''surplus'' symbols afforded by the 8b/10b expansion. (While 8-bit symbols can encode a maximum of 256 values, 10-bit symbols permit the encoding of up to 1024.) Symbols invalid for the current state of the receiving PHY
PHY is an abbreviation for the physical layer of the OSI model and refers to the circuitry required to implement physical layer functions.
PHY or Phy may also refer to:
* Phy, the drug methadone
* Phetchabun Airport (IATA code), Thailand
See ...
indicate data errors.
FireWire S800T (IEEE 1394c-2006)
IEEE 1394c-2006 was published on June 8, 2007. It provided a major technical improvement, namely new port specification that provides 800 Mbit/s over the same 8P8C (Ethernet) connectors with Category 5e cable
Category 5 cable (Cat 5) is a twisted pair cable for computer networks. Since 2001, the variant commonly in use is the Category 5e specification (Cat 5e). The cable standard provides performance of up to 100 MHz and is ...
, which is specified in IEEE 802.3 clause 40 ( gigabit Ethernet over copper twisted pair) along with a corresponding automatic negotiation that allows the same port to connect to either IEEE Std 1394 or IEEE 802.3 (Ethernet
Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1 ...
) devices.
Though the potential for a combined Ethernet and FireWire 8P8C port is intriguing, , no products or chipsets include this capability.
FireWire S1600 and S3200
In December 2007, the 1394 Trade Association announced that products would be available before the end of 2008 using the S1600 and S3200 modes that, for the most part, had already been defined in 1394b and were further clarified in IEEE Std. 1394–2008. The 1.572864 Gbit/s and 3.145728 Gbit/s devices use the same 9-conductor beta connectors as the existing FireWire 800 and are fully compatible with existing S400 and S800 devices. It competes with USB 3.0
USB 3.0, released in November 2008, is the third major version of the Universal Serial Bus (USB) standard for interfacing computers and electronic devices. Among other improvements, USB 3.0 adds the new transfer rate referred to as '' ...
.
S1600 (Symwave) and S3200 (Dap Technology) development units have been made, however because of FPGA technology DapTechnology targeted S1600 implementations first with S3200 not becoming commercially available until 2012.
Steve Jobs declared FireWire dead in 2008. , there were few S1600 devices released, with a Sony camera being the only notable user.
Future enhancements (including P1394d)
A project named IEEE P1394d was formed by the IEEE on March 9, 2009 to add single mode fiber
In fiber-optic communication, a single-mode optical fiber (SMF), also known as fundamental- or mono-mode, is an optical fiber designed to carry only a single mode (electromagnetism), mode of light - the transverse mode. Modes are the possible s ...
as an additional transport medium to FireWire. The project was withdrawn in 2013.
Other future iterations of FireWire were expected to increase speed to 6.4 Gbit/s and additional connectors such as the small multimedia interface.
Operating system support
Full support for IEEE 1394a and 1394b is available for Microsoft Windows, FreeBSD, Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, w ...
, Apple Mac OS 8.6
Mac OS 8 is an operating system that was released by Apple Computer on July 26, 1997. It includes the largest overhaul of the classic Mac OS experience since the release of System 7, approximately six years before. It places a greater emphasis ...
through Mac OS 9, NetBSD, and Haiku
is a type of short form poetry originally from Japan. Traditional Japanese haiku consist of three phrases that contain a ''kireji'', or "cutting word", 17 '' on'' (phonetic units similar to syllables) in a 5, 7, 5 pattern, and a ''kigo'', or s ...
.
In Windows XP, a degradation in performance of 1394 devices may have occurred with installation of Service Pack 2. This was resolved in Hotfix 885222 and in SP3. Some FireWire hardware manufacturers also provide custom device drivers that replace the Microsoft OHCI host adapter driver stack, enabling S800-capable devices to run at full 800 Mbit/s transfer rates on older versions of Windows (XP SP2 w/o Hotfix 885222) and Windows Vista. At the time of its release, Microsoft Windows Vista
Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...
supported only 1394a, with assurances that 1394b support would come in the next service pack. Service Pack 1 for Microsoft Windows Vista
Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...
has since been released, however the addition of 1394b support is not mentioned anywhere in the release documentation. The 1394 bus driver was rewritten for Windows 7 to provide support for higher speeds and alternative media.
In Linux, support was originally provided by libraw1394 making direct communication between user space and IEEE 1394 buses. Subsequently, a new kernel driver stack, nicknamed JuJu, has been implemented.
Cable TV system support
Under FCC Code 47 CFR 76.640 section 4, subsections 1 and 2, Cable TV providers (in the US, with digital systems) must, upon request of a customer, have provided a high-definition capable cable box with a functional FireWire interface. This applied only to customers leasing high-definition capable cable boxes from their cable provider after April 1, 2004.
The interface can be used to display or record Cable TV, including HDTV programming. In June 2010, the FCC issued an order that permitted set-top boxes to include IP-based interfaces in place of FireWire.
Comparison with USB
While both technologies provide similar end results, there are fundamental differences between USB
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad ...
and FireWire. USB requires the presence of a host controller, typically a PC, which connects point to point with the USB device. This allows for simpler (and lower-cost) peripherals, at the cost of lowered functionality of the bus. Intelligent hubs are required to connect multiple USB devices to a single USB host controller. By contrast, FireWire is essentially a peer-to-peer network
Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network. They are said to form a peer-to-peer n ...
(where any device may serve as the host or client), allowing multiple devices to be connected on one bus.
The FireWire host interface supports DMA and memory-mapped devices, allowing data transfers to happen without loading the host CPU with interrupts and buffer-copy operations. Additionally, FireWire features two data buses for each segment of the bus network, whereas, until USB 3.0, USB featured only one. This means that FireWire can have communication in both directions at the same time (full-duplex), whereas USB communication prior to 3.0 can only occur in one direction at any one time (half-duplex).
While USB 2.0 expanded into the fully backwards-compatible USB 3.0
USB 3.0, released in November 2008, is the third major version of the Universal Serial Bus (USB) standard for interfacing computers and electronic devices. Among other improvements, USB 3.0 adds the new transfer rate referred to as '' ...
and 3.1 (using the same main connector type), FireWire used a different connector between 400 and 800 implementations.
Common applications
Consumer automobiles
IDB-1394 Customer Convenience Port (CCP) was the automotive version of the 1394 standard.
Consumer audio and video
IEEE 1394 was the High-Definition Audio-Video Network Alliance
The High-Definition Audio-Video Network Alliance (HANA) was a cross-industry collaboration of members addressing the end-to-end needs of connected, HD, home entertainment products and services. Leading companies formed the organization from the fo ...
(HANA) standard connection interface for A/V (audio/visual) component communication and control. HANA was dissolved in September 2009 and the ''1394 Trade Association'' assumed control of all HANA-generated intellectual property.
Military and aerospace vehicles
SAE Aerospace standard AS5643 originally released in 2004 and reaffirmed in 2013 establishes IEEE-1394 standards as a military and aerospace databus network in those vehicles. AS5643 is utilized by several large programs, including the F-35 Lightning II
The Lockheed Martin F-35 Lightning II is an American family of single-seat, single-engine, all-weather stealth multirole combat aircraft that is intended to perform both air superiority and strike missions. It is also able to provide elect ...
, the X-47B UCAV aircraft, AGM-154
The AGM-154 Joint Standoff Weapon (JSOW) is a glide bomb that resulted from a joint venture between the United States Navy and Air Force to deploy a standardized medium range precision guided weapon, especially for engagement of defended targets ...
weapon and JPSS-1
NOAA-20, designated JPSS-1 prior to launch, is the first of the United States National Oceanic and Atmospheric Administration's latest generation of U.S. polar-orbiting, non-geosynchronous, environmental satellites called the Joint Polar Sate ...
polar satellite for NOAA. AS5643 combines existing 1394-2008 features like looped topology with additional features like transformer isolation and time synchronization, to create deterministic double and triple fault-tolerant data bus networks.
General networking
FireWire can be used for ad hoc (terminals only, no routers except where a FireWire hub is used) computer network
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ...
s. Specifically, RFC 2734 specifies how to run IPv4 over the FireWire interface, and RFC 3146 specifies how to run IPv6
Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet. IPv ...
.
Mac OS X, Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, w ...
, and FreeBSD include support for networking over FireWire. Windows 95
Windows 95 is a consumer-oriented operating system developed by Microsoft as part of its Windows 9x family of operating systems. The first operating system in the 9x family, it is the successor to Windows 3.1x, and was released to manufacturi ...
, Windows 98
Windows 98 is a consumer-oriented operating system developed by Microsoft as part of its Windows 9x family of Microsoft Windows operating systems. The second operating system in the 9x line, it is the successor to Windows 95, and was released to ...
, Windows Me
Windows Millennium Edition, or Windows Me (marketed with the pronunciation of the pronoun "me"), is an operating system developed by Microsoft as part of its Windows 9x family of Microsoft Windows operating systems. It is the successor to Windo ...
, Windows XP
Windows XP is a major release of Microsoft's Windows NT operating system. It was released to manufacturing on August 24, 2001, and later to retail on October 25, 2001. It is a direct upgrade to its predecessors, Windows 2000 for high-end and ...
and Windows Server 2003
Windows Server 2003 is the sixth version of Windows Server operating system produced by Microsoft. It is part of the Windows NT family of operating systems and was released to manufacturing on March 28, 2003 and generally available on April 24, 2 ...
include native support for IEEE 1394 networking. Windows 2000
Windows 2000 is a major release of the Windows NT operating system developed by Microsoft and oriented towards businesses. It was the direct successor to Windows NT 4.0, and was released to manufacturing on December 15, 1999, and was officiall ...
does not have native support but may work with third party drivers. A network can be set up between two computers using a single standard FireWire cable, or by multiple computers through use of a hub. This is similar to Ethernet
Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1 ...
networks with the major differences being transfer speed, conductor length, and the fact that standard FireWire cables can be used for point-to-point communication.
On December 4, 2004, Microsoft announced that it would discontinue support for IP networking over the FireWire interface in all future versions of Microsoft Windows. Consequently, support for this feature is absent from Windows Vista
Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...
and later Windows releases.
Microsoft rewrote their 1394 driver in Windows 7
Windows 7 is a major release of the Windows NT operating system developed by Microsoft. It was released to manufacturing on July 22, 2009, and became generally available on October 22, 2009. It is the successor to Windows Vista, released nearly ...
but networking support for FireWire is not present. Unibrain offers free FireWire networking drivers for Windows called ubCore, which support Windows Vista and later versions.
Some models of the PlayStation 2 console had an i.LINK-branded 1394 connector. This was used for networking until the release of an Ethernet adapter late in the console's lifespan, but very few software titles supported the feature.
IIDC
IIDC (Instrumentation & Industrial Digital Camera) is the FireWire data format standard for live video, and is used by Apple's iSight
iSight is a brand name used by Apple Inc. to refer to cameras on various devices. The name was originally used for the external iSight webcam, which retailed for US$149, connected to a computer via a FireWire cable, and came with a set of mou ...
A/V camera. The system was designed for machine vision
Machine vision (MV) is the technology and methods used to provide imaging-based automatic inspection and analysis for such applications as automatic inspection, process control, and robot guidance, usually in industry. Machine vision refers to ...
systems but is also used for other computer vision applications and for some webcams. Although they are easily confused since they both run over FireWire, IIDC is different from, and incompatible with, the ubiquitous AV/C (Audio Video Control) used to control camcorders and other consumer video devices.
DV
Digital Video ( DV) is a standard protocol
Protocol may refer to:
Sociology and politics
* Protocol (politics), a formal agreement between nation states
* Protocol (diplomacy), the etiquette of diplomacy and affairs of state
* Etiquette, a code of personal behavior
Science and technolog ...
used by some digital camcorder
A camcorder is a self-contained portable electronic device with video and recording as its primary function. It is typically equipped with an articulating screen mounted on the left side, a belt to facilitate holding on the right side, hot-swa ...
s. All DV cameras that recorded to tape media had a FireWire interface (usually a 4-conductor). All DV ports on camcorders only operate at the slower 100 Mbit/s speed of FireWire. This presents operational issues if the camcorder is daisy chained from a faster S400 device or via a common hub because any segment of a FireWire network cannot support multiple speed communication.
Labeling of the port varied by manufacturer, with Sony using either its i.LINK trademark or the letters ''DV''. Many digital video recorders have a ''DV-input'' FireWire connector (usually an alpha connector) that can be used to record video directly from a DV camcorder (computer-free). The protocol also accommodates remote control (play, rewind, etc.) of connected devices, and can stream time code from a camera.
USB is unsuitable for the transfer of the video data from tape because tape by its very nature does not support variable data rates. USB relies heavily on processor support and this was not guaranteed to service the USB port in time. The later move away from tape towards solid-state memory or disc media (e.g., SD Cards, optical disks or hard drives) has facilitated moving to USB transfer because file-based data can be moved in segments as required.
Frame grabbers
IEEE 1394 interface is commonly found in frame grabber
A frame grabber is an electronic device that captures (i.e., "grabs") individual, digital still frames from an analog video signal or a digital video stream. It is usually employed as a component of a computer vision system, in which video fram ...
s, devices that capture and digitize an analog video signal; however, IEEE 1394 is facing competition from the Gigabit Ethernet
In computer networking, Gigabit Ethernet (GbE or 1 GigE) is the term applied to transmitting Ethernet frames at a rate of a gigabit per second. The most popular variant, 1000BASE-T, is defined by the IEEE 802.3ab standard. It came into use ...
interface (citing speed and availability issues).
iPod and iPhone synchronization and charging
iPods released prior to the iPod with Dock Connector used IEEE 1394a ports for syncing music and charging, but in 2003, the FireWire port in iPods was succeeded by Apple's dock connector
A dock connector is a connector used to attach a mobile electronic device simultaneously to multiple external resources. The dock connector will typically carry a variety of signals and power, through a single connector, to simplify the process o ...
and IEEE 1394 to 30-pin connector cables were made. Apple Inc.
Apple Inc. is an American multinational technology company headquartered in Cupertino, California, United States. Apple is the largest technology company by revenue (totaling in 2021) and, as of June 2022, is the world's biggest company ...
dropped support for FireWire cables starting with iPod nano (4th Generation), iPod touch (2nd Generation)
The second-generation iPod Touch (marketed as "the new iPod touch", and colloquially known as the iPod Touch 2G, iPod Touch 2, or iPod 2) is a multi-touch mobile device designed and marketed by Apple Inc. with a touchscreen-based user interfac ...
, and iPhone in favor of USB
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad ...
cables.
Security issues
Devices on a FireWire bus can communicate by direct memory access
Direct memory access (DMA) is a feature of computer systems and allows certain hardware subsystems to access main system memory independently of the central processing unit (CPU).
Without DMA, when the CPU is using programmed input/output, it is ...
(DMA), where a device can use hardware to map internal memory to FireWire's ''physical memory space''. The SBP-2 (Serial Bus Protocol 2
The Serial Bus Protocol 2 (SBP-2) standard is a transport protocol within the Serial Bus, IEEE Std 1394-1995 (also known as FireWire or i.Link), developed by T10.
Original work on Serial Bus Protocol started as an attempt to adapt SCSI to IEEE ...
) used by FireWire disk drives uses this capability to minimize interrupts and buffer copies. In SBP-2, the initiator (controlling device) sends a request by remotely writing a command into a specified area of the target's FireWire address space. This command usually includes buffer addresses in the initiator's FireWire ''Physical Address Space'', which the target is supposed to use for moving I/O data to and from the initiator.
On many implementations, particularly those like PCs and Macs using the popular OHCI
A host controller interface (HCI) is a register-level interface that enables a host controller for USB or IEEE 1394 hardware to communicate with a host controller driver in software. The driver software is typically provided with an operating sys ...
, the mapping between the FireWire ''physical memory space'' and device physical memory is done in hardware, without operating system intervention. While this enables high-speed and low-latency communication between data sources and sinks without unnecessary copying (such as between a video camera and a software video recording application, or between a disk drive and the application buffers), this can also be a security or media rights-restriction risk if untrustworthy devices are attached to the bus and initiate a DMA attack
A DMA attack is a type of side channel attack in computer security, in which an attacker can penetrate a computer or other device, by exploiting the presence of high-speed expansion ports that permit direct memory access (DMA).
DMA is included in ...
. One of the applications known to exploit this to gain unauthorized access to running Windows, Mac OS and Linux computers is the spyware FinFireWire
FinFisher, also known as FinSpy, is surveillance software marketed by Lench IT Solutions plc, which markets the spyware through law enforcement channels.
FinFisher can be covertly installed on targets' computers by exploiting security lapses in t ...
. For this reason, high-security installations typically either use newer machines that map a virtual memory
In computing, virtual memory, or virtual storage is a memory management technique that provides an "idealized abstraction of the storage resources that are actually available on a given machine" which "creates the illusion to users of a very ...
space to the FireWire ''physical memory space'' (such as a Power Mac G5
The Power Mac G5 is a series of personal computers designed, manufactured, and sold by Apple Computer, Inc. from 2003 to 2006 as part of the Power Mac series. When introduced, it was the most powerful computer in Apple's Macintosh lineup, and ...
, or any Sun workstation
The SUN workstation was a modular computer system designed at Stanford University in the early 1980s. It became the seed technology for many commercial products, including the original workstations from Sun Microsystems.
History
In 1979 Xerox do ...
), disable relevant drivers at operating system level, disable the OHCI hardware mapping between FireWire and device memory, physically disable the entire FireWire interface, or opt to not use FireWire or other hardware like PCMCIA, PC Card, ExpressCard or Thunderbolt
A thunderbolt or lightning bolt is a symbolic representation of lightning when accompanied by a loud thunderclap. In Indo-European mythology, the thunderbolt was identified with the 'Sky Father'; this association is also found in later Hel ...
, which expose DMA to external components.
An unsecured FireWire interface can be used to debug a machine whose operating system has crashed, and in some systems for remote-console operations. Windows natively supports this scenario of kernel debugging, although newer Windows Insider
Windows Insider is an open software testing program by Microsoft that allows users globally who own a valid license of Windows 11, Windows 10, or Windows Server to register for pre-release builds of the operating system previously only accessible ...
Preview builds no longer include the ability out of the box. On FreeBSD, the dcons driver provides both, using gdb
The GNU Debugger (GDB) is a portable debugger that runs on many Unix-like systems and works for many programming languages, including Ada, C, C++, Objective-C, Free Pascal, Fortran, Go, and partially others.
History
GDB was first written by ...
as debugger. Under Linux, firescope and fireproxy exist.
See also
*DMA attack
A DMA attack is a type of side channel attack in computer security, in which an attacker can penetrate a computer or other device, by exploiting the presence of high-speed expansion ports that permit direct memory access (DMA).
DMA is included in ...
*HAVi Havi may refer to:
*''Hávi'', a variant form of '' Hár'', one of the names of Odin, the chief god in Norse mythology
* HAVi, the Home Audio Video Interoperability standard
{{disambiguation ...
* Linux IEEE 1394 target
* List of interface bit rates
* Pin control attack
References
Further reading
*
*
*
External links
*
*
IEEE 1394 connectors pinout
{{DEFAULTSORT:Ieee 1394 Interface
Computer buses
Computer connectors
Computer storage buses
IEEE standards
Macintosh internals
Personal area networks
Serial buses
Television terminology
Video signal