Target Mode Usage Scsi Protocol Handling | Ciprico Rimfire 3880

Chapter 8 Details of Usage

Target Mode Usage and SCSI Protocol Handling

Page 8 - 11

Target Mode

Usage and

SCSI Protocol

Handling

Writing a driver for Target Mode requires a strong familiarity with the SCSI protocol. This section explains what you can expect from the adapter under certain SCSI conditions. This section addresses the following issues:

•Selection Queue

•SCSI Bus Reset Handling

•Target Mode Disable Command Handling

•Abort Command Handling

•Synchronous Data Transfer Requests

•Wide Data Transfer Requests

•Unexpected Messages Received from the Initiator

•Automatic Adapter Responses

•Disconnects

•Message Handling

Selection Queue

In order to buffer SCSI bus activities from Host events, selection information (from initiators on the SCSI bus), destined for the Target Selection Data Structure, is queued on the adapter. Information from about sixty initiator selections can be stored in the Selection Queue. This means that at the time of a SCSI bus reset, or a Target Mode Disable or Abort command, the queue may have initiator selection information that has not yet been processed by the Host.

SCSI Bus

Reset

Handling

To avoid a timing window with the host, Target Mode will be terminated upon receipt of a SCSI bus reset. The host may then re-enable the Target Mode when it is ready to continue receiving commands from other initiators. During the time between a bus reset and being re-enabled, the adapter will respond to selection attempts with Busy status.

Upon reset of the SCSI bus, all targets must terminate all commands in process. The RF3880 will do the following:

•Clear the Selection Queue.

•Set the current Target Selection Data Structure Error field to 27H, and clear the TME bit in the Flags field.

•Return Status Blocks for all outstanding Target Mode Response commands with an Error Code of 27H.

At this time the Host should do the following:

•Discard all outstanding initiator selections.

•Process and discard Status Blocks from Target Mode Response commands.

•Re-enable Target Mode when all processes are cleared.

User’s Guide

21020285 D

Image 185

Ciprico Rimfire 3880 manual Target Mode Usage Scsi Protocol Handling, Selection Queue, Scsi Bus Reset Handling

Contents

Rimfire 3880 Scsi Host Bus Adapter Page Page 21020285 D User’s Guide Preface Organization Overview of the RF3880 User’s Guide Initiator Mode Pass-through Commands DescribesOrganization Notational Graphic ConventionsConventions Graphic Representation of Parameter Block 21020285 D Reference Documents Reference Documents Contents Scsi ID Status Block Format LUN LUN Table of Contents Description of Fields Command Identifier Diagnostic/Self-test 09H Table of Contents Table of Contents Introduction Summary Specifications Index O d u c t O v e r v i e w About Rimfire Design Latest Bus SpecificationsBuffering scheme Product Overview About the Rimfire 3880 Design Buffer Management Target Mode Implementation Product Overview What next? What next? R d w a r e E s s e n t i a l s Hardware Essentials Introduction IntroductionSummary Intel 80186XL Hardware Structure DescriptionQLogic FAS Pipelined System Interface Data Buffer Generator blocks are part of the PSI Block DiagramHardware Essentials Choosing an Address Modifier Board AddressingChoosing a VMEbus Address Hardware Essentials Board Addressing Overview of the Ports Hardware Port AddressesHardware Essentials Hardware Ports General Hardware Port Addresses Hardware Essentials Hardware Ports General Hardware Essentials Address Buffer Port Address Buffer PortAddress Buffer Port Writes Address Modifier Field Control Field of Address Buffer Port Hardware Essentials Address Buffer Port Control Field Hardware Essentials Channel Attention Port Single Command Structure Address FieldsChannel Attention Port Channel Attention Channel Format Status Port Reset Status Port Reset FormatStatus Port Hardware Essentials Status Port Status Port Error Codes Status Port Error Codes Status Port General Status Port General Format Chapter Hardware Essentials Status Port Status Port Catastrophic Error Codes Hardware Essentials Reset Port Reset Port Hardware Essentials Descriptions of Port Usage Descriptions of Port Usage Hardware Essentials R d w a r e Installation Hardware Installation Introduction Overview Installation Process Shipping Damage Unpacking the Board Hardware Installation Unpacking the BoardStep Unpacking Board Step Jumpers Termination Hardware Installation Jumpers and Termination Default Jumper Settings Configuration Jumpers Bus Request/Grant and Sysfail Jumpers Bus Request/ Grant Jumper Jumper Sysfail Example Example Base Address Jumper SettingsAddresses For the Address Modifier Jumper Scsi bus Termination Replacement Fuse General Steps Hardware Installation Board Insertion Meaning LED’s Power-up SequenceHardware Installation Apply power and observe LEDs Error Conditions Hardware Installation Configure and Connect Scsi Devices Step Configure Connect Scsi DevicesSelectable Options Options Cabling Scsi Cable Connector Hardware Installation M m a n d O p e r a t i o n Command Operation Introduction What the Adapter must accomplish Command Operation What the Adapter must accomplish Parameter BaseBlock Parameter Command Descriptor Block Base Status Block Command Operation Base Status BlockStatus Block Format Base Status Block Command Operation Base Status Block Multiple Status Blocks Setting up Unit Options Format Single Command Structure Single Command StructureCommand Operation Single Command Structure Parameter Block Bit-meanings of Interrupt Field Command Operation Single Command Structure Interrupt Command Operation Using a Single Command Structure Using a Single Command Structure Example Start Command List Board-control Some Example Single CommandsCommand Operation Some Example Single Commands Command Identifier = 822F4H Interrupt = 0300H Command = 01H 21020285 D User’s Guide Example Pass-through command PB Example 2Inquiry Pass-through Command Command Operation Command Operation Some Example Single Commands Description of the Fields Command List StructureFormat Command List Structure Number of Status Blocks Number of Parameter BlocksParameter Block Space Status Block Space Command Operation Creating the Command List Structure Creating Command List Structure Command Guidelines Using a Command List StructureCommand Operation Using a Command List Structure Index Guidelines Adding a Parameter Block Removing a Status Block Command Operation Example ‘C’ Routines for Command List Example ‘C’ Routines for Command List Stcdone Command Operation Example ‘C’ Routines for Command List Command Operation I t i a t o r t h r o u g h D e P a s s C o m m a n d s Introduction Summary Initiator Mode Pass-through Commands Introduction Initiator Pass- through Parameter Block Format Command FormatTarget ID Address Modifier Bit-meanings of Flags-1 Field DIR and DAT Settings, Vendor-unique Setting DBV DAT and DIR Bits Using Table ValuesExample DAT and DIR bit settings DAT and DIR Automatic Settings Table of DAT DIR Automatic Settings 4EH Initiator Mode Pass-through Commands Meaning of TAG Opts Bits Flags-2Bit-meanings of Flag-2 Field Transfer Count Scsi Command Descriptor BlockVME Memory Address Message Code Message FormatPass-through Message Parameter Block Bit-meanings of Flags Field Description of FieldsScsi Pass-through Status Block Error Meaning of Status Byte Code Scsi Status Field during Unexpected Scsi PhaseBit-meanings of Scsi Status Field Meaning of Status Byte Unexpected Phase Three signals. This is described below Ordering of 1st 16 Sequential Sense Bytes Default Ordering of Sense BytesUp to 32 Sequential Sense Bytes Example of Selected Sense Bytes Initiator Mode Pass-through Commands R g e t t h r o u g h D e P a s s C o m m a n d s Target Mode Pass-through Commands Introduction Target Mode Pass-through Commands Overview of Target Mode What is Target Mode? What must the adapter accomplish in Target Mode? Target Mode Pass-through CommandsAdapter must have a means of handling Scsi protocol issues New commands Overview Special Target Mode CommandsTarget Mode Enable Command Target Mode Disable Command Scsi Command Descriptor Block Groups Command Descriptor Block Group Codes Target Mode Pass-through Commands Command Operation Command OperationSequence Events Enabling Target Mode Sequence Events Receiving a Command From an Initiator Sequence of Events Responding to an Initiator Target Selection Data Structure Target Selection Data Structure Meaning of Flags Field Meaning of Scsi Flags Field Identify Message Received Command Descriptor Block LengthInitiator Identifier Message Bytes Received Semaphore Field Initiator ID Target Mode Response CommandTarget Mode Response Parameter Block ⇒ Target Mode Response command Meaning of Response Control Flags Field Status or 1st Message Byte Message Byte Second TM Response Command Status Block Target Mode Response Command Status BlockFirst TM Response Command Status Block Meaning of Status Block Flags Field Meaning of Command Status Flags Field Message Byte Received Target Mode Error Sequence Codes A r d c o n t r o l C o m m a n d s Board-control Commands Introduction Board-control Commands Using the Reference Using the Reference General Status Block Board-control Commands General Status BlockGeneral Status Block Format General Status Block Board-control Commands List of CommandsBoard-control Commands List of Commands Start Command List Parameter Block Board-control Commands Start Command List 01HCommand List Memory Address Adapter ID Command Code Board-control Commands Start Command List 01H Interrupt Stop Command List Parameter Block Board-control Commands Stop Command List 02H Identify 05H Board-control Commands Identify 05HIdentify Command Parameter Block Identify Command Status Block Identify Command Status BlockEngineering Revision Firmware Revision Option Flags Field Identify Status Block Board-control Commands Identify 05H Option FlagsAdapter Scsi ID Bits Day, Month, Year Board Statistics 06H Board-control Commands Board Statistics 06HBoard Statistics Command Parameter Block Options Field Board-control Commands Board Statistics 06H Options Total Scsi Commands issued to an ID Total Commands ProcessedTarget Mode Selection Count Statistics Data Structure Board-control Commands General Options 07H Command Format Description of FieldsGeneral Options Command Parameter Block General Options 07H Bus Throttle Field Values Bus ThrottleSelect Flags Select Flags Byte Command code for this command is 07H Unit Options Command Parameter Block Board-control Commands Unit Options 08HUnit Options 08H Unit Scsi ID Retry Limit Board-control Commands Unit Options 08H Disconnect Time-outRetry Control Retry Control Unit Flags Select Time-outUnit Flags Sense Count Initiator Mode Selected Sense Bytes Example Selection of Sense Bytes Example Use of Selected Sense Bytes Fields Board-control Commands Diagnostic/Self-test 09H Diagnostic/ Self-test 09HDiagnostic/Self-test Parameter Block Diagnostics Command Test Flags Field Command code for this operation is 09H Bit-meanings of Flags Byte in Status Block Diagnostic Command Status BlockFlags Byte Board-control Commands Target Mode Enable 0AH Target Mode Enable 0AHTarget Mode Enable Parameter Block Pointer to the Target Selection Data Structure Meaning of Selection Interrupt Field Board-control Commands Target Mode Disable 0BH Target Mode Disable 0BHTarget Mode Disable Parameter Block Meaning of Flags-1 Field Command Identifier of CMD to be Aborted Board-control Commands Abort 0DHAbort 0DH Abort Parameter Block Scsi Hard Reset Parameter Block Scsi Hard Reset 10HBoard-control Commands Scsi Hard Reset 10H Board Information 15H Board-control Commands Board Information 15H Board Information Data Structure Board-control Commands Board Information 15H OptionsBoard Information Options Field Board Information Data Structure Board Information Select Flags Field Board-control Commands Board Information 15H Bus Throttle RST Reset Jumper Board-control Commands Board Information 15H Option Flags Adapter Base Model # Board-control Commands Board Information 15H TerminationScsi Cfig Block Per Target Sense Count Per Target Retry LimitPer Target Device Flags Bit-meanings of Device Flags Field Per Target Synch Period Per Target Selected Sense Bytes Per Target Width Extended Board Statistics Parameter Block Board-control Commands Extended Board Statistics 16HExtended Board Statistics 16H Extended Board Options Field Board-control Commands Extended Board Statistics 16H Options Number of Scsi Parity Errors Total Commands IssuedPer Scsi Target Number of Commands Extended Statistics Data Structure Per Scsi Target Maximum Queued Board-control CommandsPer Scsi Target Queue Full Count Extended Unit Options Parameter Block Board-control Commands Extended Unit Options 18HExtended Unit Options 18H Extended Unit Options Data Structure Extended Unit Options Data Structure Description of Fields Bit-meanings of Retry Control Field Unit Flags of Extended Unit Options Board-control Commands Extended Unit Options 18H Unit Flags Board-control Commands Extended Unit Options 18H Selected Sense Bytes T a i l s o f U s a g e Details of Usage Introduction Details of Usage Byte and Word Swapping Need for SwappingExample of Memory Differences Variations in Intel and Motorola Memory Pass-through command Parameters Motorola Ordering Intel Ordering Intel Ordered Parameter Block Command Structure SwappingRF3880 Swapping Options Dual Initiators Data SwappingSharing Tapes Tagged How to UseQueuing Tagged RF3880 sends the tag message Details of Usage Tagged Queuing Choose a tag messageMeaning of Flags-2 Field Queue Tag Numbers UsageQueue Full Status Message Reject Selection Queue Target Mode Usage Scsi Protocol HandlingScsi Bus Reset Handling Abort Command Handling Synchronous Data Transfer Requests Target Mode Disable Command Handling Wide Data Transfer Requests Message parity errors Parity error conditionsInitiator-detected Error messages Target Routines Message Bytes Received from the Initiator Disconnect PrivilegeMessage Handling 21020285 D User’s Guide User’s Guide 21020285 D Details of Usage Error codes Codes Reported in Status Block and Status Port Status Block Error CodesAppendix a Error Codes Introduction Error Codes Appendix a Error Codes Summary 2BH Appendix a Error Codes A1H Appendix a Error Codes Status Port Error Codes Status Port Error CodesCatastrophic Error Codes Self-test Error Codes Diagnostic Command 8CH Self-test Status Port Error Codes B l e s a n d C o n n e c t o r s Appendix B Cables and Connectors Introduction Appendix B Cables and Connectors Scsi Connector ConnectorCable Connector Pin-outs for the RF3886 Maximum Cable Length P1 Connector VMEbus Connector PinoutsAppendix B Cables and Connectors VMEbus Connector Pinouts Retry P2 Connector Appendix B Cables and Connectors Specification s Appendix C Specifications Introduction Specifications for the Rf3880 SpecificationsAppendix C Specifications Appendix C Specifications 21020285 D User’s Guide Fault s Appendix D Defaults Introduction Appendix D Defaults Hardware Defaults Hardware DefaultsHardware Defaults Jumpers Defaults for Hardware Ports Command Defaults DefaultsAppendix D Defaults TAG Appendix D Defaults S i g n D i f f e r e n c e s Appendix E Design Differences Introduction Appendix E Design Differences Features no longer Supported Features no longer SupportedScatter/Gather Operations Byte and Word Swapping of Data Appendix E Design Differences Implementation Differences Status Port Error Codes and Test FlagsWidth of Data Transfers on the VMEbus Extended Scsi ID’s Scsi Data Widths Block Mode Transfers Odd-byte Addressing How to Maximize Performance D e Index User’s Guide 21020285 D PSI Scsi ID Index Page 21020285 D