SIST EN 60958-4:2004
(Main)Digital audio interface -- Part 4: Professional applications
Digital audio interface -- Part 4: Professional applications
The interface specified in this standard is primarily intended to carry monophonic or stereophonic programmes at a 48 kHz sampling frequency and with a resolution of up to 24 bits per sample. It may alternatively be used to carry signals sampled at other rates such as 32 kHz, 44,1 kHz, or 96 kHz.
Digitalton-Schnittstelle -- Teil 4: Professioneller Gebrauch
Interface audionumérique -- Partie 4: Applications professionnelles
La CEI 60958-4:2003 spécifie une application professionnelle de l'interface pour l'interconnexion des appareils audionumériques définie dans la CEI 60958-1. La présente version bilingue (2013-05) correspond à la version anglaise monolingue publiée en 2003-05.
Digitalni avdio vmesnik – 4. del: Profesionalna uporaba (IEC 60958-4:2003)
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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Digitalni avdio vmesnik – 4. del: Profesionalna uporaba (IEC 60958-4:2003)Digitalton-Schnittstelle -- Teil 4: Professioneller GebrauchInterface audionumérique -- Partie 4: Applications professionnellesDigital audio interface -- Part 4: Professional applications35.200Vmesniška in povezovalna opremaInterface and interconnection equipment33.160.30Avdio sistemiAudio systemsICS:Ta slovenski standard je istoveten z:EN 60958-4:2003SIST EN 60958-4:2004en01-september-2004SIST EN 60958-4:2004SLOVENSKI
STANDARDSIST EN 60958-4:20011DGRPHãþD
SIST EN 60958-4:2004
SIST EN 60958-4:2004
SIST EN 60958-4:2004
SIST EN 60958-4:2004
SIST EN 60958-4:2004
INTERNATIONALSTANDARDIEC60958-4Second edition2003-05Digital audio interface –Part 4:Professional applications (TA4)Interface audionumérique –Partie 4:Applications professionnelles (TA4)© IEC 2003
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Copyright - all rights reservedNo part of this publication may be reproduced or utilized in any form or by any means, electronic ormechanical, including photocopying and microfilm, without permission in writing from the publisher.International Electrotechnical Commission,
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Telefax: +41 22 919 03 00
E-mail: inmail@iec.ch
Web: www.iec.chSFor price, see current cataloguePRICE CODECommission Electrotechnique InternationaleInternational Electrotechnical CommissionSIST EN 60958-4:2004
– 2 –60958-4 © IEC:2003(E)CONTENTSFOREWORD.3INTRODUCTION.51Scope.62Normative references.63Terms and definitions.64Interface format.64.1General.64.2Validity bit.65Channel status.75.1General.75.2Professional linear PCM application.76User data.156.1General.156.2Application.157Implementation.157.1General.157.2Transmitter.157.3Receivers.168Electrical requirements.168.1General.168.2Balanced line.16Bibliography.21Figure 1 – Simplified example of the configuration of the circuit (balanced).17Figure 2 – Intrinsic jitter measurement filter.18Figure 3 – Jitter attenuation mask (optional).18Figure 4 – Eye diagram.19Figure 5 – A suggested equalizing characteristic for the receiver operating at a framerate of 48 kHz.19Figure 6 – Receiver jitter tolerance template.20Table 1 – Channel status data format for professional linear PCM application.8SIST EN 60958-4:2004
60958-4 ¤ IEC:2003(E)– 3 –INTERNATIONAL ELECTROTECHNICAL COMMISSION____________DIGITAL AUDIO INTERFACE –Part 4: Professional applicationsFOREWORD1)The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprisingall national electrotechnical committees (IEC National Committees). The object of the IEC is to promoteinternational co-operation on all questions concerning standardization in the electrical and electronic fields. Tothis end and in addition to other activities, the IEC publishes International Standards. Their preparation isentrusted to technical committees; any IEC National Committee interested in the subject dealt with mayparticipate in this preparatory work. International, governmental and non-governmental organizations liaisingwith the IEC also participate in this preparation. The IEC collaborates closely with the International Organizationfor Standardization (ISO) in accordance with conditions determined by agreement between the twoorganizations.2)The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, aninternational consensus of opinion on the relevant subjects since each technical committee has representationfrom all interested National Committees.3)The documents produced have the form of recommendations for international use and are published in the formof standards, technical specifications, technical reports or guides and they are accepted by the NationalCommittees in that sense.4)
In order to promote international unification, IEC National Committees undertake to apply IEC InternationalStandards transparently to the maximum extent possible in their national and regional standards. Anydivergence between the IEC Standard and the corresponding national or regional standard shall be clearlyindicated in the latter.5)
The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for anyequipment declared to be in conformity with one of its standards.6)
Attention is drawn to the possibility that some of the elements of this International Standard may be the subjectof patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.International Standard IEC 60958-4 has been prepared by IEC technical committee 100: Audio,video and multimedia systems and equipment.This second edition of IEC 60958-4 cancels and replaces the first edition published in 1999 andconstitutes a technical revision.The text of this standard is based on the following documents:FDISReport on voting100/643/FDIS100/669/RVDFull information on the voting for the approval of this standard can be found in the report onvoting indicated in the above table.This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.The main changes with respect to the previous edition (1999) are listed below.−The scope specifies the professional application of IEC 60958-1 (generalities have beenremoved to an introduction).−A clause on terms and definitions has been added.−In Table 1, expanded channel status assignments have been added and channel statusdefinitions expanded to accommodate extended sampling frequencies, indication ofalignment level and multi-channel options.SIST EN 60958-4:2004
– 4 –60958-4 © IEC:2003(E)− Figure 1 and associated text has been revised to be more generalized. Three notes on cableperformance factors have been added.−The impedance specification is now dependent on maximum frame rate.−
The common-mode balance specification is now dependent on maximum frame rate−The impedance specification is now dependent on maximum frame rate.IEC 60958 consists of the following parts under the generic title Digital audio interface:Part 1:
GeneralPart 3:
Consumer applicationsPart 4:
Professional applicationsThe committee has decided that this publication remains valid until September 2005. At thisdate, in accordance with the committee’s decision, the publication will be•reconfirmed;•withdrawn;•replaced by a revised edition, or•amended.SIST EN 60958-4:2004
60958-4 ¤ IEC:2003(E)– 5 –INTRODUCTIONThe interface specified in this standard is primarily intended to carry monophonic orstereophonic programmes at a 48 kHz sampling frequency and with a resolution of up to 24 bitsper sample. It may alternatively be used to carry signals sampled at other rates such as32 kHz, 44,1 kHz, or 96 kHz. Note that conformity to this interface specification does notrequire equipment to utilize these rates and also that the capability of the interface toindicate other sample rates does not imply that it is recommended that equipment supportsthese rates. To eliminate doubt, equipment specifications should define the supported samplingfrequencies.The format is intended for use with shielded twisted-pair cables over distances of up to 100 mwithout transmission equalization or any special equalization at the receiver and at frame ratesof up to 50 kHz. Longer cable lengths and higher frame rates may be used with cables bettermatched for data transmission, or with receiver equalization, or both.In both cases, the clock references and auxiliary information are transmitted along with theaudio data. Provision is also made to allow the interface to carry non-audio data.SIST EN 60958-4:2004
– 6 –60958-4 © IEC:2003(E)DIGITAL AUDIO INTERFACE –Part 4: Professional applications1 ScopeThis International Standard specifies the professional application of the interface for theinterconnection of digital audio equipment defined in IEC 60958-1.2 Normative referencesThe following referenced documents are indispensable for the application of this document. Fordated references, only the edition cited applies. For undated references, the latest edition ofthe referenced document (including any amendments) applies.IEC 60268-12:1987, Sound system equipment – Part 12: Application of connectors forbroadcast and similar useIEC 60958-1, Digital audio interface – Part 1: GeneralIEC 60958-3, Digital audio interface – Part 3: Consumer applicationsISO/IEC 646:1991, Information technology – ISO 7-bit coded character set for informationinterchangeITU-T Recommendation J.17:1988, Pre-emphasis used on sound-programme circuitsITU-T Recommendation V.11:1996, Electrical characteristics for balanced double-current inter-change circuits operating at data signalling rates up to 10 Mbit/s3 Terms and definitionsThe terms and definitions given in IEC 60958-1 apply to this part of IEC 60958.4 Interface format4.1 GeneralThe interface format as defined in IEC 60958-1 shall be used.For historical reasons, preambles “B”, “M” and “W”, as defined in 4.3 of IEC 60958-1, shall, foruse in professional applications, be referred to as “Z”, “X” and “Y”, respectively.4.2 Validity bitFor this standard, the validity bit shall be used to indicate whether the main data field bits in thesub-frame are suitable for conversion to an analogue audio signal using linear PCM coding.SIST EN 60958-4:2004
60958-4 ¤ IEC:2003(E)– 7 –5 Channel status5.1 GeneralThe channel status for each audio signal carries information associated with that audio signal;thus it is possible for different channel status data to be carried in the two sub-frames of thedigital audio signal. Examples of information to be carried in the channel status are: length ofaudio sample words, number of audio channels, sampling frequency, sample address code,alphanumeric source and destination codes, and pre-emphasis.Channel status information is organized in a 192-bit block, subdivided into 24 bytes, numbered0 to 23 (see Table 1). The first bit of each block is carried in the frame with preamble “Z”.The individual bits of a block are numbered 0 to 191.The primary application is indicated by channel status bit 0.For the professional applications described here, this first channel status bit equals “1”.NOTE
For consumer digital audio equipment, this first channel status bit equals “0”, and this part of IEC 60958does not apply.Secondary applications may be defined within the framework of these primary applications.5.2 Professional linear PCM applicationThe specific organization of the channel status data is defined in this clause and summarizedin Table 1.The significance of byte 0, bit 0 is such that a transmission from an interface conforming toIEC 60958-3 (“consumer use”) can be identified. Also, a “professional use” transmission,defined in this part of IEC 60958, can be correctly identified by a “consumer use” receiver.Connection of a “consumer use” transmitter with a “professional use” receiver or vice versamight result in unpredictable operation. Thus, the byte definitions in this clause apply only whenbit 0 = “1” and bit 1 = “0” (professional linear PCM use of the channel status block).SIST EN 60958-4:2004
– 8 –60958-4 © IEC:2003(E)Table 1 – Channel status data format for professional linear PCM applicationByte0a = “1”b = “0”CdeBit012345671fgBit891011121314152hijBit16171819202122233kn=”0”lmn=”1”Bit24252627282930314opqrBit32333435363738395Reserved but undefined at presentBit40414243444546476Alphanumeric channel origin dataBit48495051525354557Alphanumeric channel origin dataBit56575859606162638Alphanumeric channel origin dataBit64656667686970719Alphanumeric channel origin dataBit727374757677787910Alphanumeric channel destination databit808182838485868711Alphanumeric channel destination databit888990919293949512Alphanumeric channel destination databit9697989910010110210313Alphanumeric channel destination databit10410510610710810911011114Local sample address code (32-bit binary)bit11211311411511611711811915Local sample address code (32-bit binary)bit12012112212312412512612716Local sample address code (32-bit binary)bit12812913013113213313413517Local sample address code (32-bit binary)bit13613713813914014114214318Time of day code (32-bit binary)bit14414514614714814915015119Time of day code (32-bit binary)bit15215315415515615715815920Time of day code (32-bit binary)bit16016116216316416516616721Time of day code (32-bit binary)bit16816917017117217317417522Reliability flagsbit17617717817918018118218323Cyclic redundancy check characterbit184185186187188189190191a:use of channel status blockb:linear PCM identificationc:audio signal pre-emphasisd:lock indicatione:sampling frequencyf:channel modeg:user bits managementh:use of auxiliary sample bitsi:source word lengthj:indication of alignment levelk:channel numberl:channel numberm:multichannel mode numbern:multichannel modeo:digital audio reference signalp:reserved but undefined at presentq:sampling frequencyr:sampling frequency scaling flagSIST EN 60958-4:2004
60958-4 ¤ IEC:2003(E)– 9 –Byte 0Bit 0Use of channel status blockState“1”Professional use of channel status block (note 1)Bit 1Linear PCM identificationState“0”Audio sample word represents linear PCM samples (note 1)“1”Audio sample word used for purposes other thanlinear PCM samplesNOTE 1
The functions of channel status bits 0 and 1 are defined in IEC 60958-1.Bits 2 to 4Encoded audio signal pre-emphasis.Bit
2 3 4State“0 0 0”Pre-emphasis not indicated. Receiver defaults to no pre-emphasis with manual override enabled.“1 0 0”No pre-emphasis. Receiver manual override is disabled.“1 1 0”50µs/15 µs pre-emphasis. Receiver manual overrideis disabled.“1 1 1”ITU-T Recommendation J.17 pre-emphasis (with 6,5 dBinsertion loss at 800 Hz). Receiver manual override isdisabled.All other states of bits 2 to 4 are reserved and shall not be useduntil further defined.Bit 5Lock indicationState“0”Default, lock condition not indicated.“1”Source sampling frequency unlocked.Bits 6 to 7Encoded sampling frequencyBit 6 7State“0 0”Sampling frequency not indicated. Receiver defaults to48 kHz and manual override or auto set is enabled.“0 1”48 kHz sampling frequency. Receiver manual overrideor auto set is disabled.“1 0”44,1 kHz sampling frequency. Receiver manual override orauto set is disabled.“1 1”32 kHz sampling frequency. Receiver manual override orauto set is disabled.NOTE 2
The indication of sampling frequency, or the use of one of the sampling frequencies that can be indicatedin this byte, is not a requirement for operation of the interface.
The 00 state of bits 6 to 7 may be used if thetransmitter does not support the indication of sampling frequency, if the sampling frequency is unknown, or if thesample frequency is not one of those that can be indicated in this byte.
In the latter case for some samplingfrequencies byte 4 may be used to indicate the correct value.NOTE 3
When bits 8 to 11 in byte 1 indicate single-channel double-sampling frequency mode, the samplingfrequency of the audio signal is twice that indicated by bits 6 to 7 in byte 0.SIST EN 60958-4:2004
– 10 –60958-4 © IEC:2003(E)Byte 1The six modes of transmission are signalled by setting bits 8 to 11 of byte 1 of channel status.•Two-channel mode:
In two-channel mode, the samples from both channels are transmittedin consecutive sub-frames. Channel 1 is in sub-frame 1 and channel 2 is in sub-frame 2.•Stereophonic mode:
In stereophonic mode, the interface is used to transmit stereophonicsignals, and the two channels are presumed to have been simultaneously sampled. Theleft, or “A”, channel is in sub-frame 1 and the right, or “B”, channel is in sub-frame 2.•Single-channel mode (monophonic):
In monophonic mode, the transmitted bit rate remainsat the normal two-channel rate and the audio sample word is placed in sub-frame 1.Time slots 4 to 31 of sub-frame 2 either carry the bits identical to sub-frame 1 or are set tological “0”. A receiver normally defaults to channel 1, unless manual override is provided.•Primary/secondary mode:
In some applications requiring two channels where one of thechannels is the main or primary channel while the other is a secondary channel, the primarychannel is in sub-frame 1 and the secondary channel is in sub-frame 2.•Multichannel mode:
The one or two channels carried on the interface are part of a largergroup. Channel identification within this group is in byte 3.•Single-channel double-sampling frequency mode:
Sub-frames 1 and 2 carry successivesamples of the same signal. The sampling frequency of the signal is double the framerepetition rate and is double the sampling frequency indicated in byte 0 (but not doublethe rate indicated in byte 4, if that is used). Manual override is disabled.Bits 8 to 11Encoded channel modeBit 8 9 10 11State“0 0 0 0”Mode not indicated. Receiver defaults to two-channelmode and manual override is enabled.“0 0 0 1”Two-channel mode. Receiver manual override isdisabled.“0 0 1 0”Single-channel mode (monophonic). Receiver manualoverride is disabled.“0 0 1 1”Primary/secondary mode (sub-frame 1 is primary).Receiver manual override is disabled.“0 1 0 0”Stereophonic mode (sub-frame 1 is left channel).Receiver manual override is disabled.“0 1 0 1” and“0 1 1 0”Reserved for user-defined applications.“0 1 1 1”Single-channel double-sampling frequency mode –vector t
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