ISO/IEC INTERNATIONAL STANDARD 9316 Second edition 1995-11-01 Information technology --- Small Computer System Interface-2 Technologies de I'information - InterfaceSmall Computer System-2w IEC (so Reference number ISO/IEC 9316:1995(E) Copyright Intermational Organization for Standardization rovided by IHS mitted without license from IHS Not for Resale ISO/IEC 9316:1995(E) Contents Page 1 Scope 1 2 Normative references 2 3 Definitions, symbols and abbreviations 3 3.1Definitions 3 3.2 Symbols and abbreviations 5 4General 6 4.1Overview 9 4.2Conventions 7 5 Physical characteristics 8 5.1 Physical description 8 5.2 Cable requirements 8 5.2.1 Single-ended cable 8 5.2.2 Differential cable 9 5.2.3 Cable requirements for fast synchronous data transfer 9 5.3Connectorrequirements 9 5.3.1 Non-shielded connector requirements 9 5.3.1.1 Non-shielded connector alternative 1 - A cable 9 5.3.1.2 Non-shielded connector alternative 2 - A cable 10 5.3.1.3 Non-shielded connector - B cable 10 5.3.2 Shielded connector requirements 15 5.3.2.1 Shielded connector alternative 1 -A cable 15 5.3.2.2 Shielded connector alternative 2 - A cable 15 5.3.2.3 Shielded connector - B cable 15 5.3.3Connectorcontactassignments 20 C ISO/IEC1995 All rights reserved.Unless otherwisespecified,no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, publisher. Printed in Switzerland ii No reproduction or networking permited witho Not for Resale ISO/IEC 9316:1995(E) CISO/IEC 5.4 Electrical description 25 5.4.1 Single-ended alternative 25 5.4.1.1 Output characteristics 25 5.4.1.2 Input characteristics 25 5.4.2 Differential alternative 26 5.4.2.1 Output characteristics 26 5.4.2.2 Input characteristics 26 5.4.3 Terminator power 26 5.4.4RESERVED lines 29 5.5 ScSI bus 30 5.6 ScSl bus signals 32 5.6.1 Signal values 33 5.6.2 OR-tied signals 33 5.6.3 Signal sources 33 5.7 SCSI bus timing 34 5.7.1 Arbitration delay 35 5.7.2 Assertion period 35 5.7.3 Bus clear delay 35 5.7.4 Bus free delay 35 5.7.5 Bus set delay 36 5.7.6 Bus settle delay 36 5.7.7Cableskewdelay 36 5.7.8 Data release delay 36 5.7.9 Deskew delay 36 5.7.10 Disconnection delay 36 5.7.11 Hold time 36 5.7.12 Negation period 36 5.7.13 Power-on to selection time 36 5.7.14Resettoselectiontime 36 5.7.15 Reset hold time 37 5.7.16 Selection abort time 37 5.7.17 Selection time-out delay 37 5.7.18 Transfer period 37 5.8 Fast synchronous transfer option 37 5.8.1 Fast assertion period 37 5.8.2 Fast cable skew delay 37 5.8.3 Fast deskew delay 37 5.8.4 Fast hold time 37 5.8.5 Fast negation period 38 6 Logical characteristics 39 6.1 ScsI bus phases 39 6.1.1BUSFREEphase 39 6.1.2 ARBITRATION phase 40 6.1.3 SELECTION phase. . 40 6.1.3.1 SELECTION time-out procedure 41 6.1.4 RESELECTION phase 41 6.1.4.1 RESELECTION 41 6.1.4.2 RESELECTION time-out procedure 42 6.1.5Informationtransferphases 42 6.1.5.1 Asynchronous information transfer 43 6.1.5.2 Synchronous data transfer 43 6.1.5.3 Wide data transfer 44 ili No reproduction or network ing permitted withc from IHS ISO/IEC 9316:1995(E) @ISO/EC 6.1.6 COMMAND phase 46 6.1.7 Data phase 46 6.1.7.1 DATA IN phase 46 6.1.7.2 DATA OUT phase 46 6.1.8 STATUS phase 46 6.1.9 Message phase 46 6.1.9.1 MESSAGE IN phase 46 6.1.9.2 MESSAGE OUT phase 46 6.1.10 Signal restrictions between phases 47 6.2 SCSI bus conditions 47 6.2.1 Attention condition 47 6.2.2 Reset condition 48 6.2.2.1 Hard reset alternative 49 6.2.2.2 Soft reset alternative 49 6.3 scsl bus phase sequences 50 6.4 SCSI pointers . . 51 6.5 Message system description 52 6.6 Messages . 55 6.6.1ABORT 55 6.6.2 ABORT TAG 55 6.6.3 BUS DEVICE RESET 56 6.6.4 CLEAR QUEUE 56 6.6.5 COMMAND COMPLETE 56 6.6.6 DISCONNECT 56 6.6.7 IDENTIFY 57 6.6.8IGNORE WIDE RESIDUE 58 6.6.9 INITIATE RECOVERY 58 6.6.10 INITIATOR DETECTED ERROR 59 6.6.11 LINKED COMMAND COMPLETE 59 6.6.12 LINKED COMMAND COMPLETE (WITH FLAG) 59 6.6.13 MESSAGE PARITY ERROR 59 6.6.14MESSAGEREJECT 59 6.6.15 MODiFY DATA POINTER Message 60 6.6.1