Buffer Management | Ciprico Rimfire 3880 specs

Chapter 1 Product Overview

About the Rimfire 3880 Design

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Buffer Management

It is in the buffer management technique employed by the RF3880 that the unique dedication to bandwidth applications is realized. The RF3880 hardware logic allows the buffer to be managed either as a large FIFO or as temporary storage of data from several commands.

The adapter dynamically adjusts the management of the buffer based on the type and size of the data transfers involved.

•For large block transfers (greater than 4 Kbytes) the adapter will setup the buffer like a FIFO. Both the SCSI and VME sides of the buffer are reserved for the transfers. In this mode, the hardware performs and manages the transfer, then signals completion. The advantage to this algorithm is that microprocessor involvement is minimal.

•On transfers of small data blocks, (less than or equal to 4 Kbytes) the adapter handles the buffer more like a cache. In this mode, each side of the buffer can act independently; data transfers can occur simultaneously, in response to separate commands. The advantage of this algorithm is that data is already in the buffer when it is ready to be processed—SCSI overhead is overlapped with data transfer on the VME side.

Target Mode Implementation

The RF3880 is unique in its implementation of Target Mode. When Target Mode is enabled, the adapter can act as an initiator and target on the SCSI bus. When operating as a target, the adapter passes SCSI command information to the Host. It is up to the Host to instruct the adapter what action to take. This provides an enormous flexibility for implementation.

User’s Guide

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Ciprico Rimfire 3880 manual Buffer Management, Target Mode Implementation

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 Graphic Representation of Parameter Block ConventionsNotational Graphic Conventions 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 Product Overview About the Rimfire 3880 Design Latest Bus SpecificationsAbout Rimfire Design Buffering scheme 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 Pipelined System Interface Data Buffer Hardware Structure DescriptionIntel 80186XL QLogic FAS Generator blocks are part of the PSI Block DiagramHardware Essentials Hardware Essentials Board Addressing Board AddressingChoosing an Address Modifier Choosing a VMEbus Address Hardware Port Addresses Hardware Port AddressesOverview of the Ports Hardware Essentials Hardware Ports General Hardware Essentials Hardware Ports General Address Modifier Field Address Buffer PortHardware Essentials Address Buffer Port Address Buffer Port Writes 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 Hardware Essentials Status Port Status Port Reset FormatStatus Port Reset 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 For the Address Modifier Jumper Example Base Address Jumper SettingsExample Addresses 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 Options Step Configure Connect Scsi DevicesHardware Installation Configure and Connect Scsi Devices Selectable 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 BaseParameter Block Command Descriptor Block Base Status Block Command Operation Base Status BlockBase Status Block Status Block Format Command Operation Base Status Block Multiple Status Blocks Setting up Unit Options Parameter Block Single Command StructureFormat Single Command Structure Command Operation Single Command Structure Bit-meanings of Interrupt Field Command Operation Single Command Structure Interrupt Command Operation Using a Single Command Structure Using a Single Command Structure Command Identifier = 822F4H Some Example Single CommandsExample Start Command List Board-control Command Operation Some Example Single Commands 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 Status Block Space Number of Parameter BlocksNumber of Status Blocks Parameter Block Space Command Operation Creating the Command List Structure Creating Command List Structure Index Guidelines Using a Command List StructureCommand Guidelines Command Operation Using a Command List Structure 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 Address Modifier Command FormatInitiator Pass- through Parameter Block Format Target ID 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 Target Mode Disable Command Overview Special Target Mode CommandsNew commands Target Mode Enable 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 Message Bytes Received Command Descriptor Block LengthIdentify Message Received Initiator Identifier 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 General Status Block Format Board-control Commands List of CommandsBoard-control Commands List of Commands Adapter ID Board-control Commands Start Command List 01HStart Command List Parameter Block Command List Memory Address 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 Firmware Revision Identify Command Status BlockIdentify Command Status Block Engineering Revision Day, Month, Year Board-control Commands Identify 05H Option FlagsOption Flags Field Identify Status Block Adapter Scsi ID Bits Board Statistics 06H Board-control Commands Board Statistics 06HBoard Statistics Command Parameter Block Options Field Board-control Commands Board Statistics 06H Options Statistics Data Structure Total Commands ProcessedTotal Scsi Commands issued to an ID Target Mode Selection Count General Options 07H Command Format Description of FieldsBoard-control Commands General Options 07H General Options Command Parameter Block Select Flags Byte Bus ThrottleBus Throttle Field Values Select Flags Command code for this command is 07H Unit Scsi ID Board-control Commands Unit Options 08HUnit Options Command Parameter Block Unit Options 08H Retry Control Board-control Commands Unit Options 08H Disconnect Time-outRetry Limit 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 Diagnostics Command Test Flags Field Diagnostic/ Self-test 09HBoard-control Commands Diagnostic/Self-test 09H Diagnostic/Self-test Parameter Block Command code for this operation is 09H Bit-meanings of Flags Byte in Status Block Diagnostic Command Status BlockFlags Byte Pointer to the Target Selection Data Structure Target Mode Enable 0AHBoard-control Commands Target Mode Enable 0AH Target Mode Enable Parameter Block Meaning of Selection Interrupt Field Meaning of Flags-1 Field Target Mode Disable 0BHBoard-control Commands Target Mode Disable 0BH Target Mode Disable Parameter Block Abort Parameter Block Board-control Commands Abort 0DHCommand Identifier of CMD to be Aborted Abort 0DH 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 Data Structure Board Information Options Field 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 Bit-meanings of Device Flags Field Per Target Retry LimitPer Target Sense Count Per Target Device Flags 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 Extended Statistics Data Structure Total Commands IssuedNumber of Scsi Parity Errors Per Scsi Target Number of Commands 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 Variations in Intel and Motorola Memory Need for SwappingDetails of Usage Byte and Word Swapping Example of Memory Differences 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 UseTagged Queuing RF3880 sends the tag message Details of Usage Tagged Queuing Choose a tag messageMeaning of Flags-2 Field Message Reject UsageQueue Tag Numbers Queue Full Status 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 Target Routines Parity error conditionsMessage parity errors Initiator-detected Error messages 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 Maximum Cable Length ConnectorAppendix B Cables and Connectors Scsi Connector Cable Connector Pin-outs for the RF3886 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 Defaults for Hardware Ports Hardware DefaultsAppendix D Defaults Hardware Defaults Hardware Defaults Jumpers 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 Byte and Word Swapping of Data Features no longer SupportedAppendix E Design Differences Features no longer Supported Scatter/Gather Operations Extended Scsi ID’s Status Port Error Codes and Test FlagsAppendix E Design Differences Implementation Differences Width of Data Transfers on the VMEbus 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