Unexpected Reselection phase | Seagate Ultra 320, Ultra 160 instruction

A task manager that detects an incorrect initiator connection shall abort all tasks for the initiator and the associ- ated logical unit and shall return CHECK CONDITION status for the task that caused the incorrect initiator con- nection. The sense key shall be set to Aborted Command and the additional sense code shall be set to Overlapped Commands Attempted with the additional sense code qualifier set to the value of the duplicate tag (see Section 4.4).

Note. An incorrect initiator connection may be indicative of a serious error and, if not detected, could result in a task operating with a wrong set of pointers. This is considered a catastrophic failure on the part of the initiator. Therefore, vendor-specific error recovery procedures may be required to guarantee the data integrity on the medium. The target may return additional sense data to aid in this error recovery proce- dure (e.g., sequential-access devices may return the residue of blocks remaining to be written or read at the time the second command was received).

5.6.4Unexpected RESELECTION phase

An unexpected RESELECTION phase occurs if a SCSI target port attempts to do a physical reconnect to a task for which a nexus does not exist. a SCSI initiator port should respond to an unexpected RESELECTION phase by sending an ABORT TASK message.

112	Parallel SCSI Interface Product Manual, Rev. A

Image 126

Seagate Ultra 320, Ultra 160 manual Unexpected Reselection phase

Contents

Parallel Scsi Interface Page Parallel Scsi Interface Page Revision status summary sheet Revision Date Writer/Engineer Parallel Scsi Interface Product Manual, Rev. a Table of Contents Parallel Scsi Interface Product Manual, Rev. a Logical characteristics Wide transfer Message system specification Miscellaneous Scsi bus characteristics Scsi commandsSPI information units Drive features List of Figures Xii Parallel Scsi Interface Product Manual, Rev. a How to use this interface manual Interface requirements Scope of Scsi standards General interface description Applicable standards Glossary Scsi client-server modelPage Page Page Page Page Page Keywords Physical interface characteristics Summary of Scsi messagesMessage Name Hex Code Number Scsi bus Scsi IDs and associated Scsi bus arbitration priorities Priority Scsi bus signals overview Pcrc signal usage requirements Scsi target usage of Pcrca SE signals Signal statesSignal values LVD signals OR-tied signals Voltage and current definitions Data bit P cable Data bit a cable I/O DB15-8 Scsi bus phase Signal sourcesSignal sources DB7-0 Timing Scsi bus timingScsi bus control timing values in nanoseconds Reference Type Value ns Unless Timing description Nanoseconds unless otherwise noted Scsi bus data and information phase ST timing valuesTiming values for negotiated transfer rate Timing values for negotiated transfer rate in nanosecondsPage ATN transmit setup time Min Receive Scsi bus data and information phase DT timing values Total transmitter error budget Receiver errors Fast-160 Fast-320 CommentsInterconnect and system margin Crosstalk time shift ATN transmit setup timeATN receive setup time ISI of data Bus set delay Bus clear delayBus free delay Bus settle delay PCRC receive setup time Flow control receive setup timeFlow control transmit setup time PCRC transmit setup time Power on to selection Data release delayPhysical disconnection delay QAS arbitration delay Receive internal hold time Receive internal setup timeReceive setup time Receive negation period Reset to selection Reset delayReset hold time Residual skew error Strobe offset tolerance System deskew delaySkew correction range System noise at launch Measurement points Clocking methods for data transfers LVD measurement points ST latching data vs. DT latching data Paced transfer on a Scsi bus DT synchronous transfer example Synchronous transfers Data transfer modesAsynchronous transfers Paced transfers Data group transfers ST Data phase parallel transfersDT Data phase parallel transfers Information unit transfers Negotiation Negotiation algorithm Negotiable fields and effects of successful negotiation When to negotiateNegotiable fields Negotiation message pair Field name Responding message requirements Response shall beField Name Message Numerically Transfer agreements Value Description Message Transfer rate Transfer period factorTransfer period factor relationships Synchronous 12.6 REQ/ACK offset Transfer width exponent Protocol options Protocol options bitsIureq PPR negotiation setting Iureq to zero Bus phases resulting from Iureq changesSdtr negotiation PPR negotiation setting Iureq to one PPR negotiation keeping Iureq set to zero RTI Retain Training Information WrflowRdstrm Pcompen Negotiable field combinations TransferTransfer Period Message restrictions Negotiation message sequences Parallel Scsi Interface Product Manual, Rev. a Scsi bus phases overview BUS Free phaseUnexpected and expected bus free phases Expected bus free phases Arbitration and QAS overview Normal Arbitration phase QAS phase overview QAS protocol Selection phase Information unit transfers disabled Information unit transfers enabledSelection overview Selection using attention condition timeout procedure Reselection phase Reselection phase overviewPhysical reconnection Physical reconnection timeout procedure Scsi bus fairness Information transfer phases Information transfer phasesSignal Phase Direction of transfer Comment Asynchronous transfer Synchronous transferST synchronous data transfer DT synchronous transfer Information unit transferPage Data group data field transfer Page Page Page Paced transfer Paced transfer training pattern DT Data in phase training pattern Start of section aStart of section B DT Data OUT phase training pattern Start of section C 3.2 P1 data valid/invalid state transitions Starting pacing transfers at end of training pattern Starting pacing transfers with no training pattern Ending pacing transfers Paced information unit transfer Deskewing Wide transfer Command phase Data phase Status phase Message phase Message OUT phase Signal restrictions between phasesMessage in phase exception condition handling Message OUT phase exception condition handling Scsi bus phase sequences Scsi bus phase sequences overview Hard reset or protocol error Reselection Selection Arbitration DT Data Message OUT Data bus protection ST data bus protection using parityParity checking rules for Selection and Reselection phases Data bus protection overview Error detection capabilities Order of bytes in the CRC field General message protocols and formats Message formats Two-byte messages Message formatOne-byte messages Extended messages Message categories Extended Message CodesLink Control Messages Link Control message codes Key Identify message format DisconnectIdentify Bit Byte Ignore field definition Ignore Wide ResidueIgnore Wide Residue message format Invalid data bits Message Parity Error Initiator Detected ErrorLinked Command Complete Message Reject Modify Data Pointer message format Modify Bidirectional Data Pointer Modify Bidirectional Data Pointer message format No Operation Parallel Protocol Request Parallel Protocol Request message format Value 00h 01h-FEh FFh Description Timing values Use ST Data in and ST Data OUT phases to transfer data Valid protocol options bit combinationsUse QAS for arbitration Parallel Protocol Request messages implied agreement Restore Pointers QAS RequestSave Data Pointers Synchronous Data Transfer Request Synchronous Data Transfer Request message format Sdtr messages implied agreements Target initiated Sdtr negotiation Initiator initiated Sdtr negotiationTask Complete Wide Data Transfer Request Wide Data Transfer Request message format Wdtr message implied agreement Target initiated Wdtr negotiationResponding Scsi device Wdtr response Implied agreement Task attribute messages Task attribute message overview and codes Task attribute message codes ACA Auto Contingent AllegianceACA message format Head of Queue Ordered Abort Task Task management messagesTask management message codes Task management message codes 0Eh Abort Task SET Logical Unit ResetTarget Reset Clear ACA Miscellaneous Scsi bus characteristics Bus reset condition Hard reset Reset events Asynchronous condition recovery Active pointers Saved pointers Command processing considerations and exception conditions Asynchronous event notificationIncorrect initiator connection Unexpected Reselection phase SPI information units Information unit transfer logical operationsPage Parallel Scsi Interface Product Manual, Rev. a 115 116 Parallel Scsi Interface Product Manual, Rev. a Parallel Scsi Interface Product Manual, Rev. a 117 SPI command information unit SPI information units SPI command information unit Bit Byte Task Attribute Codes Description Task Management flags Codes Description SPI LQ information unit SPI LQ information unit Bit Byte Bidi Direction F0H SPI LQ information unit typeCodes Type Description FFh AllPage SPI data information unit SPI data stream information unitSPI data information unit Bit Byte SPI status data stream information unit Bit Byte SPI status information unit SPI status information unit Bit ByteReserved Reserved for FCP Packetized Failures code Codes Description SPI command information unit fields invalidPacketized Failures field Bit Byte Task management function not supportedPage 130 Parallel Scsi Interface Product Manual, Rev. a Command implementation requirements Command Descriptor Block CDBReserved Page Fixed and variable length Command Descriptor Block formats Typical CDB for 12-byte commands Bit Byte Typical CDB for 16-byte commands Bit ByteAdditional CDB Data if required Typical variable length CDB Bit Byte Operation Code 7Fh Additional CDB Length n-7Page Control field Bit Byte Last Naca aLink b Status Status precedence Command examples Single command example Disconnect example Disconnect example Timing examples Auto Contingent Allegiance or Contingent Allegiance Overlapped commands Clearing an Auto Contingent Allegiance condition Incorrect logical unit selection Sense dataAsynchronous Event Reporting Autosense Unit Attention condition Queued tasks formerly queued I/O processes Target hard resetLogical unit reset Untagged task queuing Tagged task queuing Parameter rounding Programmable operating definition Incorrect initiator connection Self-test operations Default self-testS.M.A.R.T. system Short and extended self-tests Foreground mode Background modeSelf-test modes Exception commands for background self-tests Device type a Command Reference All device types Self-test mode summary Error detection for asynchronous information phasesProtection code Covered signals Word Location Signal MeaningPage Error detection properties Code descriptionProtection code usage Enabling protection code checking Error handlingProtection code transmission Disabling protection code checking Case 1-Power off during removal or insertion SPI-3 to SCSI-2 terminology mapping SPI-3 to SCSI-2 terminology mappingSPI-3 equivalent term SCSI-2 term Index Code value reserved Disconnect privilege 148 domain 5, 9 dormant Initiator 3, 6, 14, 131, 140 faulted Multidrop 7 multimode Page Scsi Page Wdtr 40 170 Parallel Scsi Interface Product Manual, Rev. a Page Seagate Technology LLC