TRA Vol. I • No.

7 • July, 1996
®
Presented by the Corporation of America
Editor: Michael G. D’Amore
Special IEEE 1394 Issue! Associate Editor: Howard Massey
Production by: On the Right Wavelength
A Glimpse Into The Digital Future .... page 2 Send correspondence via e-mail
to news@ysba.com or
The Yamaha AMP Proposal................ page 6 mgdamore@ysba.com or,
via “snail-mail,” to:
The MMA Studies IEEE 1394..... ........ page 11
XG Xtra
Yamaha Corporation of America
Office of Strategic Business Development
Visit our WorldWide Web site at: P. O. Box 6600
http://www.ysba.com Buena Park, CA 90620
Tel: 714-522-9330
 IEEE 1394:
A Glimpse Into The Digital Future
developers face a the MIDI to the SMPTE, and the 1394 is designed to work with pretty
XG bewildering array of
interconnect options—
RS232 to the RS422...”), this has to
sound like a dream come true.
much every kind of electronic gear
imaginable, including (but not
MIDI connections, gamestick port Well, the dream is very nearly reality, limited to):
configurations, various types of hard thanks to a grouping of four digits
drives and CD-ROM interfaces, and you’re going to be seeing a lot of in • Computers, both desktop and
the like. But imagine a world in the months ahead: 1394. That’s the portable
which all of these devices—in fact, number assigned by the IEEE
every high-tech device you own— (Institute of Electrical and • Consumer electronics products
can be interconnected with one Electronic Engineers) to designate a such as set-top boxes, VCRs,
single cable, using one single hardware and software standard for a camcorders, and digital TVs
protocol. If you’ve spent far too high-performance serial bus which
many frustrating hours swimming in many believe will one day become • Multimedia products such as
interface alphabet soup (“OK, now the universal interface we’ve all digital cameras and stereo/audio
let’s connect the SCSI to the IDE, dreamed of. equipment

XG Xtra Vol. I Number 7 Page 2

 • Electronic publishing products A company called Skipstone Why is 1394 gaining such immense
such as printers and scanners (http://www.skipstone.com/) has support amongst manufacturers
taken a leading role in providing worldwide? The answer lies in its
• Data storage and retrieval developer toolkits for implementing phenomenal feature set. 1394 is:
products such as hard disk drives 1394 capability. They predict that, by
and CD-ROMs 1997, a wide range of consumer • Fast - 100 and 200 Mbps data
electronics and computer manufac- rates are available today, with
1394’s genesis lay in the “FireWire” turers will offer hardware matched 400 Mbps and 1 Gbps slated in
technology originally developed by by the inclusion of 1394 into the near future. This allows
Apple Computer as a desktop LAN. popular operating systems. Microsoft real-time data transfer for
Quickly recognizing its potential in has already announced support of multimedia applications,
many other applications, the IEEE 1394 in future releases of the including digital audio and
soon formed both a study group and Windows® family of operating video.
a trade association. The 1394 Trade systems and has signed letters of
Association (http://firewire.org/) intent with Sony (to develop open • Reliable - 1394’s isochronous data
includes Yamaha as a charter device driver interfaces [DDIs], APIs transport format (a protocol with
member, along with industry and an open host controller interface a continuous guaranteed
heavyweights Sony, Intel, Microsoft, for 1394) and with Compaq bandwidth data stream) ensures
Apple, Texas Instruments and many (to accelerate adoption of 1394 as a delivery of multiple time-critical
others. Sony’s recent release of a line standard in the PC industry, multimedia data for real-time
of 1394-equipped Digital Video including defining an open host applications.
HandyCams represents the first controller interface specification).
consumer products to utilize this By 1998, gigabit/second 1394 devices • Backward compatible - 1394’s
technology. are expected to be on the market. isochronous mechanism operates

XG Xtra Vol. I Number 7 Page 3

 transparently on top of a • Easy to use - Attaching a 1394 • Physically small - The thin serial
standard asynchronous data device is as easy as plugging a cable used by 1394 can replace
transport format (the cord into an electrical outlet. larger and more expensive
conventional transmit- Automatic configuration interfaces.
acknowledgment protocol) in supports “plug and play,” and
order to provide connectivity to devices running at different • Flexible - Free-form network
legacy technology such as speeds can be mixed on the same topology allows daisy chaining
printers and modems as well as system, allowing backward and branching for true peer-to-
command and control for new compatibility with devices peer communication without
devices. And, even though 1394 having slower transport rates. consuming system memory and
is a serial interface, legacy I/O This feature also allows 100 Mbps CPU resources.
“bridges” allow the attachment devices purchased today to
of both serial and parallel operate properly in future bus • Non-proprietary - There is no
interfaces. configurations involving 200 and licensing required to use 1394 in
400 Mbps devices. Also, there are products.
• Inexpensive - 1394 is priced for no separate line terminators
consumer products, plus its required, and no need for device Little wonder that many are
guaranteed delivery of IDs. proclaiming 1394 as the future
time-critical data reduces costly “AC plug” of multimedia!
buffer requirements. In addition, • Hot pluggable - Users can add or
common connectors are used for remove 1394 devices without Yamaha is currently developing a
different devices and data loss or interruption while proposal for using 1394 for the
applications. the bus is active. interconnection of musical

XG Xtra Vol. I Number 7 Page 4

equipment (this proposal is possible migration of the MIDI pro- XG publications available
tentatively called the Audio and tocol. For more information about from Yamaha
Music Protocol, or “AMP” for short) AMP, see the article on page 6 of this
as well as participating in a study issue of XG Xtra, or click here.
committee formed by the MIDI For more on the MMA’s views about • XG Interactive Online Help
Manufacturers Association (MMA) to 1394, see the article on page 11 of • An Introduction to XG
consider the adoption of 1394 for this issue of XG Xtra, or click here. • XG Guidebook
• XG Music Production Recommendations
Click on these URLs for more information about IEEE 1394:
• XG Specifications
• 1394 Trade Association: • XG Voice List and Drum Map
http://firewire.org/ • XG Xtra issues #1 - #6

All available online (www.ysba.com) or

• Skipstone: in hard copy direct from Yamaha:
http://www.skipstone.com/ Send requests via e-mail to:
news@ysba.com
or, via “snail-mail,” to:
• Sony: XG Xtra
http://www.sel.sony.com/SEL/consumer/camcorder/ Yamaha Corporation of America
dcr_vx1000.html Office of Strategic Business Development
P. O. Box 6600
Buena Park, CA 90620
• Texas Instruments: Tel: 714-522-9330
http://www.ti.com/sc/docs/msp/1394/1394.htm Fax: 714-228-3913

XG Xtra Vol. I Number 7 Page 5

 The Yamaha Audio and Music Protocol
(AMP) Proposal
he IEEE is currently studying a
T proposal made by Yamaha to
incorporate within 1394 a
standardized protocol for the
interconnection of musical
devices—in effect, a kind of MIDI
for the future, but one which will
handle both music performance data
and digital audio data, both down
the same wire. As shown in figure 1,
the proposal begins by defining the
scope of an “mLAN” (musical Local
Area Network), in which these
time-critical data streams are
distributed amongst all the
components.

Figure 1

XG Xtra Vol. I Number 7 Page 6

In order to enable usage in live Each device in the mLAN may have then maintain the connection
performance environments, onboard up to 31 output plugs and/or up to information, such as which channel
connection management (both 31 input plugs, with each plug is used for the isochronous flow,
isochronous and asynchronous) referred to by an integer number which input plug receives the flow,
is utilized so that the various from 0 to 30. A connection is and which output plug sends the
instruments in the mLAN can regarded as a combination of an flow. Also, since the actual
maintain their connection without output plug that has a broadcast-out transmitter and receiver may not
the need for external devices such connection and an input plug that “know” each other, when a power
as a computer. This is accomplished has a broadcast-in connection. reset occurs, the application that
through both input and output In this type of “broadcast established the connection should
“plug managers” that monitor and connection,” multiple input plugs resume the connection.
control the data flow from both can be added without any
physical 1394 connectors and virtual modification to the output plug. When no computer is present to
plugs that may be seen by the provide such a concentrated
receiving instruments as carrying When an mLAN includes a connection management, a
legacy data (such as MIDI). The plug computer, software may be used to transmitter and a receiver should
managers’ efficiency must be such manage all the connections on the still be capable of managing the
that even a “worst case” scenario bus. This type of connection connection established on their
(i.e. maximum number of nodes, management is called “concentrated plugs. This environment is regarded
with all nodes asserting connection management.” An as “distributed connection
asynchronous packet transmission) application that wants to establish a management”. In distributed
will result in a latency time of no connection should set an output connection management, connec-
more than 6 milliseconds. plug and an input plug to enable tions are persistent across a power
sending or receiving of an reset or bus reset. This persistency is
isochronous flow, and should necessary because the concept of

XG Xtra Vol. I Number 7 Page 7

mLAN connection is an analogy of plug #2 of a node with a particular channel messages (which are time-
the actual cabling system of the Node_Unique_ID. A plug registration critical and must be available to
existing audio, MIDI, and power does not, however, cause an actual multiple devices) using the former
supply. Here, a plug manager is data flow. method and MIDI system messages
introduced so that each device can (which often require responses from
maintain and restore connection, After a bus reset, the output plug receiving devices) using the latter.
with each device submitting requests manager will resume the As always, the MIDI data stream can
to the plug manager to establish a transmission on the registered contain timing and control
connection. The transmitter is output plug, while the input plug information such as MTC
responsible for transmitting an manager will check if the source of (MIDI Time Code) and MMC
isochronous stream on a specified the incoming flow is identical to the (MIDI Machine Control). Buffers
isochronous flow, while receivers are registered input plug. The are used to ensure real-time
responsible for receiving the registration will be non-volatile for transmission and response.
isochronous flow from the specified the connection restoration so that,
transmitter. after a power reset, although the Digital audio data, on the other
isochronous flow is not resumed, the hand, will utilize bidirectional
Registration of either end point of a connection information maintained isochronous data transmission, as
connection is simply called “plug before the power reset remains. shown in figure 2 on the following
registration.” For example, a page.
registration might inform the output Attribute lists are used to specify the
plug manager that output plug #5 capabilities and functions of each The mLAN will be able to handle raw
will be used for 2-channel raw audio device in the mLAN. Music audio data and AES/EBU
at a 44.1 kHz sampling rate, or might performance data will be transferred (professional) format audio—and
request that the input plug manager utilizing both isochronous and can distribute both simultaneously,
prepare to receive data from output asynchronous methods, with MIDI if required. Up to 64 channels of

XG Xtra Vol. I Number 7 Page 8

 variable bit-length (up to 128 bits)
and variable sampling rate (up to
128 kHz) audio can be transmitted
over a single cable. Provision is also
made for timing conversion, sample
rate conversion and drift/jitter
compensation. As shown in figure 3
(on the next page), both the audio
data and sampling clock will be
transmitted simultaneously over the
one bus through the use of an
embedded time stamp that carries
word clock in order to synchronize
the transmitter and receiver.

Direct word clock I/O will also be

available at every node within the
mLAN, as shown in figure 4 on the
next page.
Figure 2
(text continues on page 11)

XG Xtra Vol. I Number 7 Page 9

Figure 3

Figure 4

XG Xtra Vol. I Number 7 Page 10

(Yamaha AMP, continued from page 9)
As with the original MIDI
specification, there is plenty of room
The MMA
in the AMP proposal for future
expansion. Subunit ID addresses are
used to access specific video
Studies
functionality such as that found in
digital VCRs and digital TV tuners.
And several of these addresses are IEEE 1394
reserved for future use—these may
define functionality we may not
have even thought of yet! This will
enable the future integration of digi-
T he 1996 Winter NAMM show
may have had relatively little in
the way of major new product
appoint a committee (which
includes representatives
Yamaha, Mackie, IBM, Roland,
from

announcements, but there sure was Microsoft and Ensoniq) to study the
tal video signal—and other kinds of
plenty going on behind the scenes. IEEE 1394 specification for possible
digital signals, perhaps not even yet
Perhaps the most significant event migration of the MIDI protocol.
defined—along with the digital
was a presentation made at the The committee will be responsible
audio and music performance (MIDI)
annual MMA meeting by Gary for proposing the basic requirements
data that the mLAN is distributing.
Hoffman of Skipstone, giving many and recommending a course of
For those of you who want to get members their first look at the power action for further study and progress.
into the real technical nuts and bolts of IEEE 1394 and piquing interest in XG Xtra spoke with Tom White,
of mLAN, the complete current AMP the possibility of actually using it to President and CEO of the MMA, and
proposal is posted on our Web site launch the next generation of MIDI. with David Oren, chairman of the
(http://www.ysba.com)—click here Shortly thereafter, the MMA MMA’s 1394 Steering Committee, to
to download it. Executive Board made a decision to get their views on the subject.

XG Xtra Vol. I Number 7 Page 11

Although it is the job of the their length and where they are committee is currently studying
committee to evaluate 1394 fully, it’s stored (in sound card ROM, for Yamaha’s AMP proposal (described
fair to say that both White and Oren example, or on a hard disk). on page 6 of this issue of XG Xtra)
are already strong proponents. 1394 has the potential to and hopes to have a ‘recommended
“I think it’s an excellent idea, for dramatically change the whole practice’ document regarding 1394
several different reasons,” White paradigm of working with audio.” published by the fall of 1996.
states, “the most significant of which Oren adds, “1394 appears to be a
is that it can serve to end the specification that will carry us well Oren points out the inroads 1394 has
segmentation of the marketplace. into the next century. There is a made in the consumer industry
For example, there are, for all strong feeling of consensus in the already, observing that digital video
practical purposes, currently several industry, a feeling of wanting to is really the enabling technology.
kinds of MIDI, from low-end GM move forward, and everyone I’ve “1394 has already been announced
applications to high-end uses such as talked to is very positive about the as the digital I/O standard for DVC
sample dump. There are also future it points to.” (Digital Video Cassette) and
currently two kinds of music data— indications are that it will probably
MIDI, which contains performance The main objective of the Steering also be the I/O standard for DVD,
information, and digital audio, Committee chaired by Oren is to which is going to be launched in a
which contains data describing the generate awareness of 1394 among big way in the coming year.” He
sounds themselves. One of the best MMA members and to then work adds, “Because there are several
things about 1394 is that it will allow towards defining what the migration different companies gearing up to
both kinds of data to converge into path will be from MIDI to 1394. produce 1394 chips, 1394 won’t
one, so that we’ll simply have music “1394 appears to allow all we had have the single-supplier problem
data, period. After all, if you think previously discussed for a newer, that led to the VHS vs. Beta wars.”
about it, the only difference between ‘high-speed’ MIDI, and a whole lot Both Oren and White also see 1394
MIDI and digital audio sounds is more,” he says. The steering as being inevitable: “The thing is,”

XG Xtra Vol. I Number 7 Page 12

says White, “it will happen in the expanded upon. “Logjam has been a the consumer market, providing, as
computer and consumer electronics problem up until now in certain it does, a single-connector solution
industries, whether we’re there or circumstances, but 1394 will not for creating a simple in-home
not—future devices will have 1394 only pretty much eliminate that, it network that is nonetheless
ports and future operating systems will allow us to add all the things to enormously powerful.”
will support the protocol. We have MIDI that people have been asking
a golden opportunity here to bring about for years—more channels, It is perhaps for developers of
MIDI into the mainstream.” greater resolution, more controller interactive multimedia content that
“Unofficially,” summarizes Oren, numbers, a greatly extended system White sees the greatest rewards:
“1394 is already a fait accompli.” exclusive command set, new kinds of “It used to be that computers had no
events, and so on.” Tied in with the audio, then there was some audio,
One of the most impressive statistics rise of higher-density storage devices but it’s always been kind of
given at the NAMM presentation was (such as DVD), this will not only give an afterthought,” he observes.
that a single 1394 cable operating at game developers much greater “1394 will allow us to do things with
the current rate of 200 Mbps (and control over audio content, but also audio we’ve never done before.
this is expected to rise to 1 Gbps by extend that control to the end user. It will, at long last, enable developers
1998) is capable of carrying the “Game developers will be able to tap to not only work with state-of-the-
content of 640 MIDI cables into a whole new set of tools for art audio, but to deliver it in a
(a staggering 10,240 channels of fashioning sounds, such as digital pristine form to end users.”
data) or 140 CD-quality audio mixing and customized DSP, and end
channels. This, of course, assumes users will also be able to For further information, contact the
the use of the current MIDI feature interactively alter the sounds in MMA at P.O. Box 3173, La Habra, CA
set at the current transmission rate, many new and exciting ways.” Oren 90632-3173 (phone 310-947-8689 or
but White is quick to point out that agrees, adding that “1394 would e-mail MMA@earthlink.net).
1394 will allow MIDI to be greatly appear to be the ideal medium for

XG Xtra Vol. I Number 7 Page 13