BS-IEC-796-3-1990.pdf

BRITISH STANDARD BS IEC 796-3:1990 Implementation of IEC 796-3:1990 Microprocessor system BUS I, 8-bit and 16-bit data Part 3: Mechanical and pin descriptions for the Eurocard configuration with pin and socket (indirect) connectors Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 796-3:1990 This British Standard, having been prepared under the direction of the Information Systems Technology Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 28 February 1991 © BSI 04-2000 The following BSI references relate to the work on this standard: Committee reference IST/6 Draft for comment 90/65490 DC ISBN 0 580 19341 1 Committees responsible for this British Standard The preparation of this British Standard 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 Clearing 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 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 Health Service OFTEL (Office of Telecommunications) Post Office Telecommunications Engineering and Manufacturing Association Telecommunications Managers Association Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 796-3:1990 © BSI 04-2000i Contents Page Committees responsibleInside front cover National forewordii Forewordiii Text of IEC 796-31 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 796-3:1990 ii © BSI 04-2000 National foreword This British Standard reproduces verbatim IEC 796-3 and implements it as the UK national standard. This British Standard is published under the direction of the Information Systems Technology Standards 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 European developments and promulgate them in the UK. For the purposes of this British Standard, 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, MK14 6LE. 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 comprises a front cover, an inside front cover, pages i and ii, the IEC title page, pages ii to iv, pages 1 to 5 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. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 796-3:1990 ii © BSI 04-2000 Contents Page Forewordiii Introduction1 1Scope1 2Object1 3Definitions1 3.1Backplane1 3.1.1Front of a backplane1 3.2Eurocard1 3.2.1Front of a Eurocard1 3.2.2Rear edge of a Eurocard1 4Eurocard connectors1 5Eurocards1 5.1Eurocard construction techniques1 5.2Reference designations and pin numbering standards1 5.3Eurocard dimensions1 5.4Eurocard non-bus edge connectors2 5.5Component side2 5.6Board to board relationships2 5.6.1Board to board spacing2 5.6.2Board thickness2 5.6.3Component height2 5.6.4Clearance of the card guide edges2 5.7Backplane2 5.8Bus pin assignment2 Figure 2 Double size Eurocard3 Figure 3 Eurocard reference designation3 Figure 4 Single size Eurocard4 Table I Eurocard bus connector P1 (96-pin IEC 603-2 Connector)5 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 796-3:1990 © BSI 04-2000iii Foreword 1) The formal decisions or agreements of the IEC 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 international 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 divergence 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 comply with one of its recommendations. Preface This standard has been prepared by Sub-Committee 47B1): Microprocessor systems, of IEC Technical Committee No. 47: Semiconductor devices. This standard forms Part 3 of a series of publications, the other parts being: The text of this standard is based on 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-Committee 47B has now been transferred to ISO/IEC JTC 1. This standard was approved according to IEC procedures and is therefore published as an IEC standard. Publication 796-1:1990:Part 1: Functional description with electrical and timing specifications. Publication 796-2:1990:Part 2: Mechanical and pin descriptions for the system bus configuration, with edge connectors (direct). Six Months RuleReport on Voting 47B(CO)1047B(CO)14 Publication No 130-14:1975: Connectors for frequencies below 3 MHz, Part 14: Multi-row board mounted printed board connectors having contact and termination spacing on a 2.54 mm (0.1 in) square grid. (This publication has been withdrawn from sale.) Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 796-3:1990 © BSI 04-20001 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 for 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 Object 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 which 96-pin connectors are installed. 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 other 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 Eurocard connectors Eurocards require a 96-pin IEC 603-2 connector, in accordance with IEC Publication 130-14, 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. The height of the components on the front of each Eurocard shall not exceed 15.3 mm (0.6 in). 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 designations 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 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 Figure 1. The following standard is recommended for identification purposes (double size Eurocard): Connectors on the back edge of the Eurocard are designated P1 and P2. P1 is the 96-pin primary connector, and P2 is an optional secondary connector. Refer to Figure 3, page 3. 5.3 Eurocard dimensions Figure 2, page 3, illustrates 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 the 96-pin bus backplane socket. Unless the free edge is supported, it is not recommended that this size of a board be used in a card cage with double size boards. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 796-3:1990 2 © BSI 04-2000 5.4 Eurocard non-bus edge connectors It is recommended for ease of access and stability that all boards requiring I/O utilize the optional J1 (and J2) connectors for I/O. This is not a requirement for bus compatibility. 5.5 Component side Eurocard printed circuit boards shall be inserted into a card rack from the front of the system (see Sub-clause 3.1.1) 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 the 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 least 20 mm (0.79 in). 5.6.2 Board thickness The typical board thickness is 1.6 mm (0.063 in). 5.6.3 Component height The component on a printed circuit board shall not exceed 14 mm (0.55 in) in height above the component side. The component leads shall not extend more than 2.54 mm (0.1 in) from the solder side. 5.6.4 Clearance of the card guide edges Solder fillets, tracking and components shall be a minimum of 2.54 mm (0.1 in) 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 in the system. When a double high rack is used, this backplane is mounted in the upper position. The use of female 96-pin IEC 603-2 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 assignment for the P1 connector. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 796-3:1990 © BSI 04-20003 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 designation Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 796-3:1990 4 © BSI 04-2000 All dimensions are in millimetres with inches provided in parentheses for reference only. The millimetre dimensions govern. Figure 4 Single size Eurocard Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 796-3:1990 © BSI 04-20005 Table I Eurocard bus connector P1 (96-PIN IEC 603-2 Connector) Connector pinabc 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 MRDC* MWTC* BPRN* BPRO* Not bussed Reserved (bussed) INT 0* INT 3* INT 6* Not bussed + 5 V + 5 V Reserved for serial link (bussed) + 5 V + 5 V A0* A3* A5* A8* A11* A13* A16* A19* A21* A23* LOCK* D0* D3* D6* D8* D11* D14* BCLK* GND BUSY* CBRQ* Not bussed GND INT 1* INT 4* GND XACK* Not bussed + 12 V GND 12 V INH 1* 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) INT 2* INT 5* INT 7* INIT* Not bussed + 12 V Reserved for serial link (bussed) 12 V INH 2* A2* A4* A7* A10* A12* A15* A18* A20* + 5 V + 5 V CCLK* D2* D5* D7* D10* D13* D15* Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 796-3:1990 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions British Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel: 020 8996 9000. Fax: 020 8996 7400. BSI offers members an individual updating service called PLUS