1、BRITISH STANDARD BS IEC 796-3:1990 Implementation of IEC796-3:1990 Microprocessor system BUS I,8-bit and16-bit data Part3: Mechanical and pin descriptions for the Eurocard configuration with pin and socket(indirect) connectorsBSIEC796-3:1990 This British Standard, having been prepared under the dire
2、ctionof the Information Systems Technology Standards Policy Committee, was publishedunder the authority ofthe Standards Board and comesinto effect on 28February1991 BSI 04-2000 The following BSI references relate to the work on this standard: Committee reference IST/6 Draft for comment 90/65490 DC I
3、SBN 0 580 19341 1 Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted by the Information Systems Technology Standards Policy Committee(IST/-) to Technical Committee IST/6, upon which the following bodies were represented: Association for Payment Clea
4、ring Services British Computer Society British Telecommunications plc Business Equipment and Information Technology Association Department of Trade and Industry (Information Technology Standards Unit) Department of Trade and Industry (National Physical Laboratory) Electronic Engineering Association
5、Electricity Supply Industry in England and Wales HM Treasury(Central Computer and Telecommunications Agency) Information Technology Users Standards Association Institute of Data Processing Management Inter-Universities Computing Committee Joint Network Team National Computing Centre Ltd. National He
6、alth Service OFTEL (Office of Telecommunications) Post Office Telecommunications Engineering and Manufacturing Association Telecommunications Managers Association Amendments issued since publication Amd. No. Date CommentsBSIEC796-3:1990 BSI 04-2000 i Contents Page Committees responsible Inside front
7、 cover National foreword ii Foreword iii Text of IEC796-3 1BSIEC796-3:1990 ii BSI 04-2000 National foreword This BritishStandard reproduces verbatim IEC796-3 and implements it as the UK national standard. This British Standard is published under the direction of the Information Systems Technology St
8、andards Policy Committee whose Technical Committee IST/6 has the responsibility to: aid enquirers to understand the text; present to the responsible international committee any enquiries on interpretation, or proposals for change, and keep UK interests informed; monitor related international and Eur
9、opean developments and promulgate them in the UK. For the purposes of this BritishStandard, any references to page numbers in the text should be ignored. NOTEInternational and European Standards, as well as overseas standards, are available from BSI Sales Department, BSI, Linford Wood, Milton Keynes
10、, MK146LE. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document
11、 comprises a front cover, an inside front cover, pages i and ii, theIEC title page, pages ii to iv, pages1 to5 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BSIEC
12、796-3:1990 ii BSI 04-2000 Contents Page Foreword iii Introduction 1 1 Scope 1 2 Object 1 3 Definitions 1 3.1 Backplane 1 3.1.1 Front of a backplane 1 3.2 Eurocard 1 3.2.1 Front of a Eurocard 1 3.2.2 Rear edge of a Eurocard 1 4 Eurocard connectors 1 5 Eurocards 1 5.1 Eurocard construction techniques
13、1 5.2 Reference designations and pin numbering standards 1 5.3 Eurocard dimensions 1 5.4 Eurocard non-bus edge connectors 2 5.5 Component side 2 5.6 Board to board relationships 2 5.6.1 Board to board spacing 2 5.6.2 Board thickness 2 5.6.3 Component height 2 5.6.4 Clearance of the card guide edges
14、2 5.7 Backplane 2 5.8 Bus pin assignment 2 Figure 2 Double size Eurocard 3 Figure 3 Eurocard reference designation 3 Figure 4 Single size Eurocard 4 Table I Eurocard bus connector P1 (96-pin IEC603-2 Connector) 5BSIEC796-3:1990 BSI 04-2000 iii Foreword 1) The formal decisions or agreements of the IE
15、C on technical matters, prepared by Technical Committees on which all the National Committees having a special interest therein are represented, express, as nearly as possible, an international consensus of opinion on the subjects dealt with. 2) They have the form of recommendations for internationa
16、l use and they are accepted by the National Committees in that sense. 3) In order to promote international unification, the IEC expresses the wish that all National Committees should adopt the text of the IEC recommendation for their national rules in so far as national conditions will permit. Any d
17、ivergence between the IEC recommendation and the corresponding national rules should, as far as possible, be clearly indicated in the latter. 4) The IEC has not laid down any procedure concerning marking as an indication of approval and has no responsibility when an item of equipment is declared to
18、comply with one of its recommendations. Preface This standard has been prepared by Sub-Committee47B 1) : Microprocessor systems, of IEC Technical Committee No.47: Semiconductor devices. This standard forms Part3 of a series of publications, the other parts being: The text of this standard is based o
19、n the following documents: Full information on the voting for the approval of this standard can be found in the Voting Report indicated in the above table. The following IEC publication is quoted in this standard: 1) IEC Sub-Committee47B has now been transferred to ISO/IEC JTC1. This standard was ap
20、proved according to IEC procedures and is therefore published as an IEC standard. Publication796-1:1990: Part1: Functional description with electrical and timing specifications. Publication796-2:1990: Part2: Mechanical and pin descriptions for the system bus configuration, with edge connectors (dire
21、ct). Six Months Rule Report on Voting 47B(CO)10 47B(CO)14 Publication No130-14:1975: Connectors for frequencies below3MHz, Part14: Multi-row board mounted printed board connectors having contact and termination spacing on a2.54mm(0.1in) square grid. (Thispublication has been withdrawn from sale.)iv
22、blankBSIEC796-3:1990 BSI 04-2000 1 Introduction This standard is one of a series which deals with the electrical and mechanical interfaces to allow various microprocessor system components to interact with each other. The interface bus serves as a parallel transfer and utility signal interconnect fo
23、r closely coupled system components. The series consists of one functional description and two alternative mechanical standards. 1 Scope This standard is applicable to an interface used to connect microprocessor system components by means of the pin and socket(indirect) connector type backplane. 2 O
24、bject The object of this standard is to provide information to assure that bus backplanes, card racks and printed circuit boards are mechanically compatible. 3 Definitions The following definitions apply for the purpose of this standard: 3.1 backplane A board into which96-pin connectors are installe
25、d. This board interconnects some of the pins of these connectors to provide a bus. 3.1.1 front of a backplane the front of a backplane is the side from which the Eurocards are inserted in the connectors 3.2 Eurocard A printed circuit board which is plugged into the backplane and communicates with ot
26、her Eurocards installed in the same backplane. 3.2.1 front of a Eurocard the front of a Eurocard is the side on which the components are mounted 3.2.2 rear edge of a Eurocard the rear edge of a Eurocard is the edge which provides the onboard connector for mating with the connector on the backplane 4
27、 Eurocard connectors Eurocards require a96-pin IEC603-2 connector, in accordance with IEC Publication130-14, on the top rear edge of the Eurocard which is identified as P1. If a connector exists on the bottom rear edge of the Eurocard, it is designated as P2 and should be an IEC standard connector.
28、The height of the components on the front of each Eurocard shall not exceed15.3mm(0.6in). The female connector is attached to the backplane, the male connector is attached to the module. 5 Eurocards This clause provides the following Eurocard information: a) construction techniques; b) reference des
29、ignations and pin numbering standards; c) overall dimensions; d) connector information. 5.1 Eurocard construction techniques Many construction techniques are available to the designer. To provide optimum power and ground distribution, a multilayer printed circuit design is recommended; however, this
30、 is not a requirement for bus compatibility. If a multilayer printed circuit design is not used (i.e., no ground plane is provided), care should be taken to assure that an adequate ground grid is provided on the board. 5.2 Reference designations and pin numbering standards Refer to Figure1. The foll
31、owing standard is recommended for identification purposes (doublesize Eurocard): Connectors on the back edge of the Eurocard are designated P1 and P2. P1 is the96-pin primary connector, and P2 is an optional secondary connector. Refer to Figure 3, page3. 5.3 Eurocard dimensions Figure 2, page3, illu
32、strates a double size Eurocard. Figure 4, page 4, illustrates the single size Eurocard dimensions. These dimensions enable a designer to manufacture a board that mates with only the96-pin bus backplane socket. Unless the free edge is supported, it is not recommended that this size of a board be used
33、 in a card cage with double size boards.BSIEC796-3:1990 2 BSI 04-2000 5.4 Eurocard non-bus edge connectors It is recommended for ease of access and stability that all boards requiringI/O utilize the optional J1 (and J2) connectors for I/O. This is not a requirement for bus compatibility. 5.5 Compone
34、nt side Eurocard printed circuit boards shall be inserted into a card rack from the front of the system (seeSub-clause3.1.1) in a vertical position with the P1 connector at the top of the rear edge. Looking to the backplane from the front of the system the components shall be on the right side of th
35、e inserted printed circuit boards. 5.6 Board to board relationships The following printed circuit board specifications shall be adhered to when designing boards compatible with this standard. 5.6.1 Board to board spacing Center to center of boards when plugged into the backplane shall be at least20m
36、m(0.79in). 5.6.2 Board thickness The typical board thickness is1.6mm(0.063in). 5.6.3 Component height The component on a printed circuit board shall not exceed14mm (0.55in) in height above the component side. The component leads shall not extend more than2.54mm(0.1in) from the solder side. 5.6.4 Cle
37、arance of the card guide edges Solder fillets, tracking and components shall be a minimum of2.54mm(0.1in) from the edges of the board to guarantee clearance between them and the card guides. 5.7 Backplane The primary backplane is designated as P1 backplane. In many cases this is the only backplane i
38、n the system. When a double high rack is used, this backplane is mounted in the upper position. The use of female96-pin IEC603-2 connectors on the backplane is mandatory. 5.8 Bus pin assignment Printed circuit boards interface the system bus by the P1 connector. Table I shows the pin signal assignme
39、nt for the P1 connector.BSIEC796-3:1990 BSI 04-2000 3 All dimensions are in millimetres with inches provided in parentheses for reference only. The millimetre dimensions govern. Figure 2 Double size Eurocard Figure 3 Eurocard reference designationBSIEC796-3:1990 4 BSI 04-2000 All dimensions are in m
40、illimetres with inches provided in parentheses for reference only. The millimetre dimensions govern. Figure 4 Single size EurocardBSIEC796-3:1990 BSI 04-2000 5 Table I Eurocard bus connector P1 (96-PIN IEC603-2 Connector) Connector pin a b c 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 2
41、3 24 25 26 27 28 29 30 31 32 MRDC* MWTC* BPRN* BPRO* Not bussed Reserved (bussed) INT0* INT3* INT6* Not bussed +5V +5V Reserved for serial link(bussed) +5V +5V A0* A3* A5* A8* A11* A13* A16* A19* A21* A23* LOCK* D0* D3* D6* D8* D11* D14* BCLK* GND BUSY* CBRQ* Not bussed GND INT1* INT4* GND XACK* Not
42、 bussed +12V GND 12V INH1* A1* GND A6* A9* GND A14* A17* GND A22* BHEN* GND D1* D4* GND D9* D12* GND IORC* IOWC* INTA* BREQ* Not bussed Reserved (bussed) INT2* INT5* INT7* INIT* Not bussed +12V Reserved for serial link (bussed) 12V INH2* A2* A4* A7* A10* A12* A15* A18* A20* +5V +5V CCLK* D2* D5* D7*
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