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Seagate Ultra 160 Product Manual

Parallel scsi interface
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Parallel SCSI Interface

Ultra 160
Ultra 320

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  • Page 1: Parallel Scsi Interface

    Parallel SCSI Interface Ultra 160 Ultra 320...
  • Page 3 Parallel SCSI Interface Ultra 160 Ultra 320...
  • Page 4 Seagate Technology LLC. Other product names are registered trade- marks or trademarks of their owners. Seagate reserves the right to change, without notice, product offerings or specifications. No part of this publication may be reproduced in any form without written permission of Seagate Technology LLC.
  • Page 5 Revision status summary sheet Revision Date Writer/Engineer Sheets Affected Rev. A 03/27/06 C. Chalupa/G. Houlder All. Parallel SCSI Interface Product Manual, Rev. A...
  • Page 6 Parallel SCSI Interface Product Manual, Rev. A...

  • Page 7: Table Of Contents

    Interface requirements ............1 1.1 How to use this interface manual .
  • Page 8 2.5.35 Receive setup time ............30 2.5.36 Receive REQ(ACK) period tolerance .
  • Page 9 2.12.8.3QAS_REQ ............46 2.12.8.4HOLD_MCS .
  • Page 10 3.7.1 DATA phase overview ........... . . 75 3.7.2 DT DATA IN phase .
  • Page 11 4.3.16 SYNCHRONOUS DATA TRANSFER REQUEST ....... 97 4.3.16.1Target initiated SDTR negotiation ........99 4.3.16.2Initiator initiated SDTR negotiation .
  • Page 12 7.3.1 Status precedence............139 7.4 Command examples.
  • Page 13 Figure 1. SCSI client-server model ........... . . 4 Figure 2.
  • Page 14 Parallel SCSI Interface Product Manual, Rev. A...

  • Page 15: Interface Requirements

    This manual provides a description of the SCSI1 interface protocol and some general timing information as implemented by Seagate products. The features described in this manual are typically referred to as “Ultra160 SCSI” or “Ultra320 SCSI” features. Individual drive’s Product Manual, for the various SCSI interface products, contains additional and more detailed information on protocol, features supported, timing, and electrical/ mechanical aspects of how the SCSI interface is implemented by that product.

  • Page 16: Scope Of Scsi Standards

    1.1.1 Scope of SCSI standards Figure 1 uses a representative set of specifications to show the functional partitions and the relationships among SCSI standards applicable to drives covered by this manual. SCSI Block Commands (SBC) SCSI Primary Commands (SPC) Interlocked Protocol Interface (SPI-3) Figure 1.

  • Page 17: Applicable Standards

    SCSI Interface Specifications listed in Section 1.1.2. The drives covered by this manual are classified as “Intel- ligent” peripherals. The Seagate SCSI interface described herein consists of a 9 or 18 bit bidirectional data bus (includes bits for parity checking and enabling CRC protection), plus 9 control signals. The SCSI interface supports multiple ini-...

  • Page 18: Glossary

    Application Client Initiator Figure 2. SCSI client-server model 1.2.1 Glossary aborted command—A SCSI command that has been ended by aborting the task created to execute it. ACA—Auto Contingent Allegiance (see below). additional sense code—a combination of the ADDITIONAL SENSE CODE and ADDITONAL SENSE CODE QUALIFIER in the sense data (see SPC-4) application client—An object that is the source of SCSI commands.
  • Page 19 The complete definition of the Control mode page is found in the Seagate SCSI Command Reference Manual, Part number 100293068, or SPC-4.
  • Page 20 double transition (DT)—The latching of data on both the assertion edge and the negated edge of the REQ or ACK signals. driver—The circuitry used to control the state of the bus. enabled task state—The state of a task that may complete at any time. Alternatively, the state of a task that is waiting to receive the next command in a series of linked commands.
  • Page 21 I/O operation—An operation defined by an unlinked SCSI command, a series of linked SCSI commands or a task management function. I/O process—An I/O process consists of one initial connection or, if information units are enabled, the establishment of a nexus, and a zero or more physical or logical reconnection all pertaining to a single task or a group of tasks.
  • Page 22 nexus—A relationship between a SCSI initiator port and a SCSI target port, logical unit, or queue tag that begins with an initial connection and ends with the completion of the associated I/O process. This relationship is formed as the result of a task. object—An architectural abstraction or “container”...
  • Page 23 protocol service request—A call to the lower level protocol service layer to begin a protocol service transac- tion. protocol service response—A reply from the upper level protocol layer in response to a protocol service indi- cation. quick arbitration and selection process (QAS)—Quicker than the normal arbitration and selection process. Implementation is optional for SCSI devices.
  • Page 24 service delivery transaction—A request or response sent through the service delivery subsystem. signal—(n) A detectable asynchronous event possibly accompanied by descriptive data and parameters. (v) The act of generating such an event. single transition (ST)—The latching of data only on the assertion edge of the REQ or ACK signals. source device—The SCSI device from which a service delivery transaction originates.

  • Page 25: Keywords

    third-party command—A SCSI command which requires a logical unit within the target device to assume the initiator role and send a SCSI command to a SCSI target port device. transaction—A cooperative interaction between two objects, involving the exchange of information or the exe- cution of some service by one object on behalf of the other.

  • Page 26: Physical Interface Characteristics

    Physical interface characteristics The physical interface characteristics (cables, connectors, electrical descriptions, termination requirements, etc.) for the drives covered by this Interface Manual are found in each individual drive’s Product Manual, since these features are not the same for all drives. Summary of SCSI messages Following is an alphabetical summary of the SCSI messages described in this manual.

  • Page 27: Scsi Bus

    For all of the physical details of the SCSI interface, consult the ANSI standards referenced in Sec- tion 1.1.2. Communication on the SCSI Bus is allowed between only two SCSI devices at a time. Seagate drives support systems with a maximum of 16 SCSI devices including the host computer(s) connected to the SCSI bus. Each SCSI device has a SCSI ID bit assigned as shown in Table 1.
  • Page 28 Table 1: SCSI IDs and associated SCSI bus arbitration priorities SCSI address Key: - = a logical 0 bit resulting from the data bus bit being released The Host Adapter/Initiator must be identified by one of the 16 SCSI Device IDs (usually 7, which is highest arbi- tration priority).

  • Page 29: Scsi Bus Signals Overview

    SCSI bus signals overview Information transfer on the SCSI bus is allowed between only two SCSI devices at any given time except dur- ing MESSAGE IN PHASE when QAS is enabled. All SCSI devices that have QAS enabled are required to monitor messages during a MESSAGE IN PHASE for a QAS REQUEST MESSAGE.
  • Page 30 During the SELECTION PHASE, RESELECTION PHASE, ST DATA PHASE, COMMAND PHASE, MESSAGE PHASE, and STATUS PHASE, this signal is referred to as DB(P_CRCA) and is sourced by the SCSI device port driving the Data Bus. The DB(P_CRCA) signal is associated with the DB(7-0) signals and is used to detect the presence of an odd number of bit errors within the byte.

  • Page 31: Drive Select

    When information unit transfers are enabled, the P1 signal shall be continuously negated by the SCSI device driving the DB(15-0) signals and shall be ignored by the SCSI device receiving the DB(15-0) signals during DT DATA phases. During DT DATA phases when information unit transfers and paced transfers are enabled the P1 signal shall be sourced by the SCSI device driving the DATA BUS.

  • Page 32: Or-Tied Signals

    Figure 3. Voltage and current definitions Figure 4 defines the signaling sense of the voltages appearing on the – signal and + signal lines as follows: a. The – signal terminal of the driver shall be negative with respect to the + signal terminal for an asserted state.

  • Page 33: Signal Sources

    Signal sources Table 3 indicates the type of SCSI device allowed to source each signal. No attempt is made to show if the source is driving asserted, driving negated, or is released. All SCSI device drivers that are not active sources shall be in the high-impedance state.

  • Page 34: Scsi Bus Timing

    SCSI bus timing Unless otherwise indicated, the delay time measurements for each SCSI device, defined in paragraphs 2.5.1 through 2.5.60 shall be calculated from signal conditions existing at that SCSI device’s own SCSI bus connec- tion. Thus, these measurements (except skew delay) can be made without considering delays in the cable. Refer to the tables below for the actual timing values for these delays.
  • Page 35 Table 5: SCSI bus data and information phase ST timing values Timing description ATN transmit setup time ATN receive setup time Cable skew Receive assertion period Receive hold time [3] [4] Receive negation period Receive setup time [3] [4] Receive REQ(ACK) period tolerance Signal timing skew REQ(ACK) period Transmit assertion period...
  • Page 36 Cable skew is measured at each SCSI device connection within the same bus segment with the transmit- ted skew subtracted from the received skew. Calculated assuming timing budget shown in Table 9. Measured at the receiver terminal using clean input signals with 500 mV peak amplitude and 1 ns rise and fall time between 20% and 80% of the signal.
  • Page 37 Table 7: Transmit SCSI bus data and information phase DT timing values Timing description Reference ATN transmit setup time Flow control transmit hold time Flow control transmit setup time pCRC transmit hold time pCRC transmit setup time Transmit assertion period Transmit hold time [2] [3] Transmit ISI compensation...
  • Page 38 Table 8: Receive SCSI bus data and information phase DT timing values Timing description Reference ATN receive setup time Flow control receive hold time Flow control receive setup time pCRC receive hold time pCRC receive setup time Receive assertion period Receive hold time [2] [3] Receive negation period...
  • Page 39 Table 9: SCSI Fast-160 and fast 320 non-compensatable timing budget in nanoseconds Item REQ(ACK) period Transfer period Transmitter and receiver errors: Transmitter errors: REQ(ACK) period tolerance / 2 Clock Jitter System noise at transmitter Transmitter chip skew Transmitter trace skew Transmit time asymmetry Total transmitter error budget: Receiver errors:...

  • Page 40: Arbitration Delay

    Table 10: SCSI fast-160 and fast-320 interconnect timing budget in nanoseconds Item Nominals: REQ(ACK) period Transfer period Transmitter and receiver errors: Interconnect errors: Cable skew Crosstalk time shift ISI of data Total interconnect budget See 2.5.8. The residual deskew error is included in the receiver error budget. Note.

  • Page 41: Bus Clear Delay

    When information unit transfers are being used with synchronous transfers, the ATN receive setup time is the minimum time required at the receiver between the assertion of the ATN signal and the negation of the ACK signal corresponding to the last iuCRC transfer of an information unit to recognize the assertion of an attention condition.

  • Page 42: De-Skewed Data Valid Window

    2.5.12 De-skewed data valid window The minimum difference in time allowed between the rising or falling edge of a “1010...” pattern on the DAT BUS or DB(P1) and its clocking signal on the ACK or REQ signal as measured at their zero-crossing points after skew compensation is applied by the receiver without allowing any error in the received data.

  • Page 43: Data Release Delay

    2.5.21 Data release delay The maximum time for a SCSI initiator port to release the DATA BUS, DB(P_CRCA), and/or DB(P1) signals, following the transition of the I/O signal from false to true. 2.5.22 DIFFSENS voltage filter time The minimum time DIFFSENS voltage shall be sensed continuously within the voltage range of a valid SCSI bus mode.

  • Page 44: Receive Internal Hold Time

    DB(P1) signals. For paced data transfers negative values as measured at the device connector are accommo- dated by skew compensation in the receiver. Receive hold time measured at the device connector shall not exceed the skew correction range. 2.5.32 Receive internal hold time The minimum time provided for hold time in the receive data detector after allowance for timing errors and tim- ing compensation from all sources measured from the worst-case bit (i.e., data or parity) to the compensated offset strobe.

  • Page 45: Receiver Amplitude Time Skew

    2.5.40 Receiver amplitude time skew The maximum time shift of SCSI bus signals caused by the difference in receiver switching delay of a minimum amplitude signal versus a maximum amplitude signal. 2.5.41 REQ(ACK) period The REQ(ACK) period during synchronous transfers or paced transfers is the nominal time between adjacent assertion edges of the REQ or ACK signal for the fastest negotiated transfer rate.

  • Page 46: Skew Correction Range

    pensation. 2.5.49 Skew correction range The minimum skew correction capability of the receiver of a signal on the DATA BUS or DB(P1) relative to the ACK or REQ signal as measured at the receiver’s connector. The skew correction range shall be equal to: +/–...

  • Page 47: Transmit Setup Time

    The minimum time that a SCSI target port shall negate the REQ signal while using synchronous transfers or paced transfers, provided it is not transitioning P_CRCA during data group transfers. Also, the minimum time that a SCSI initiator port shall negate the ACK signal while using synchronous transfers or paced transfers. 2.5.59 Transmit setup time For ST data transfers, the minimum time provided by the transmitting SCSI device between the changing of...

  • Page 48: Lvd Measurement Points

    SE SCSI devices with data transfer rates up to and including Fast-20 shall use the measurement points defined in Section 9 of ANSI standard SPI-4, for the measurement of the timing values. The rise and fall times for the SE REQ/ACK signals shall be nominally the same as for the SE Data, DB(P_CRCA), and DB(P1) sig- nals.
  • Page 49 Figure 8 shows an example of transfers with a negotiated transfer period of 6.25 ns at the receiving SCSI device’s connector. There is no difference as to when data is latched on paced transfers, however, the relation- ship between the data and REQ or ACK is required to be adjusted in the SCSI devices receiver to match the synchronous transfers DT Data shown in Figure 5.

  • Page 50: Paced Transfer On A Scsi Bus

    REQ or ACK DT Data Figure 7. DT synchronous transfer example REQ or ACK DT Data Clock Figure 8. Paced transfer example Paced transfer on a SCSI bus A SCSI bus that supports paced transfers has additional driver and receiver functions required over those used with synchronous transfers or asynchronous transfers.

  • Page 51: Data Transfer Modes

    The receiver skew compensation and clock shifting adjust the timing relationship between the clocking signal (i.e., REQ or ACK) and the signals being clocked (e.g., the data bus signals). That adjustment causes the clock signal to align with the middle of the signals being clocked when those signals enter the receiver. The receiver is then able to the clock signal to latch valid data.

  • Page 52: St Data Phase Parallel Transfers

    2.10 ST DATA phase parallel transfers The format of data transmitted during ST DATA phases consists of data and protection. Parity generation and checking give some error detection protection in the ST phase data. 2.11 DT DATA phase parallel transfers During DT DATA phases, communicating SCSI devices format information according to one of two protocol options: •...

  • Page 53: Negotiation

    The iuCRC shall be used to protect all SPI information units. The SCSI device that originates the SPI informa- tion unit sends the necessary pad bytes and iuCRC fields. An iuCRC interval may also be specified. The iuCRC interval specifies the number of bytes transferred before pad bytes (if any) and the iuCRC is transferred within SPI data information units and SPI data stream informa- tion units.

  • Page 54: When To Negotiate

    If the responding negotiation message contains values the originating port does not support, the originating port shall respond with a MESSAGE REJECT message. 2.12.2 When to negotiate Each port shall maintain a negotiation required flag for each other port. A port shall set its negotiation required flags to true for all other ports after a reset event.
  • Page 55 Table 11: Negotiable fields and effects of successful negotiation Field name PCOMP_EN RD_STRM WR_FLOW Protocol options HOLD_MCS QAS_REQ DT_REQ IU_REQ When negotiating, the responding port shall respond with values that are a subset of the values in the originat- ing message as indicated in Table 12 (e.g., if the originating message requests a REQ/ACK offset of 10h, the responding message has a REQ/ACK offset field set to 10h or lower).

  • Page 56: Transfer Agreements

    2.12.4 Transfer agreements The transfer agreements that are in effect for various combinations of field values are described in Table 13. Table 13: Transfer agreements Transfer Transfer REQ/ACK agreement offset Default Asynchronous GE 01h GE 09h Synchronous GE 01h GE 0Ah ST synchronous GE 01h GE 09h...

  • Page 57: Transfer Period Factor

    2.12.5 Transfer 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.

  • Page 58: Req/Ack Offset

    2.12.6 REQ/ACK offset The REQ/ACK OFFSET field determines the maximum number of REQs allowed to be outstanding before a corresponding ACK is received at the SCSI target port during synchronous or paced transfers. For ST synchro- nous transfers the REQ/ACK offset is the number of REQ assertions that may be sent by the SCSI target port in advance of the number of ACK assertions received from the SCSI initiator port.

  • Page 59: Protocol Options

    2.12.8 Protocol options The protocol options fields affect the protocol used between the ports. The SCSI target port uses the protocol options bits to indicate to the SCSI initiator port if it agrees to enable the requested protocol options. Except for the PCOMP_EN bit, the SCSI target port shall not enable any protocol options that were not enabled in the negotiation message received from the SCSI initiator port.

  • Page 60: 2Dt_Req

    Table 19 describes the bus phases resulting from IU_REQ changes. Table 19: Bus phases resulting from IU_REQ changes Modified Initial IU_REQ IU_REQ value a. PPR negotiation keeping IU_REQ set to zero; b. WDTR negotiation; or c. SDTR negotiation a. PPR negotiation setting IU_REQ to one a.

  • Page 61: 6Rd_Strm

    Table 20 defines valid combinations of HOLD_MCS and other fields. 2.12.8.5 WR_FLOW The SCSI initiator port shall set WR_FLOW to one to indicate that the SCSI target port should enable write flow control during write streaming. In response, the SCSI target port shall set WR_FLOW to one if it is capable of write flow control and zero if it is not.

  • Page 62: Negotiable Field Combinations

    2.12.9 Negotiable field combinations Not all combinations of the negotiable fields are valid. Only the combinations defined in Table 20 shall be allowed. All other combinations of the listed fields are reserved. Table 20: Valid negotiable field combinations Transfer REQ/ Transfer period width...

  • Page 63: Message Restrictions

    2.12.10 Message restrictions PPR may be originated by SCSI initiator ports but shall not be originated by SCSI target ports. If bus expanders are present, SCSI initiator ports should only use PPR when requesting values not attainable via WDTR and SDTR (e.g., setting any protocol option bits to one).
  • Page 64 Parallel SCSI Interface Product Manual, Rev. A )

  • Page 65: Logical Characteristics

    Logical characteristics The operations of the SCSI bus as described in this section are supported by the drive as specified in each individual drive’s Product Manual. The drive always functions as the target unless otherwise stated. SCSI bus phases overview The drive responds to the following phases: BUS FREE phase ARBITRATION phase...

  • Page 66: Expected Bus Free Phases

    a. after any bus reset event. b. after a transceiver mode change reset event. c. after an Abort Task management function is successfully received by a SCSI target port; d. after an Abort Task Set management function is successfully received by a SCSI target port; e.

  • Page 67: Normal Arbitration Phase

    (see Section 3.4). Fairness in normal arbitration is enabled in targets by the Disconnect-Reconnect mode page (see Seagate SCSI Command Reference Manual, Part number 100293068). Fairness is always enabled when QAS is enabled.

  • Page 68: Qas Protocol

    3.1.2.2 QAS protocol Quick Arbitration and Selection (QAS) allows a SCSI target port with an information unit transfer agreement in effect and QAS enabled (see Section 4.3.12) that is currently connected to a SCSI initiator port that has infor- mation unit transfers enabled and QAS enabled to transfer control of the bus to another SCSI device that has information unit transfers enabled and QAS enabled without an intervening BUS FREE phase.

  • Page 69: Selection Phase

    4. If the SCSI initiator creates an attention condition, the SCSI target port shall go to a MESSAGE OUT phase, receive all the message bytes, and cause an unexpected bus free by generating a BUS FREE phase (see Section 3.1.1.1 on page 51). 5.

  • Page 70: Selection Overview

    Refer to Section 3.4 for a description of the fairness algorithm which applies during SELECTION and RESE- LECTION phases. 3.2.1 Selection overview The SCSI device that won a normal arbitration has both the BSY and SEL signals asserted and has delayed at least one bus clear delay plus a bus settle delay before ending the normal ARBITRATION phase.

  • Page 71: Selection Using Attention Condition Timeout Procedure

    3.2.1.1.4 Selection using attention condition timeout procedure Two optional selection timeout procedures are specified for clearing the SCSI bus if the initiator waits a mini- mum of one selection timeout delay and there has been no BSY signal response from the target: •...

  • Page 72: Reselection Phase

    (a) Optionally, the initiator shall assert the RST signal (see Section 5.3); (b) Optionally, the initiator shall continue asserting the SEL signal and shall release the Data Bus, DB(P_CRCA), or DB(P1). If the initiator has not detected the BSY signal to be true after at least one selection abort time plus two system deskew delays, the initiator shall release the SEL signal allowing the SCSI bus to go to the BUS FREE phase.

  • Page 73: Physical Reconnection Timeout Procedure

    glitch may cause the BSY signal to appear false for up to a round-trip propagation delay following the release of the BSY signal by the initiator. This is the reason why the BUS FREE phase is recognized only after both the BSY and SEL signals are continuously false for a minimum of one bus settle delay. For more information on glitches, see ANSI SPI-5, T10/1525D.

  • Page 74: Information Transfer Phases

    Information transfer phases The COMMAND, DATA, STATUS, and MESSAGE phases are grouped together as information transfer phases because they are all used to transfer data or control information via the data bus. The actual contents of the information is beyond the scope of this section. The C/D, I/O, and MSG signals are used to distinguish between the different information transfer phases (see Table 21).

  • Page 75: Asynchronous Transfer

    Synchronous transfers shall only be used for negotiated transfer rates less than or equal to Fast-80. Paced transfers shall only be used for a negotiated transfer rate of Fast-160. 3.5.1 Asynchronous transfer The target shall control the direction of information transfer by means of the I/O signal. When the I/O signal is true, information shall be transferred from the target to the initiator.

  • Page 76: Dt Synchronous Transfer

    hold time after the assertion of the REQ signal. The target shall assert the REQ signal for a minimum of one transmit assertion period. The target may then negate the REQ signal and change or release the DB(7- 0,P_CRCA) or DB(15-0,P_CRCA,P1) signals. The initiator shall read the value on the DB(7-0,P_CRCA) or DB(15-0,P_CRCA,P1) signals within one receive hold time of the transition of the REQ signal to true.
  • Page 77 3. shall delay at least one transmit setup time; 4. shall transition the ACK signal; 5. shall hold the DB(15-0) signals valid for at least one transmit hold time; 6. shall not change the ACK signal for a minimum of one transmit assertion period; and 7.

  • Page 78: Data Group Data Field Transfer

    ABORT TASK message (see Section 4.5.2) to the target. The target shall send a SPI L_Q/SPI status informa- tion unit pair to the initiator with a CHECK CONDITION status and a sense key set to Aborted Command for the task associated with the received ABORT TASK message. 3.5.2.2.1.2 DT DATA OUT phase information unit transfer exception condition handling The target shall only respond to an iuCRC error after all the data in an information unit has been received.
  • Page 79 2. read the value of the P_CRCA signal within one pCRC receive hold time of the transition of the REQ signal; and 3. respond with an ACK transition. If the I/O signal is false (i.e., transfer to the target), to transfer the data field, the initiator: 1.
  • Page 80 Note. The above requirements in steps 6), 10), and 14) to not wait for the ACK transition corresponding to the previous REQ transition were not present in the SPI-3 standard. For compatibility with old designs SCSI initiator ports should generate ACK transitions for all received REQ transitions. If the SCSI target port determines that a pad field is not required, has completed the data field transfer of the current data group, the I/O signal is true (i.e., transfer to the SCSI initiator port), and the REQ signal is negated, the SCSI target port shall:...
  • Page 81 Pad field data and pCRC field data are transferred using the same negotiated transfer period as the data field data. The target may continue to send REQs, up to the negotiated offset, for the next data group. The target shall not transition REQ with P_CRCA asserted until the initiator has responded with all ACK transitions for the previous data group.

  • Page 82: Paced Transfer

    The target shall read the value of the DB(15-0) signals within one receive hold time of the transition of the ACK signal. The initiator shall use the pad bytes, if any, in the generation of the transmitted pCRC. The target shall then use those pad bytes, if any, for checking against the computed pCRC for the current data group.

  • Page 83: Dt Data In Phase Training Pattern

    If the retain training information is enabled, a training pattern shall be transferred at the start of the first DT DATA phase for each data transfer direction after the retain training information is enabled. The SCSI device shall save training configuration values for each I_T nexus that has negotiated to retain training information. The SCSI device shall use the saved training configuration values for all paced transfers.

  • Page 84: Dt Data Out Phase Training Pattern

    4. simultaneously assert and negate P1, P_CRCA, and DB(15-0) signals at twice the negotiated transfer period (i.e., simultaneously repeat a 1100b bit pattern 12 times on each signal) while asserting and negating REQ at the negotiated transfer period 24 times [e.g., (2 x 6.25 ns) x 24 = 300 ns at Fast-160]; Start of section C 1.

  • Page 85: P1 Data Valid/Invalid State Transitions

    The SCSI initiator port shall begin the section A of its training pattern independent of the start of the SCSI tar- get ports training pattern if it detects the SEL and MSG true, and C/D and I/O false on the first assertion of the REQ signal.

  • Page 86: Starting Pacing Transfers At End Of Training Pattern

    The data invalid state shall have at least one transition of P1 before changing states. The minimum data invalid time is four transfer periods. This ensures a maximum run length of three cycles for P1. The data invalid state shall last an even number of transfer periods. From the data invalid state, the sending SCSI device port may resume sending data by reversing the phase of P1 again.

  • Page 87: Ending Pacing Transfers

    The SCSI target port shall begin pacing transfers only after meeting all the following: • signal restrictions between information transfer phases listed in Section 3.10; • the signal restrictions between a RESELECTION phase and a DT DATA IN phase listed in Section 3.3.2; or •...

  • Page 88: Deskewing

    (e) shall hold the DB(15-0) signals valid for a minimum of one transmit hold time. If the I/O signal is false (i.e., transfer to the SCSI target port), to receive SPI information units the SCSI target port: (a) shall read the value of the DB(15-0 signals within one receive hold time of the transition of the ACK signal.

  • Page 89: Command Phase

    Table 22: Wide SCSI byte order SCSI bus Transfer number 15...8 When transferring consecutive bytes W, X, Y, and Z across the buses, they are transferred as shown above. This table does not necessarily represent how these bytes are stored in device memory.

  • Page 90: Dt Data Out Phase

    3.7.3 DT DATA OUT phase The DT DATA OUT phase allows the SCSI target port to request that data be sent from the SCSI initiator device to the SCSI target device using DT data transfers. The target shall assert the MSG signal and negate the C/D and I/O signals during the REQ/ACK handshakes of this phase.

  • Page 91: Message In Phase Exception Condition Handling

    A QAS-capable SCSI initiator port shall assert ACK for a minimum of one QAS non-data phase REQ(ACK) period. 3.9.2.1 MESSAGE IN phase exception condition handling If the SCSI initiator port detects a parity error on any message byte it receives, the SCSI initiator port shall cre- ate an attention condition.

  • Page 92: Scsi Bus Phase Sequences

    d. When switching the Data Bus or DB(P_CRCA) signal direction from out (SCSI initiator port driving) to in (SCSI target port driving), the target shall delay driving the Data Bus, DB(P_CRCA), and/or DB(P1) by at least one data release delay plus one bus settle delay after asserting the I/O signal, and the initiator shall release the Data Bus, DB(P_CRCA), and/or DB(P1) no later than one data release delay after the transition of the I/O signal to true.

  • Page 93: Information Unit Transfers Disabled

    The final information transfer phase is normally the MESSAGE IN phase where a DISCONNECT or TASK COMPLETE message is transferred, followed by the BUS FREE phase. Hard reset or protocol error BUS FREE Figure 11. Phase sequences for physical reconnection and selection using attention condition with information unit transfers disabled 3.11.3 Phase sequences for selection without using attention condition with information unit...

  • Page 94: Phase Sequences For Physical Reconnection Or Selection Without Using Attention Condition With Information Unit Transfers Enabled

    3.11.4 Phase sequences for physical reconnection or selection without using attention condition with information unit transfers enabled The sequences for physical reconnection or selection without using attention condition while an information unit transfer agreement is in effect shall be as shown in Figure 13. The normal progression for selection without using attention condition (see Section 3.2.1.1.3) if QAS is dis- abled is: 1.

  • Page 95: Information Unit Transfers Enabled

    3.11.5 Phase sequences for physical selection using attention condition with information unit transfers enabled The sequences for a selection with attention condition while an information unit transfer agreement is in effect shall be as shown in Figure 14. The normal progression for selection using attention condition (see Section 3.2.1.1.3) if QAS is disabled is: 1.

  • Page 96: Dt Data Bus Protection Using Crc

    For COMMAND, MESSAGE, and STATUS phases, the DB(P_CRCA) signal shall indicate odd parity for DB(7- 0). The DB(P1) signal shall not be checked. For ST DATA phases, the DB(P_CRCA) signal shall indicate odd parity for DB(7-0). If 8-bit transfers are enabled, the DB(P1) signal shall not be checked.

  • Page 97: Message System Specification

    Message system specification SCSI protocol messages allow communication between a SCSI initiator port and a SCSI target port for the pur- pose of link management. The link management messages used for this purpose are defined within this stan- dard and their use is confined to this standard. Other SCSI protocol messages allow communication between the application client and the task manager for the purpose of task management.

  • Page 98: One-Byte Messages

    Table 24: Message format Message code Message format One-byte message (TASK COMPLETE) Extended messages 02h–0Ah One-byte messages Obsolete one-byte messages 0Ch–0Eh One-byte messages 0Fh–10h Reserved one-byte messages 11h–13h Obsolete one-byte messages 14h–15h Reserved one-byte messages 16h–17h One-byte messages 20h–24h Two-byte messages 25h–2Fh Reserved two-byte messages 30h–54h...

  • Page 99: Message Categories

    Table 26: Extended Message Codes Code Extended message MODIFY DATA POINTERS SYNCHRONOUS DATA TRANSFER REQUEST Reserved WIDE DATA TRANSFER REQUEST PARALLEL PROTOCOL REQUEST MODIFY BIDIRECTIONAL DATA POINTER 06h - FFh Reserved 1. The EXTENDED MESSAGE ARGUMENTS are specified within the Extended Message Descriptions in Paragraphs referenced in Table 27.
  • Page 100 Support IU transfers IU transfers disabled enabled Code Init Targ Init 01h,03h,01h 01h,02h,03h Key: M = Mandatory support O = Optional support IN = SCSI target port to SCSI initiator port Yes = SCSI Initiator port shall clear the attention condition before last ACK of the Message Out phase. Not required = SCSI Initiator port may or may not clear the attention condition before last ACK of the MES- SAGE OUT phase (see Section 5.1) N/A = Not applicable...

  • Page 101: Disconnect

    Physical Disconnect Time Limit mode parameter (see Seagate SCSI Command Reference Manual, Part number 100293068.) whichever is greater. If this option is disabled or the target is not able to do a physical disconnect at the time when it receives the DISCONNECT message from the initiator, the target shall respond by sending a MESSAGE REJECT message to the initiator.

  • Page 102: Ignore Wide Residue

    DISCPRIV bit, but shall not attempt to switch to another task. (See the DTDC field of the physical disconnect/reconnect mode page in Seagate SCSI Command Reference Manual, Part number 100293068 for additional controls over physical disconnection.)

  • Page 103: Initiator Detected Error

    The ENABLE MODIFY DATA POINTER (EMDP) bit in the Disconnect-reconnect mode page (see Seagate SCSI Command Reference Man- ual, Part number 100293068) indicates whether or not the target is permitted to issue the MODIFY DATA POINTER message.

  • Page 104: Modify Bidirectional Data Pointer

    It is recommended that the target not attempt to move the data pointer outside the range addressed by the command. Initiators may or may not place further restrictions on the acceptable values. Should the target send an Argument value that is not supported by the initiator, the initiator may reject the value by responding with the MESSAGE REJECT message.

  • Page 105: No Operation

    Table 32: MODIFY BIDIRECTIONAL DATA POINTER message format Byte (MSB) (MSB) 4.3.11 NO OPERATION The NO OPERATION message is sent from an initiator in response to a target’s request for a message when the initiator does not currently have any other valid message to send. For example, if the target does not respond to the attention condition until a later phase and at that time the original message is no longer valid the initiator may send the NO OPERATION message when the target switches to a MESSAGE OUT phase.

  • Page 106: Parallel Protocol Request

    4.3.12 PARALLEL PROTOCOL REQUEST PARALLEL PROTOCOL REQUEST messages (see Table 33) are used to negotiate a synchronous data trans- fer agreement, a wide data transfer agreement, and set the protocol options between two SCSI devices. Table 33: PARALLEL PROTOCOL REQUEST message format Byte 7[1] PCOMP...
  • Page 107 See Section 3.5 for an explanation of the differences between ST and DT data transfers. The REQ/ACK OFFSET value is chosen to prevent overflow conditions in the port’s receive buffer and offset counter. The REQ/ACK OFFSET values and which timing values shall be selected are defined below. Value Description Specifies asynchronouse transfer agreement.
  • Page 108 Table 34: Valid protocol options bit combinations QAS_REQ DT_REQ IU_REQ A Parallel Protocol Request agreement applies to all logical units of the two SCSI devices that negotiated agreement. That is, if SCSI device A, acting as an initiator, negotiates a data transfer agreement with SCSI device B (a target), then the same data transfer agreement applies to SCSI devices A and B even if SCSI device B changes to an initiator.

  • Page 109: 1Parallel Protocol Request

    be changed. Each SCSI device when transmitting data shall respect the negotiated limits set by the other's PARALLEL PROTOCOL REQUEST message, but it is permitted to transfer data with larger periods, smaller synchronous REQ/ACK offsets, or both. The completion of an exchange of PARALLEL PROTOCOL REQUEST messages implies an agreement as shown in Table 35.

  • Page 110: Qas Request

    If an abnormal condition prevents the target from responding with a PARALLEL PROTOCOL REQUEST mes- sage or with a MESSAGE REJECT message, then both SCSI devices shall use the eight-bit/asynchronous data transfer mode with all the protocol options bits set zero to indicate ST DATA IN and ST DATA OUT phases between the two SCSI devices.

  • Page 111: Synchronous Data Transfer Request

    4.3.16 SYNCHRONOUS DATA TRANSFER REQUEST Synchronous Data Transfer Request (SDTR) messages (see Table 36) are used to negotiate a synchronous data transfer agreement between two SCSI devices. Table 36: Synchronous Data Transfer Request message format Byte The TRANSFER PERIOD FACTOR field values are defined below. Code Description 00h-07h...
  • Page 112 a. after a HARD RESET; b. after a TARGET RESET message; c. after a power cycle; and d. after a change in the transceiver mode (e.g., LVD mode to MSE mode). Any condition that leaves the data transfer agreement in an indeterminate state shall cause the SCSI device to enter an asynchronous data transfer mode.

  • Page 113: 1Target Initiated Sdtr Negotiation

    4.3.16.1 Target initiated SDTR negotiation If the target recognizes that SDTR negotiation is required, it sends an SDTR message to the initiator. The initi- ator shall create an attention condition on the last byte of the SDTR message from the target, and the initiator shall respond with its SDTR message, MESSAGE PARITY ERROR message, or with a MESSAGE REJECT message.

  • Page 114: Wide Data Transfer Request

    4.3.18 WIDE DATA TRANSFER REQUEST WIDE DATA TRANSFER REQUEST (WDTR) messages (see Table 38) are used to negotiate a wide data transfer agreement between two SCSI devices. Table 38: WIDE DATA TRANSFER REQUEST message format Byte The TRANSFER WIDTH EXPONENT field defines the transfer width to be used during ST DATA IN phases and ST Data Out phases.

  • Page 115: 1Target Initiated Wdtr Negotiation

    fer agreement shall remain intact; b. If a WDTR message fails for any other reason, the prior synchronous data transfer agreement shall remain intact; or c. If a WDTR message is not rejected with a MESSAGE REJECT message, a WDTR message shall reset the synchronous data transfer agreement to asynchronous mode and any protocol option bits (see Sec- tion 4.3.16) shall be set to zero.

  • Page 116: 2Initiator Initiated Wide Data Transfer Request (Wdtr) Negotiation

    get causing an unexpected bus free. The initiator shall accept such action as aborting the WDTR negotiation, and both SCSI devices shall go to eight-bit data transfer mode for data transfers between the two SCSI devices. Any prior synchronous data transfer agreement shall remain intact. 4.3.18.2 Initiator initiated Wide Data Transfer Request (WDTR) negotiation If the initiator recognizes that WDTR negotiation is required, it creates an attention condition and sends a...

  • Page 117: Aca (Auto Contingent Allegiance)

    When a target does a physical reconnection to an initiator to continue a tagged task, the Simple Queue mes- sage shall be sent following the Identify message to resume the I_T_L_Q nexus for the task. Only one I_T_L_Q nexus may occur during a physical reconnection. If the Simple Tag message is not sent, then only an I_T_L nexus occurs for the task (i.e., an untagged command).

  • Page 118: Head Of Queue

    4.4.3 HEAD OF QUEUE See Table 42 for the format of the Head of Queue message. Table 42: Head of Queue message format Byte The Head of Queue message specifies that the task shall be placed in the task set as a Head of Queue task. The rules used by the device server to handle Head of Queue tasks within a task set are defined in Section 7.0 of this manual and in the SCSI Architecture Model-2 standard.

  • Page 119: Task Management Messages

    Task management messages Table 45 lists the codes used for messages that manage tasks. Details about these task management mes- sages is given in subsections following the table. 4.5.1 Task management message codes Table 45: Task management message codes Support Code IU Transfers Disabled IU Transfers Enabled...

  • Page 120: Abort Task Set

    4.5.3 ABORT TASK SET The ABORT TASK SET message is defined in the SCSI Architecture Model-4 standard. In addition to the requirements in the SCSI Architecture Model-4 standard the target shall go to the BUS FREE phase following the successful receipt of the ABORT TASK SET message. If only an I_T nexus has been established, the target shall switch to a BUS FREE phase.

  • Page 121: Miscellaneous Scsi Bus Characteristics

    Miscellaneous SCSI bus characteristics Asynchronous conditions can occur on the SCSI bus that cause a SCSI device to perform certain actions that may alter the phase sequence of an I/O process. Furthermore, SCSI devices may not all be powered on at the same time.

  • Page 122: Bus Reset Condition

    A SCSI target port shall respond to an attention condition with MESSAGE OUT phase as follows: a. If an attention condition is created during a COMMAND phase, the target shall enter MESSAGE OUT phase after transferring part or all of the command descriptor block. b.

  • Page 123: Reset Events

    The effect of the hard reset on tasks that have not completed, SCSI device reservations, and SCSI device operating modes is defined in the SCSI Architecture Model-4 standard. Any SCSI device that detects a hard reset shall also set its transfer agreement to the default transfer agree- ment.

  • Page 124: Active Pointers

    • Active pointers (one set per initiator only). • Saved pointers (one or more sets per initiator, up to fifteen sets total). The use of these two types of pointers is described in the following paragraphs. 5.5.2 Active pointers Active pointers represent the current state of the interface between the initiator and the target that the initiator is currently connected to and servicing.

  • Page 125: Command Processing Considerations And Exception Conditions

    Command processing considerations and exception conditions 5.6.1 Command processing considerations and exception conditions overview The following subclauses describe some aspects of command processing, including exception conditions and error handling that are specific to this standard. 5.6.2 Asynchronous event notification Notification of an asynchronous event is performed using the SEND command with the AER bit set to one. The information identifying the condition being reported shall be returned during the data out delivery phase of the SEND command (see SCSI Primary Commands-4 standard).

  • Page 126: Unexpected Reselection Phase

    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).

  • Page 127: Spi Information Units

    SPI information units An information unit transfer transfers data in SPI information units. The order in which SPI information units are transferred within an information unit transfer follows a prescribed sequence. When information unit transfers are enabled, only SPI information units shall be transferred within the DT DATA OUT phase and DT DATA IN phase.
  • Page 128 Logical reconnections occur on the successful target transmission and initiator receipt of a SPI L_Q informa- tion unit for an existing I/O process. The logical reconnection reestablishes the I_T_L_Q nexus for that I/O pro- cess. SCSI devices using information unit transfers may receive several commands during an initial connection. This occurs when a SCSI initiator port uses the multiple command option in the SPI L_Q information unit.
  • Page 129 DT DATA OUT disconnect) See Table 49 for the format of the SPI L_Q information unit. See Table 46 for the format of the SPI Command information unit. See Figure 16. See Figure 18. Figure 15. SPI information unit sequence during initial connection Parallel SCSI Interface Product Manual, Rev.
  • Page 130 DT DATA IN (from SPI STATUS or SPI DATA) DT DATA IN DT DATA OUT DT DATA IN BUS FREE (physical disconnect) See Table 49 for the format of the SPI L_Q information unit. See Table 52 for the format of the SPI Data information unit. See Figure 18.
  • Page 131 (from SPI STATUS DT DATA IN DT DATA IN DT DATA OUT BUS FREE disconnect) See Table 49 for the format of the SPI L_Q information unit. See Table 53 for the format of the SPI Data information unit. See Figure 18. Figure 17.

  • Page 132: Spi Information Units

    DT DATA OUT (from SPI DATA or SPI COMMAND) DT DATA IN Data Length BUS FREE (physical disconnect) See Table 49 for the format of the SPI L_Q information unit. See Table 54 for the format of the SPI Status information unit. See Figure 16.
  • Page 133 If the Task Management Flags field is a supported value not equal to 00h, the target shall perform the selected task management function before processing any further SPI information units regardless of the command type. On completion of a support task management function, the target shall go to a BUS FREE phase. No SPI status information unit shall be reported for the task management function.
  • Page 134 The Write Data (WRDATA) bit and READ Data (RDDATA) bit are defined in SCSI protocol standards T10/ 1144D (FCP-2), sections 9.1, 9.1.16, and 9.1.17. They are also discussed in the Seagate Fibre Channel Interface Manual, part number 77767496. These two bits are used by drives in a Fibre Channel I/O sys- tem and shall be ignored by this section.

  • Page 135: Spi L_Q Information Unit

    Management Flags field is not zero. Any bytes between the end of a 6 byte CDB, 10 byte CDB, or 12 byte CDB and the end of the CDB field shall be reserved. The Additional CDB field contains any CDB bytes beyond those contained within the standard 16 byte CDB field.
  • Page 136 Byte BIDI Direction [5] The Type field is defined in Table 50. If a SCSI initiator port receives a type code that is not defined in Table 50, that initiator shall follow the procedures defined in Section 3.5.2.2.1.1. If a SCSI target port receives a type code that is not defined in Table 50, that target shall follow the procedures defined in Sec- tion 3.5.2.2.1.2.
  • Page 137 Table 50: SPI L_Q information unit type Codes Type Description Sent by a SCSI initiator port device to indicate a SPI command information unit shall follow this SPI L_Q information unit. Indicates the initiator device shall not send any more SPI com- Last mand information units during the current connection.
  • Page 138 509 would transfer 509 bytes of data plus 3 bytes of pad plus 4 bytes of iuCRC for a total transfer of 516 bytes). The target shall not set the data length to a value that exceeds the maximum burst size as defined in the disconnect-reconnect page (see Seagate SCSI Command Reference Manual, Part number 100293068.) The BIDI Direction field determines the data direction if the command is a bidirectional command and the type code is data or data stream.

  • Page 139: Spi Data Information Unit

    6.2.3 SPI data information unit The SPI data information unit (see Table 52) contains data. The detection of a BUS FREE phase following a SPI data information unit by a SCSI initiator port shall be equivalent to the initiator receiving a DISCONNECT message. The detection of a QAS REQUEST message following a SPI data information unit by a SCSI initiator port shall be equivalent to the initiator receiving a DISCONNECT message.
  • Page 140 tion unit the P_CRCA signal was asserted and a SCSI initiator port detects a REQ transition after receiving the last iuCRC for a SPI data stream information unit, that SCSI initiator shall logically disconnect from the current I_T_L_Q nexus. If, during a sequence of SPI data stream information units a SCSI initiator detects any change to the C/D, I/O, or MSG signals after transmitting or receiving the last iuCRC for a SPI data stream information unit, that initia- tor shall consider the current I/O process to be logically disconnected or in the case of detecting a BUS FREE phase or a MESSAGE IN phase to be physically disconnected.

  • Page 141: Spi Status Information Unit

    6.2.5 SPI status information unit The SPI status information unit (see Table 54) contains the completion status of the task indicated by the pre- ceding SPI L_Q information unit. The target shall consider the SPI status information unit transmission to be successful when there is no attention condition on the transfer of the information unit.
  • Page 142 The Sense Data field contains the information specified by the SCSI Primary Commands-4 (SPC-4), T10/1731- D, for presentation by the REQUEST SENSE command (see Seagate SCSI Command Reference Manual, Part number 100293068). The proper sense data shall be presented when a SCSI status byte of Check Condi- tion is presented as specified by the SCSI Primary Commands-4 (SPC-4), T10/1731-D and this manual.
  • Page 143 The iuCRC field shall use the algorithm defined in Subsection 11.3, ANSI SCSI Parallel Interface (SPI-5), T10/ 1525D. Parallel SCSI Interface Product Manual, Rev. A...
  • Page 144 Parallel SCSI Interface Product Manual, Rev. A...

  • Page 145: Scsi Commands

    SCSI commands This section defines the SCSI command structure and describes a typical SCSI bus procedure involving a command, status return, and message interchange. The command structure defined herein provides for a contiguous set of logical blocks of data to be transferred across the interface.
  • Page 146 For all commands, if there is an invalid parameter in the Command Descriptor Block, the drive shall terminate the command without altering the medium. The format description for the Command Descriptor Block as supported by Seagate drives is shown in tables 57, 58, 59, 60, and 61.

  • Page 147: Fixed And Variable Length Command Descriptor Block Formats

    7.2.1 Fixed and variable length Command Descriptor Block formats For all commands, if there is an invalid parameter in the command descriptor block, the device server termi- nates the command without altering the medium. Table 57 shows the typical format of a 6-byte CDB. Table 58 shows a typical format of a 10-byte CDB. Table 59 shows the typical format of a 12-byte CDB.
  • Page 148 Table 59: Typical CDB for 12-byte commands Byte Reserved (MSB) (MSB) See notes following Table 61. Table 60: Typical CDB for 16-byte commands Byte Reserved (MSB) (MSB) OPERATION CODE [1] SERVICE ACTION (if required) [2] LOGICAL BLOCK ADDRESS (if required) [3] TRANSFER LENGTH (If required) [4] PARAMETER LIST LENGTH (if required) [5] ALLOCATION LENGTH (if required) [6]...
  • Page 149 Byte (MSB) See notes following Table 61. Table 61: Typical variable length CDB Byte (MSB) Notes for Tables 57, 58, 59, 60, and 61. The Operation Code field of the Command Descriptor Block contains the code value indentifying the oper- ation being requested by the CDB.
  • Page 150 8.0 where the details of each command are described. The Logical Block Address on logical units or within a partition on device volumes shall begin with block zero and be contiguous up to the last logical block on that logical unit or within that partition. A six-byte command descriptor block contains a 21-bit Parameter List Length field.
  • Page 151 The ability to support an NACA value of one is indicated in standard INQUIRY data. See Seagate SCSI Command Reference Manual, Part number 100293068. If the NACA bit is set to a value that is not supported, the drive completes the command with a status of Check Condition and a sense key of ILLEGAL REQUEST.

  • Page 152: Status

    Status A Status byte shall be sent from the target to the initiator during the STATUS phase at the termination of each command as specified in Tables 63 and 64 unless the command is cleared by one of the following conditions: 1.

  • Page 153: Status Precedence

    Busy. This status indicates that the logical unit is busy. This status shall be returned whenever a logical unit is unable to accept a command from an otherwise acceptable initiator (i.e., no reservation conflicts). The recom- mended initiator recovery action is to issue the command again at a later time. Intermediate.

  • Page 154: Command Examples

    Command examples 7.4.1 Single command example A typical operation on the SCSI bus is likely to include a single READ command to a peripheral device such as the drive. This operation is described in detail starting with a request from the initiator. This example assumes that no linked commands and no malfunctions or errors occur and is illustrated in Figure 19.

  • Page 155: Disconnect Example

    7.4.2 Disconnect example In the single command example, the length of time necessary to obtain the data may require a time consuming physical seek. In order to improve system throughput, the drive may disconnect from the initiator, freeing the SCSI bus to allow other requests to be sent to other SCSI devices. To do this, the initiator must be reselectable and capable of restoring the pointers upon reconnection.

  • Page 156: Timing Examples

    Timing examples Times (T00 through T35) necessary to define performance are listed in the individual drive’s Product Manual, in the “Disc drive SCSI timing” section. For timing waveforms to define these times, refer to the SCSI Parallel Interface-5 specification (SPI-5). Command processing considerations and exception conditions The following clauses describe some exception conditions and errors associated with command processing and the sequencing of commands.

  • Page 157: Clearing An Auto Contingent Allegiance Condition

    The handling of tasks created by initiators other than the faulted initiator depends on the value in the TST field in the Control mode page (see ANSI SCSI Primary Commands-4, T10/1731-D). If TST=000b, tasks created by other initiators while the ACA or CA condition is in effect shall not be entered into the faulted task set (except for a PERSISTENT RESERVE command with a Preempt and Clear action as described in Section 7.2.1, note [7], Table 62).

  • Page 158: Incorrect Logical Unit Selection

    INQUIRY command the target shall return the INQUIRY data with the peripheral qualifier set to the value required in Seagate SCSI Command Reference Manual, Part number 100293068. In response to REQUEST SENSE, the target shall return sense data.

  • Page 159: Autosense

    The control mode page contains parameters affecting the use of asynchronous event reporting (see Seagate SCSI Command Reference Manual, Part number 100293068). Asynchronous Event Reporting is used to signal a device that one of the four events listed below has occurred: a.

  • Page 160: Unit Attention Condition

    The version or level of microcode has changed. m. The logical unit inventory has been changed (not generally applicable to Seagate disc drives); or n. A change in the condition of a synchronized spindle occurred (not generally applicable to Seagate disc drives).

  • Page 161: Target Hard Reset

    7.6.7 Target hard reset a SCSI target port hard reset is a SCSI target port response to a SCSI target port Reset task management request (see SCSI Architecture Model-4, T10/1157D), or a reset event within the service delivery subsystem. The definition of target reset events is protocol and interconnect specific. Each SCSI product standard shall specify the response to a SCSI target port reset event including the conditions under which a SCSI target port hard reset shall be executed.

  • Page 162: Tagged Task Queuing

    Control Mode page (see Seagate SCSI Command Reference Manual, Part number 100293068). The command ordering is done by the drive to meet its performance and functional goals. The algorithm used by the drive attempts to achieve certain drive or system performance goals established in the drive firmware for the queued commands and guarantee that all commands will be executed.

  • Page 163: Parameter Rounding

    In some vendor-specific cases, it may also be necessary to perform other commands including MODE SENSE and READ CAPACITY. The more recent Seagate drives do not support the Change Operating Definition command (see individual drive’s Product Manual). Each logical unit begins at a particular operating definition. If the logical unit supports the CHANGE DEFINI- TION command, the present operating definition can be changed to any other operating definition supported by the logical unit.

  • Page 164: Incorrect Initiator Connection

    Since new operating definitions may preclude the execution of tasks that are already in progress, the target may disconnect to allow completion of any tasks that are in progress. Operating definition changes that may cause conflicts with the normal operation from other initiators shall be indicated to those initiators by generating a Unit Attention condition for each other initiator.

  • Page 165: Drive Features

    Control page 1Ch. The drive reports information about S.M.A.R.T. operation using REQUEST SENSE Addi- tional Sense Code 5D 00 and MODE SENSE data page 1Ch. Refer to Seagate SCSI Command Reference Manual, Part number 100293068 for the description of the MODE SELECT/MODE SENSE commands and for more details on the Informational Exceptions Control page.

  • Page 166: Self-Test Modes

    ABORT TASK SET, or Clear Task Set task management function while performing a self-test in the foreground mode, the it shall abort the self-test and update the Self-test results log page (see Seagate SCSI Command Reference Manual, Part number 100293068).

  • Page 167: Elements Common To Foreground And Background Self-Test Modes

    Elements common to foreground and background self-test modes The Progress Indication field returned in response to a REQUEST SENSE command (see Seagate SCSI Command Reference Manual, Part number 100293068) may be used by the application client at any time dur- ing execution of a self-test to poll the logical unit’s progress.

  • Page 168: Message, And Status

    Not Ready sense key, and Logical Unit Not Ready, Self-Test In Progress additional sense code. Process the command, except as described in Seagate SCSI Command Reference Manual, Part number 100293068. Parallel SCSI Interface Product Manual, Rev. A Self-test failure reporting...

  • Page 169: Covered Signals

    8.3.2.1 Covered signals Table 67 defines the signals to be covered by the protection code and their bit locations in the 21-bit code word. When a SCSI device receives an information byte, it also latches the state of the other SCSI signals and values noted in Table 67.
  • Page 170 For each new run, the Sequence ID is set to zero for the first word transferred, set to one for the second word transferred, set to two for the third word transferred, and set to three for the fourth word transferred. The Sequence ID then cycles back to being set to zero for the fifth word transferred, and so forth until the run is complete.

  • Page 171: Code Description

    8.3.2.2 Code description The protection code (see Table 68) is a cyclic binary BCH code. Table 68: Protection code Number of Maximum data redundant Code bits allowed bits (21,15,4) The BCH protection code is a cyclic code with a generator polynomial of x 6 + x 5 + x 2 + 1. The canonical form of the code generator is shown in Figure 21.

  • Page 172: Protection Code Transmission

    8.3.3.1 Protection code transmission SCSI devices supporting this protection code transmit the protection code check data during all Command, Message, and STATUS phases. The protection code byte is transferred on the upper eight bits of a wide bus simultaneously with the information day byte on the lower eight bits of the bus using the same clock for the transfer.

  • Page 173: Case 1—Power Off During Removal Or Insertion

    8.4.2 Case 1—Power off during removal or insertion a. All SCSI devices are powered off during physical reconfiguration. 8.4.3 Case 2—RST signal asserted continuously during removal or insertion a. RST signal shall be asserted continuously by the initiator during removal or insertion. b.

  • Page 174: Spi-3 To Scsi-2 Terminology Mapping

    c. A SCSI device being removed shall maintain its power ground and logic ground prior to, during, and for at least 1 ms after the disconnection of any device connector contact from the SCSI bus. d. The SCSI device being removed or inserted shall employ transceivers that conform to the applicable requirements in ANSI SPI-5 specification, T10/1525D, sections 7.2.2 and 7.3.5.3 for glitch-free powering on and off.
  • Page 175 Index abort message 138 abort task 138 abort task message 105 abort task set message 106 aborted command 4, 143, 150 ACA. see Auto Contingent Allegiance ACK. see Acknowledge acknowledge SCSI bus signal 15 active pointer 110, 140 adapter host 14 Additional CDB SPI command information unit 119, 121 Additional CDB Length...
  • Page 176 code value reserved 131 command 4, 6 aborted 4 completed 5 ended 6 linked 7 overlapped 143 SCSI-3 standards 2 single, example 140 third party 11 unlinked 11 untagged 149 command complete message 140, 141 command completion 131 command data 5 command data signal 29 Command Descriptor Block SPI command information unit 119, 120...
  • Page 177 disconnect privilege 148 domain 5, 9 dormant task state 5 double transition 6 DP-1 signals 34 drive select 17 driver 6 driver precompensation 36 DT Data In 5 DT Data In phase 5, 38 DT Data Out 5 DT Data Out phase 38 DT Data phase 7, 38 DT DATA phases 37 DT Data phases 31, 34...
  • Page 178 information unit sequence 113 information unit transfer 6, 38 initial connection 6 initiator 3, 6, 14, 131, 140 faulted 6 multiple 3, 14 single 14 initiator connection incorrect 150 initiator detected error message 89 initiator port 13 input/output SCSI bus signal 15 input/output.
  • Page 179 multidrop 7 multimode SCSI bus signal 15 multimode I/O circuits 15 multimode single-ended 7 multiple initiator 14 multiple initiators 3 multiple target 14 NACA. see Normal Auto Contingent Allegiance negated edge 6 negotiate 40 negotiation 40 negotiation message sequences 49 nexus 6, 8 no operation message 91 non-recoverable error 9...
  • Page 180 protection code error 158 protection code generator 157 protection code transmission 158 protocol 8 layer 9 lower level 7 option 8 SCSI 9 SCSI-3 standards 2 service confirmation 8 service indication 8 service request 9 service response 9 service, unconfirmed 11 upper level 11 protocol option bits 92 protocol options 45...
  • Page 181 RSPVALID. see Packetized Failures Valid RST. see Reset save data pointer message 96, 141 saved pointer 110 SCSI standards, scope of 2 SCSI application layer 9 protocol transaction 9 SCSI architecture model SCSI-3 standards 2 SCSI bus 13, 140, 141 procedure 131 signals 15 timing 20...
  • Page 182 SPI status information unit 113, 127 ST Data phase parallel transfers 38 ST DATA phases 37 ST LVD phases 34 state of the bus 6 Status SPI status information unit 127, 128 status 6, 138 status byte 131, 138 status phase 138 status precedence 139 status response 5 stored pointer 140...
  • Page 183 two-byte message 84 Type SPI L_Q information unit 121, 122 Ultra160 1 Ultra320 1 unconfirmed protocol service 11 unexpected bus free 138 unit attention condition 146, 150 unit attention mode parameters page 146 unit attention parameters 146 unit attention sense key 146 unlinked command 11 untagged command 149 untagged task 143...
  • Page 184 Parallel SCSI Interface Product Manual, Rev. A...
  • Page 186 Seagate Technology LLC 920 Disc Drive, Scotts Valley, California 95066-4544, USA Publication Number: 100293069, Rev. A, Printed in USA...

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