Transfer period factor, Synchronous | Seagate Ultra 160, Ultra 320

2.12.5Transfer period factor

The Transfer Period Factor field selects the transfer period and determines which transfer rate’s timing values in Tables 5, 6, 7, and 8 shall be honored, provided that REQ/ACK OFFSET is greater than 00h. The field val- ues are defined in Table 14.

Table 14: Transfer period factor

Value	Description	Message	Transfer rate


00h - 06h	Reserved	N/A	N/A
07h	Transfer period equals 3.125 ns	PPR	Fast-320

08h	Transfer period equals 6.25 ns	PPR	Fast-160

09h	Transfer period equals 12.5 ns	PPR	Fast-80

0Ah	Transfer period equals 25 ns	PPR, SDTR	Fast-40

0Bh	Transfer period equals 30.3 ns	PPR, SDTR	Fast-40

0Ch	Transfer period equals 50 ns	PPR, SDTR	Fast-20

0Dh - 18h	Transfer period equals the TRANSFER PERIOD FACTOR x 4	PPR, SDTR	Fast-20

19h - 31h	Transfer period equals the TRANSFER PERIOD FACTOR x 4	PPR, SDTR	Fast-10

32h - FFh	Transfer period equals the TRANSFER PERIOD FACTOR x 4	PPR, SDTR	Fast-5

Table 15 shows which transfer period factors may be used with different types of transfer agreements, provided REQ/ACK OFFSET is greater than 00h.

	Table 15:	Transfer period factor relationships

				Transfer agreement
	Value
	Value	Synchronous	Paced	Data group		Information	ST data	DT data
						Information
						unit
						unit


	00h - 06h				Reserved
	07h - 08h	NS	M	NS		M	NS	M

	09h	M	NS	O		O	NS	M

	0Ah	M	NS	O		O	O	O

	0Bh	M	NS	O		O	O	O

	0Ch	M	NS	O		O	O	O

	0Dh - 18h	M	NS	O		O	O	O

	19h - 31h	M	NS	O		O	O	O

	32h - FFh	M	NS	O		O	O	O

Table abbreviations are defined as follows:

M = Mandatory: Support for the indicated transfer agreement shall be implemented if the indicated transfer period factor is implemented.

O = Optional: Support for the indicated transfer agreement may be implemented if the indicated transfer period factor is implemented.

NS = Not Supported: The indicated transfer agreement shall not be allowed if the indicated transfer factor is selected.

Table 20 defines valid combinations of TRANSFER PERIOD FACTOR and other fields.

Parallel SCSI Interface Product Manual, Rev. A )

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Seagate Ultra 160 manual Transfer period factor relationships, Value Description Message Transfer rate, Synchronous

Contents

Parallel Scsi Interface Page Parallel Scsi Interface Page Revision Date Writer/Engineer Revision status summary sheet Parallel Scsi Interface Product Manual, Rev. a Table of Contents Parallel Scsi Interface Product Manual, Rev. a Wide transfer Logical characteristics Message system specification Miscellaneous Scsi bus characteristics Scsi commandsSPI information units Drive features List of Figures Xii Parallel Scsi Interface Product Manual, Rev. a Interface requirements How to use this interface manual Scope of Scsi standards Applicable standards General interface description Scsi client-server model GlossaryPage Page Page Page Page Page Keywords Physical interface characteristics Summary of Scsi messagesMessage Name Hex Code Number Scsi bus Priority Scsi IDs and associated Scsi bus arbitration priorities Scsi bus signals overview Scsi target usage of Pcrca Pcrc signal usage requirements Signal values Signal statesSE signals LVD signals Voltage and current definitions OR-tied signals Signal sources Signal sourcesData bit P cable Data bit a cable I/O DB15-8 Scsi bus phase DB7-0 Scsi bus control timing values in nanoseconds Scsi bus timingTiming Reference Type Value ns Unless Timing description Timing values for negotiated transfer rate Scsi bus data and information phase ST timing valuesNanoseconds unless otherwise noted 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 ATN receive setup time ATN transmit setup timeCrosstalk time shift ISI of data Bus free delay Bus clear delayBus set delay Bus settle delay Flow control transmit setup time Flow control receive setup timePCRC receive setup time PCRC transmit setup time Physical disconnection delay Data release delayPower on to selection QAS arbitration delay Receive setup time Receive internal setup timeReceive internal hold time Receive negation period Reset hold time Reset delayReset to selection Residual skew error Skew correction range System deskew delayStrobe offset tolerance System noise at launch Measurement points LVD measurement points Clocking methods for data transfers ST latching data vs. DT latching data DT synchronous transfer example Paced transfer on a Scsi bus Asynchronous transfers Data transfer modesSynchronous transfers Paced transfers DT Data phase parallel transfers ST Data phase parallel transfersData group transfers Information unit transfers Negotiation algorithm Negotiation Negotiable fields When to negotiateNegotiable fields and effects of successful negotiation Negotiation message pair Field name Responding message requirements Response shall beField Name Message Numerically Transfer agreements Transfer period factor relationships Transfer period factorValue Description Message Transfer rate Synchronous Transfer width exponent 12.6 REQ/ACK offset Protocol options Protocol options bitsIureq Sdtr negotiation PPR negotiation setting Iureq to one Bus phases resulting from Iureq changesPPR negotiation setting Iureq to zero PPR negotiation keeping Iureq set to zero Rdstrm WrflowRTI Retain Training Information Pcompen Negotiable field combinations TransferTransfer Period Negotiation message sequences Message restrictions Parallel Scsi Interface Product Manual, Rev. a Scsi bus phases overview BUS Free phaseUnexpected and expected bus free phases Arbitration and QAS overview Expected bus free phases Normal Arbitration phase QAS protocol QAS phase overview Selection phase Information unit transfers disabled Information unit transfers enabledSelection overview Selection using attention condition timeout procedure Reselection phase Reselection phase overviewPhysical reconnection Scsi bus fairness Physical reconnection timeout procedure Information transfer phases Information transfer phasesSignal Phase Direction of transfer Comment Asynchronous transfer Synchronous transferST synchronous data transfer Information unit transfer DT synchronous transferPage Data group data field transfer Page Page Page Paced transfer training pattern Paced transfer DT Data in phase training pattern Start of section aStart of section B Start of section C DT Data OUT phase training pattern 3.2 P1 data valid/invalid state transitions Starting pacing transfers with no training pattern Starting pacing transfers at end of training pattern Paced information unit transfer Ending pacing transfers Wide transfer Deskewing Data phase Command phase Message phase Status phase Message in phase exception condition handling Signal restrictions between phasesMessage OUT phase Message OUT phase exception condition handling Scsi bus phase sequences overview Scsi bus phase sequences Hard reset or protocol error Reselection Selection Arbitration DT Data Message OUT Parity checking rules for Selection and Reselection phases ST data bus protection using parityData bus protection Data bus protection overview Order of bytes in the CRC field Error detection capabilities Message formats General message protocols and formats One-byte messages Message formatTwo-byte messages Extended messages Message categories Extended Message CodesLink Control Messages Link Control message codes Key Identify DisconnectIdentify message format Bit Byte Ignore Wide Residue message format Ignore Wide ResidueIgnore field definition Invalid data bits Linked Command Complete Initiator Detected ErrorMessage Parity Error Message Reject Modify Bidirectional Data Pointer Modify Data Pointer message format No Operation Modify Bidirectional Data Pointer message format Parallel Protocol Request message format Parallel Protocol Request 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 message format Synchronous Data Transfer Request Sdtr messages implied agreements Target initiated Sdtr negotiation Initiator initiated Sdtr negotiationTask Complete Wide Data Transfer Request message format Wide Data Transfer Request Wdtr message implied agreement Target initiated Wdtr negotiationResponding Scsi device Wdtr response Implied agreement Task attribute message overview and codes Task attribute messages Task attribute message codes ACA Auto Contingent AllegianceACA message format Ordered Head of Queue Task management message codes Task management message codes Task management messagesAbort Task 0Eh Target Reset Logical Unit ResetAbort Task SET Clear ACA Miscellaneous Scsi bus characteristics Hard reset Bus reset condition Asynchronous condition recovery Reset events Saved pointers Active pointers Command processing considerations and exception conditions Asynchronous event notificationIncorrect initiator connection Unexpected Reselection phase Information unit transfer logical operations SPI information unitsPage 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 information units SPI command information unit SPI command information unit Bit Byte Task Management flags Codes Description Task Attribute Codes Description SPI LQ information unit Bit Byte SPI LQ information unit Bidi Direction Codes Type Description SPI LQ information unit typeF0H 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 field Bit Byte SPI command information unit fields invalidPacketized Failures code Codes Description 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 Additional CDB Length n-7 Typical variable length CDB Bit Byte Operation Code 7FhPage Control field Bit Byte Last Naca aLink b Status Status precedence Single command example Command examples Disconnect example Disconnect example Auto Contingent Allegiance or Contingent Allegiance Timing examples Clearing an Auto Contingent Allegiance condition Overlapped commands Incorrect logical unit selection Sense dataAsynchronous Event Reporting Autosense Unit Attention condition Logical unit reset Target hard resetQueued tasks formerly queued I/O processes Untagged task queuing Tagged task queuing Programmable operating definition Parameter rounding Incorrect initiator connection S.M.A.R.T. system Default self-testSelf-test operations Short and extended self-tests Foreground mode Background modeSelf-test modes Device type a Command Reference All device types Exception commands for background self-tests Self-test mode summary Error detection for asynchronous information phasesProtection code Word Location Signal Meaning Covered signalsPage Error detection properties Code descriptionProtection code usage Protection code transmission Error handlingEnabling protection code checking 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